When the chemical industry talks about prioritization – a central question in the debate over TSCA reform – more often than not it quickly reduces the question down to the argument that we should focus only on those chemicals, however hazardous or untested they may be, to which we know people are exposed.  In a perfect world, that might suffice.  But, as this post will explore, the world of exposure assessment is anything but perfect. 

While both hazard and exposure are clearly relevant in determining chemical risks, there are critical differences between our ability to assess hazard and exposure that have implications for the development and application of chemicals policies.  And real-world experience in chemical assessment programs that have attempted to rely on exposure information to prioritize chemicals also offers lessons for exposure assessment.

Critical differences between assessing hazard and exposure

Approaches that seek to rely on exposure to prioritize or assess chemicals need to acknowledge and account for a number of critical differences between the nature of hazard and exposure information and their relative extent of availability.  Certain characteristics of exposure information pose serious challenges to sound decision-making.  Here are several reasons why.

1.  Hazard is largely inherent to a chemical and (aside from degradation or metabolism) doesn’t fundamentally change over space or time, whereas any exposure information necessarily represents only a “snapshot” in both space and time.

A chemical’s hazard is an intrinsic property, one that is directly related to the chemical's composition.  While manifestation of a hazard can of course vary by route of exposure, it otherwise exists largely independent of how the chemical is used, where or how it enters the environment, or other factors that vary with time and place.  Hazard data are therefore relevant and needed regardless of how the chemical is used.  That is, such data are useful in understanding any actual or potential use or release of a chemical – and in deciding what kind of exposure-reducing efforts may need to be taken.

Just the opposite is true for exposure, which can change dramatically depending on how a chemical is produced, used, transported and discarded or released.  The consequences of exposure depend on who or what might be exposed, and the level, frequency and duration of the exposure. 

Conditions that determine exposure can and often do differ enormously for every setting and point in time that a chemical is present.  Basic physiological differences (including those associated with age and life stage) as well as cultural factors (e.g., extent of fish consumption) and activity patterns also amplify the variability in exposure to a chemical.  And even if a “snapshot” of current exposure is able to be assembled, the next new use or activity leading to a release alters the exposure picture.

The highly variable nature of exposure poses a major challenge to exposure (and risk) assessment:  It means that exposure assessment must be an ongoing activity, with the scope and frequency of its measurement sufficient to characterize the variation (spatial and temporal) in, as well as magnitude of, exposure. 

That's but one reason why exposure assessment is often called the "weakest link" in risk assessment.

2.  Mechanisms for generating and collecting exposure information are undeveloped relative to those for hazard information.

An extensive body of methods developed through international consensus specifies how to test a chemical for most hazardous properties.  And while new hazard concerns and new test methods emerge over time and must be incorporated, the infrastructure for doing so is largely in place:  detailed government-sanctioned procedures, guidelines, criteria and standards have been specified for conducting hazard tests, for assuring the quality and reliability of the results, and for determining whether the results constitute evidence of a particular hazard.  Moreover, these measures allow that results are reproducible and can be independently verified.

In contrast, virtually none of these mechanisms are in place or established to assure that exposure information is complete and accurate.  Debates over what constitutes adequate exposure assessment and how to address the “moving target” nature of such information are far from resolved.  Government-sanctioned procedures for generating, evaluating the adequacy of and interpreting exposure data have yet to be developed or validated, including testing and measurement standards, guidance, methods and tools.

Use and exposure information is rarely systematically collected and even less often made public in any useful form.  For the first time, beginning in 2006, the Environmental Protection Agency (EPA) began to require the reporting of basic information relevant to understanding uses of and exposure to chemicals.  But that program is fraught with limitations, as I've described in detail in earlier posts here and here.

Because of these and other factors, estimates of chemical exposures typically depend on severely limited sources of information.  In many instances, little or no information is publicly available on how chemicals are manufactured, processed, used, or discarded; the numbers of workers and consumers exposed; quantities released to the environment; how chemicals are distributed and transformed in the environment; and other parameters necessary for estimating exposures. 

3.  Assumptions and modeling used to characterize exposure are notoriously inaccurate.

As a result of the information constraints just discussed, exposure-driven prioritization initiatives and exposure modeling exercises may well utilize incorrect exposure assumptions.  Biomonitoring has revealed such instances by “ground-truthing” exposure assumptions – providing objective, incontrovertible evidence of the extent to which chemicals end up in people.  Recent biomonitoring data on both phthalates and poly-brominated diphenyl ethers amply illustrate this point. 

Phthalates are very widely used in products ranging from plastics to cosmetics and other personal care products.  They exhibit a range of toxicity, including to the liver, kidney, and male reproductive system.  The first CDC National Report demonstrated surprisingly high levels of di-butyl phthalate (DBP) and di-ethyl phthalate (DEP) in U.S. residents in general, and for DBP, in women of child-bearing age in particular (see the first two letters here).  Indeed, these data demonstrated high-end levels of DBP that were an order of magnitude higher than a prior estimate that had been developed based on industry-provided use data and expert judgment.

Polybrominated diphenyl ethers (PBDEs) are widely used flame retardants.  Different species of PBDEs are used in products ranging from plastics (such as computer cases) to upholstery foam.  Toxicological studies indicate that they can disrupt thyroid metabolism and may have effects on other organs, including the liver.  Because PBDEs are not very volatile or water soluble, they were assumed to more or less stay in place in products, and were not believed to have a high potential for exposure.  However, biomonitoring studies from around the world have demonstrated that levels of PBDEs in peoples’ bodies have been dramatically increasing over the past two decades, with the highest levels currently reported in the United States; see, for example, this paper).

4.  Differential access to both exposure data and the means to generate them severely limit the “reproducibility” of such data.

In addition to the variability and absence of agreed-upon procedures noted above, other factors limit “reproducibility,” that is, the ability to readily and independently measure or verify exposure data.  Most exposure data and the means to generate them reside virtually exclusively with industry.  It simply must be acknowledged that industry has a strong interest in maintaining that exposure to its chemicals is low, so the ability to independently measure and verify exposure data is critical.  Yet physical access to many exposure “settings” (e.g., workplaces) is very limited and infrequent at best, even for government officials. 

Broader access to exposure-relevant information is even more restricted:  Wide latitude is typically provided to claim chemical use and exposure information as CBI, preventing even its review outside government; this situation is often in contrast to that applying to hazard data, which is more likely to be deemed ineligible from designation as CBI. 

Finally, even chemical manufacturers have incomplete access to and information on their customers and how their chemicals are used.  Intermediaries (vendors, brokers, distributors) are a formidable information flow bottleneck, as is the often-proprietary nature of information concerning downstream use and competition among suppliers.  These factors serve to impede information-sharing even within supply chains, which in turn affects the extent and accuracy of exposure-relevant information that any one entity in a supply chain can provide if asked or required to do so; see this paper and Modules 1 and 2 of this report for more discussion of these limitations.

Conclusion

For all of these reasons, we cannot continue to rely on assumptions about chemical exposure or on the industry-supplied or otherwise-limited exposure information that is currently available.   That is simply too uncertain and unreliable a basis on which to set aside hazardous or untested chemicals as low-priority, or to decide for which chemicals hazard data should be developed. 

Of course, where affirmative evidence indicates exposure to a chemical is occurring, for example as revealed through biomonitoring, this should clearly suffice to prioritize such a chemical at a minimum for further testing, assessment or control.  But the converse cannot be said:  that in the absence of reliable information about exposure we can simply drop a chemical from further consideration.

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There is actually considerable real-world experience that documents the adverse consequences of an over-reliance on exposure to prioritize chemicals.  For more detail, see our analyses of:

• EPA's recently replaced ChAMP Initiative;
• Canada's Chemical Categorization; and
• the Existing Chemicals Program of the Organization for Economic Cooperation and Development (OECD) – see the paper included as pages 109-114 of this OECD report, which I wrote several years ago and from which this post is derived.

Today, EPA Administrator Lisa Jackson unveiled the Obama Administration's "Essential Principles for Reform of Chemicals Management Legislation."  The principles' significance lies not so much in the words they contain, but rather in what they symbolize:  A clear confirmation that this Administration understands that the Toxic Substances Control Act (TSCA) needs fundamental reform and that it is ready and willing to engage in making it happen.

There's no shortage of principles and platforms for TSCA reform, of course.  See my earlier post comparing and contrasting the platform of the Safer Chemicals, Healthy Families coalition – of which EDF is a member – with the American Chemistry Council (ACC) "principles for modernizing TSCA.”

So what does EPA's entrance into the fray mean?   It is a real sea change to have the very agency charged with implementing TSCA be willing to say the law isn't working, that it doesn't provide EPA with the tools it need to do its job.

Who would know better than EPA?

For the first time EPA is publicly affirming it needs substantially greater authority if it is to protect human health and the environment from dangerous chemicals.  And the preamble to the principles makes clear that EPA stands ready to engage, to work for TSCA reform, and that such reform should happen "quickly."  That's great news, and a major reversal from the last EPA's view that TSCA was working just fine as is.

It's also noteworthy that Ms. Jackson identified the principles as those of the Obama Administration, not just EPA.  That reflects the fact that they went through a thorough interagency review process – and it also means they have the backing of the White House.

I'm not going to attempt to dissect or parse in detail the new Administration principles here.  I'll only say they encompass most of the elements EDF and others have for years been arguing are essential to TSCA reform, including:

• a requirement that industry develop and provide to EPA the data needed to determine whether chemicals – both new and existing – are safe;
• far greater and easier authority for EPA to require additional testing of chemicals;
• assessment of chemical safety against a health-based standard, rather than the cost-benefit "unreasonable risk" standard that has been the downfall of the current TSCA;
• an obligation to address the higher risks to sensitive subpopulations, including children, workers and communities suffering disproportionate impacts from chemicals;
• authority to reassess safety when a chemical's production or use changes or new information emerges;
• authority to require use and exposure information from downstream users as well as chemical makers;
• narrowing the ability of industry to claim its submissions as confidential business information, and requiring an up-front justification for any such claims; and
• the need for a dedicated source of funding to support EPA's implementation of TSCA, derived from chemical manufacturers.

Not a bad start for the new leadership at EPA.

Today, the American Chemistry Council (ACC) unveiled its "10 Principles for Modernizing TSCA."  Also today, the Safer Chemicals, Healthy Families coalition – of which EDF is a member – issued a news release and unveiled its 9-point "Platform for Reform of TSCA."  How do they line up?

I'll leave to you readers to decide just how much alignment (or lack thereof) there is between these dueling manifestos.  To get the ball rolling, I'll use this post to single out three key differences.

First, however, let me say I welcome the fact that ACC is finally moving beyond rhetorical flourishes about "modernization" and "the need to restore public confidence in its products."  At last ACC has begun to provide something that could become something that one can sink one's teeth into.

Equally refreshing is that ACC is now acknowledging a number of deep problems with TSCA that it has traditionally denied – problems that many of us having been raising for years.  To be specific:

• TSCA does not require that chemicals be shown to be safe in order to be on the market.
• TSCA's reliance on a cost-benefit rather than a health-based standard to determine safety was ill-advised.
• EPA should be required to complete safety assessments expeditiously and within clear deadlines.
• Companies throughout the supply chain, not just manufacturers, should be required to provide information on chemical use and exposure, as well as hazards.
• Children are at particular risk from chemical exposures and merit special protection.
• EPA lacks but should be given authority it can actually exercise to regulate chemicals.
• EPA shouldn't have to prove risk to require testing of chemicals.
• The public should have access to chemical use and exposure, as well as hazard, information.

That's all good and welcome news.  ACC has come a long way, baby.

But let's scratch below the surface a bit, and we'll see some fundamental differences quickly begin to emerge.

1.  What ACC wants:  ACC clearly wants the focus to be on only a few "priority" chemicals, and seeks to set aside the rest.  Indeed, ACC's principles go even further to say we should skip over all but the "most significant uses and exposures" of the priority chemicals, and then narrow things even more to consider only their "intended" uses.

What we actually need:  Robust data on all chemicals, not just the few we already know are bad actors.  A full understanding of all chemical uses, not just those chemical producers have knowledge of and consider most significant.  Authority for EPA to act promptly to control chemicals we already know are high-priority.

As readers of this blog know full well, the problem with ACC's approach is that it puts the cart before the horse:  The state of knowledge about chemical hazards, uses and exposures remains poor despite more than three decades of life under TSCA – so poor that we can't begin intelligently to prioritize most chemicals.

One particularly huge gap in knowledge is about the full range of uses of chemicals.  As I've discussed before, companies that make chemicals often don't know how and by whom their own chemicals are used – not even for the uses they intend for them, let alone those they may never have anticipated.  That yields a very spotty picture of real-world exposures – which may help to explain why time and again government and industry have failed to predict which chemicals we're all exposed to, let alone how or to what extent.

Hazard information about a chemical is of value regardless of its use, and can help enormously to guide selections among alternatives when considering a new or revisiting a current use.  Yet, in the name of prioritization, ACC would have us utilize various imperfect surrogates for exposure – production volume, known uses, etc. – to severely limit the number of chemicals whose hazards we would ever test for.

The evident gaps in hazard, use and exposure data add up to an inability both to prioritize and to decide a priori what's safe or not.  What's needed instead is a systematic and thorough – not piecemeal – approach, both to getting better information about chemicals, and to assessing their safety.  That's why we call for the development of at least basic information for all chemicals, and a requirement that all chemicals be shown to be safe, not just those we think might be problems based largely on supposition.

     Prioritization is a means, not an end

We fully recognize that undertaking the extent of information development and assessment needed to ensure chemical safety cannot happen overnight, given the depth of the hole that TSCA dug by grandfathering in tens of thousands of untested and unassessed chemicals – which still today account for the great majority of chemicals in use.  We welcome a legitimate debate over how fast and how best we can do all of what's needed, but not one over whether we need to.

It's one thing to prioritize chemicals to determine the order in which their safety should be determined, as long as we ultimately reach all chemicals; it's quite another to place such false confidence in priority-setting as to, as ACC proposes, sweep away most chemicals from ever being tested or assessed.

Now, none of this is to say we have to wait to control those chemicals we already know will rise to the top of anyone's priority list, such as chemicals possessing that deadly trifecta of properties of persistence, bioaccumulation potential and toxicity – the so-called PBTs – to which we know people are being exposed.  That's why we support moving expeditiously to phase such chemicals out of commerce, retaining them only for the most critical uses where no viable alternatives exist.  And we can and should be immediately taking steps to reduce exposure to other dangerous, well-studied chemicals, such as formaldehyde.

2.  What ACC wants:  ACC wants any requirements for testing or monitoring to be imposed by EPA strictly on a case-by-case basis.

What we actually need:  Minimum hazard, use and exposure data sets on all chemicals, delivered up-front, not upon request.  A major expansion in biomonitoring to encompass all chemicals with the potential for human exposure.

While ACC would free EPA at last from the Catch-22 of first having to prove risk to require testing, it would still retain significant evidentiary burdens on EPA to show that having access to data is "reasonably necessary to make safe use determinations."  Huh?

ACC remains intent on avoiding the development of robust, consistent information across chemicals in commerce.  As we've argued before, there's an inherent contradiction here, given that ACC is among the first to cry "regrettable substitution" when insufficient attention is given to what will replace a chemical targeted for restrictions.  How are we ever to compare alternatives and select safer ones with confidence without good information about them?

EDF and the Safer Chemicals, Healthy Families coalition believe that prioritization must be based, not on the current state of data gaps and supposition, but on a firm foundation of public knowledge that will only come by requiring a minimum data set for all chemicals as a condition for entering or remaining on the market.

3.  What ACC wants:  ACC wants to continue to pretend that people and the environment are somehow able to distinguish between multiple exposures to the same chemical just because they're regulated under different laws or by different agencies.

What we actually need:  An agency (EPA) charged with conducting a holistic assessment across the aggregate of all uses and sources of exposure to chemicals.  And for chemicals that cannot be shown to be safe, the authority and responsibility to ensure that appropriate action is taken regardless of which agency or law has primary jurisdiction.

A major failing of our chemicals policies is that no one is charged with assembling a full picture of exposure to a given chemical, let alone regulating it on that basis.

Name a chemical in the headlines over the last few years – phthalates, bisphenol A, PFOA – and you're looking at a chemical with uses that span agency jurisdictions.  Phthalates in cosmetics fall on FDA's turf, while those in toys fall to the Consumer Product Safety Commission.  ACC would have us continue that atomized approach, where different agencies look at one product at a time, using inconsistent methodologies to measure and assess risk.

And people are exposed to a given chemical not just through its use in products, but through their workplaces, in air and water, and in some cases because of past uses that have yielded "legacies" of exposure, for example from contaminated dump sites or brownfields.  Different offices at EPA are in charge of each of these areas and operate under different statutory authorities.

TSCA need not be the "statute of last resort"

It is with good reason that TSCA is often called the "statute of last resort," because under it EPA must defer to any other statute that could potentially address a problem.  This is an ironic shame, but TSCA is unique among statutes in its intent (at least on paper) to address the full lifecycle of chemicals.  This feature offered the hope – unrealized – that TSCA would break down the silos that artificially divide chemical exposures into neat little, unrealistic bits.

We seek to restore that latent promise of TSCA, by requiring EPA to assess aggregate exposures and risks, across all uses of and sources of exposures to a chemical.  And if a chemical is found unsafe due to uses or exposure sources, some of which fall under another law or agency's jurisdiction, then TSCA should ensure that EPA has the authority and responsibility to ensure either that the other agency or office within EPA takes actions needed to restore safety – or, if it doesn't, that EPA acts under TSCA.

___ 

So, we welcome ACC in at last joining a serious debate over the future of TSCA.  But it still has a long way to go to help the rest of us bring TSCA into the 21^st century.

Some time back, I promised a look at whether Canada's Chemical Management Plan provides a model for TSCA reform.  This post will provide that look.  Bottom line:  While our neighbor to the north has undertaken and accomplished a great deal over the past decade, it has done so with one hand tied behind its back. 

Canada's activism on chemical safety issues is remarkable, given that Canada has only about 2% of the global chemicals market, and that a large fraction of the chemicals used there is imported.  Population-wise, it's also much smaller than the US.  Yet Canada was the first country in the world to tackle the huge legacy of un- and under-assessed chemicals that were – as with TSCA in the US – grandfathered into its regulatory system decades ago.

What did Canada do?

In the 1990's, concern was mounting among the Canadian public in response to increasing evidence of widespread exposure to hazardous chemicals, especially those that are persistent or bioaccumulative, as well as toxic (PBT) chemicals, which were accumulating in wildlife and people even in remote regions of the Arctic.  That concern culminated in amendments to the Canadian Environmental Protection Act (CEPA), adopted by Parliament in 1999. 

CEPA 1999 mandated a novel approach to identifying and initiating government action on chemicals of concern.  It called for two government agencies – Health Canada and Environment Canada – to review all 23,000 previously unassessed chemicals listed on its Domestic Substances List (DSL), Canada's counterpart to the US TSCA Inventory.

Relying on existing information, government was to "categorize" all of these chemicals, by developing and applying specific criteria to identify those that:

• may present, to individuals in Canada, the greatest potential for exposure; or
• are persistent or bioaccumulative and inherently toxic to human beings or to nonhuman organisms.

CEPA 1999 also mandated that this large task be done within seven years of enactment.  Given that legislative mandate and a strict deadline, it not only got done – it got done on time.

This effort remains the most ambitious initiative undertaken to date by any region of the world to examine large numbers of existing chemicals to identify those requiring further data development, assessment and management.

What was the outcome?

Going into the DSL Categorization, most observers expected at most a few hundred chemicals would be "categorized in," i.e., meet one or more of the hazard or exposure criteria noted above.  Instead, more than 4,000 chemicals were found to have one or more of the characteristics of concern.  That, in my view, puts to rest any notion that only a small number of chemicals possess properties of potential concern.

The Canadian government then prioritized among these, identifying about 500 as high priority for action.  Most of these are PBTs, though some showed evidence of high human toxicity without being persistent or bioaccumulative.

CEPA 1999 also mandated that screening-level risk assessments be done on all chemicals that were "categorized in."  It also required that:

• affirmative decisions be made, based on such assessments, to take no further action, to place the chemical on the Priority Substance List, or to place it on the List of Toxic Substances;
• for chemicals placed on the Priority Substance List, to decide based on a more detailed assessment whether or not to place it on the List of Toxic Substances, and to do so within at most five years; and
• for chemicals placed on the List of Toxic Substances, to develop and propose a management strategy within two years, and finalize and begin implementing that strategy within another 18 months.

Canada has been plugging away at these tasks since completing the DSL categorization in September, 2006.

Mandatory assessments?  Affirmative decisions?  Mandatory management strategies?  And deadlines for all of the above?

I must be dreaming – none of this is required for existing chemicals under TSCA!

So, what's not to like about Canada's system?

Here's the hand that was tied behind Canada's back:  It was forced to rely on already available information, however limited it was.  And it was indeed limited.

Hazard data:  Overshadowed by how many chemicals Canada "categorized in" is the fact that there were also thousands of chemicals for which sufficient data did not exist to allow categorization.  For example, for the more than 11,000 organic substances examined, database searches found:

• experimental bioaccumulation data for 410 substances, and one-quarter of these data was of acceptable quality;
• experimental persistence data for 850 substances, and one-third of these data was of acceptable quality; and
• experimental data on inherent toxicity to nonhuman organisms for 1,051 substances, and three-quarters of these data were of acceptable quality.

To try to make some headway in the face of these huge data gaps, and given its lack of a mandate to compel testing, Environment Canada had to rely heavily on estimation models.  And while it managed to cobble together enough data and estimates to categorize most chemicals, thousands were not categorized or were done so at less than a high-confidence level.

Health Canada, in seeking evidence of toxicity to humans, employed a different approach, in which it ranked health endpoints in a hierarchy of more to less serious.  Failure to identify data for a high-concern endpoint simply bounced the chemical down the hierarchy.  Unlike Environment Canada, Health Canada did not reveal the extent of data gaps, but surely they were large as well.

Unfortunately, given the large number of chemicals that were categorized in and the limited resources of the agencies (remember, Canada has a population one-tenth that of the US), scant attention has been paid to filling data gaps.

Exposure data:  Under CEPA 1999, Health Canada was to identify DSL chemicals posing the Greatest Potential for Exposure (GPE) to Humans.  But the data gap was even worse for production, use and exposure information than for hazard data.  The information available to Canada was exceedingly old, dating back to when the DSL was first developed, between 1984 and 1986.

Because of this, and the lack of a routine reporting requirement, Canada is finding that many of the chemicals it categorized in based on their hazards or high exposure potential are no longer manufactured or used in Canada.  Unfortunately, the same data gap raises the converse critical question: How many chemicals that were not manufactured or used in significant quantities in the mid-1980s are today, and hence pose a risk of significant exposure not captured through the DSL Categorization?

At least TSCA has an updating mechanism, called the TSCA Inventory Update Rule (IUR).  But that system is infrequent, incomplete and riddled with exemptions, too-high-reporting thresholds, and other loopholes; see here and here.

Conclusion

While much can be learned from the Canadian experience, it is not a sufficient model for US reform.  Industry likes it (see here, for example) – I suspect in large part because it puts very little burden on them, and a lot on government.  That's one thing when you're dealing primarily with imports, quite another when you're dealing with producers – and the biggest market for chemicals of any country in the world.  We can and should do better.

When it comes to prioritization, the basic choice is between:

• muddling through with whatever data can be cobbled together and then addressing whatever happens to rise to the top; OR
• acknowledging that available data are insufficient to effectively prioritize among chemicals, and therefore first collecting a good baseline of data, and then using that to prioritize.

In addition to relying on incomplete and insufficient hazard data for the great majority of chemicals and employing questionable, ill-informed assumptions about use and exposure (that sounds a lot like EPA's ChAMP initiative before it was suspended), the former approach risks focusing only on those chemicals about which we already know enough to know they're problems, while ignoring the rest – the proverbial looking for car keys lost somewhere in the parking lot at night only under the streetlights because the light is better there. 

That approach also fails to allow us to identify with confidence what could be safer chemicals and avoid so-called "regrettable substitutions," because even if limited available data don't show a problem, what we don't know about such chemicals could still hurt us.

This new post serves as a response to Charlie Auer's most recent comment responding to our critique of ChAMP.  (To see the whole exchange, start here, then go here, here and here.)  So far, this exchange has focused mainly on our disagreement over whether or not EPA is somehow required to do risk assessments under ChAMP.  At some point, I hope Charlie and others will engage on the substance of our critique – the serious concerns we've raised about the quality and validity of the ChAMP assessments.
 

Risk-based at all costs?

In Charlie's latest comment, his main interest seems to be to lock in EPA's current approach under ChAMP.  He steadfastly maintains that EPA now has no choice but to turn out risk decisions for HPV chemicals under ChAMP, given its 2007 commitment under the Security and Prosperity Partnership (SPP) signed by President Bush. 

For all the reasons I've stated earlier, I strongly dispute that conclusion.  Indeed, it is striking how the chemical section of the SPP agreement – including the very language Charlie cites ("the three countries [are] to enhance appropriate coordination in areas including testing, research, information gathering, assessment, and risk management actions") – seems to go out of its way to avoid linking the words "risk" and "assessment."  That term never appears.

I don't dispute, as Charlie says, that "US and Canadian [regulatory] actions are risk-based."  Indeed, EDF supports the view that, in most cases, chemical regulatory actions ought to be risk-based, or certainly ought to take into account both hazard and exposure.

Now, if ChAMP were actually proposing any actions to mitigate risk, e.g., to restrict production or use of any HPV chemicals through regulation, Charlie's argument might be germane.  But as we've noted, ChAMP's not doing that, even for the few chemicals it has designated to be of high risk and high priority.

So the fact that EPA will only consider regulating a chemical based on risk in no way requires that EPA must do risk assessments under ChAMP – regardless of whether the data available to the agency are sufficient to support such assessments. 

Indeed, the SPP agreement was signed well before the use and exposure information EPA has collected under the Inventory Update Rule (IUR) were made public and its major deficiencies were realized.  I disagree with Charlie that the mere fact that EPA collected such data compels it to use them regardless of their adequacy.

As we noted in our last two posts on ChAMP, in cases where hazard concerns warrant action, there are lots of steps the agency could be taking to manage or reduce potential risks – without having to wait for the emergence of use and exposure data of sufficient quality to carry out a risk assessment.  EPA itself has taken such actions occasionally, for example in launching the 2010/2015 PFOA Stewardship Program.

Sacrificing the public's chemical right-to-know on the altar of risk

Add to this the fact that EPA's insistence on pursuing the "rush to risk" under ChAMP is delaying the public's right-to-know about the hazards of HPV chemicals, and I have to strongly question the wisdom of EPA's devoting most of its limited chemical program resources to doggedly pursuing this course.

I also am disturbed by Charlie's conclusion that his and EPA's interpretation of the SPP commitments "are superior to and overtake informal EPA commitments made to pursue the NPPTAC recommendation."   Recall that NPPTAC recommended, and EPA agreed, that the agency issue hazard characterizations and identify remaining data gaps for some 1,200 HPV chemicals by the end of 2009, which it's nowhere closing to meeting.

What NPPTAC called for did not come out of thin air:  It reflected the core purpose of the HPV Challenge, which was in turn the cornerstone of EPA's much-touted chemical right-to-know initiative:  It would be tragic indeed if EPA chooses to negate its public right-to-know commitments by saying they've been trumped by a political decision made by the last administration.

Under ChAMP, the minimum data set has become wholly optional

Charlie cites OECD guidance calling for integrating exposure considerations into assessment activities.  We have no quarrel with that, as long as the exposure information is sufficient; but as our examples amply demonstrate, that is not the case with the IUR data.

Nor does consideration of exposure in any way obviate the need for a complete Screening Information Data Set (SIDS).  International experts convened by the OECD, including from the U.S., devised the SIDS to be the minimum amount of hazard data needed on which to base a screening-level assessment.  EPA itself has repeatedly acknowledged this fact; see, for example, p. 15 of this EPA report on the HPV Challenge.  Outside of some very limited derogations (e.g., for closed-system intermediates) from certain endpoints, full SIDS data sets are to be provided – wholly independent of exposure considerations.

The need for such complete screening data sets is all the more critical given that EPA is intent on making low-priority designations that preclude, for the foreseeable future, any further data development.  Yet under ChAMP, EPA is routinely making such designations for chemicals that lack the basic SIDS data set.

Acknowledging the limitations

It's very helpful and refreshing that Charlie, as former head of EPA's toxics office, acknowledges that EPA faces high hurdles in trying to mandate testing through issuing TSCA test rules.  That's what many of us have been saying for years, and it's among the strongest arguments for why we so badly need fundamental reform of TSCA.

But even without issuing test rules, EPA could help this situation enormously by forthrightly and transparently identifying and acknowledging the significant gaps and deficiencies in the quality of data remaining for HPV chemicals sponsored under the Challenge.  Instead, Charlie and EPA are papering over the problems through their rhetorical sleight-of-hand of substituting "data gap" with "data need."

Interestingly, Charlie argues that instead of our pressing EPA to pursue test rules, we should just wait for the European Union's REACH Regulation to provide most of the data we need.  As tempting as that sounds, some notes of caution are warranted.  First, for all tests involving laboratory animals, REACH requires only that test proposals, not test results, be submitted at the time of registration.  So even in the best of circumstances, much of the data we need for HPV chemicals likely won't be available for some time after the registration deadline of December 2010.  Second, as I've discussed at length elsewhere, it remains to be seen just how much testing will be required under REACH.

I also appreciate that Charlie has acknowledged the need for major changes in EPA's Inventory Update Rule, given the hugely disappointing results of the latest data collection effort.  I agree with many of his thoughtful proposals for needed fixes.  I'd add another:  Require annual reporting of production and use data.  The current reporting requirement is limited to only a single year once every five years – yielding a highly distorted view of actual chemical production (for more on this, see p. 38 of this paper).

But given the rate at which ChAMP is churning out risk decisions using the current IUR data, I must heartily disagree with his notion that we should set aside concerns about those data and only focus on making improvements for the next IUR collection cycle.  That collection won't even begin until 2011, and if this last round is any guide, data won't be released until 2013 or 2014.  On EPA's current trajectory, ChAMP will have already cranked through all of the HPV chemicals by then.

Bottom line:  ChAMP embodies a blatant double standard

Charlie's responses to date (and the lack of any response from current EPA staff) suggest an unwillingness to engage on the substance of our critique of EPA's ChAMP assessments – its systematic reliance on incomplete and/or poor-quality data, a problem further compounded not only by EPA's refusal to reject such data and identify them as gaps, but its use of such flawed data as a basis to claim no or low toxicity, and thence to draw unwarranted low-risk conclusions about hundreds of HPV chemicals.

All of this brings me to the crux of the problem:  Under ChAMP, EPA appears more than willing to rely on limited hazard, use and exposure data to effectively exonerate scores of chemicals, by relegating them to the low-priority dustbin.  Yet in the few cases where EPA has had to conclude, using the same quality of data, that a chemical poses a high level of concern, no action to control such chemicals is even proposed.

Charlie's characterization of such high-priority chemicals as being only "putative positives" is quite telling.  It's a clear illustration of just how high a bar EPA has set to initiate action to reduce use of or exposure to (or even mandate testing of) a problematic chemical – in contrast to the remarkably low bar it must clear to dismiss a chemical altogether.

That's a double standard I just can't abide.

[Note:  This post was originally posted as a comment on Gina Solomon's blog post on Huffington Post.  The context is a pending budget proposal from the Governor's office in California to eliminate the State's Office of Environmental Health Hazard Assessment (OEHHA) under CalEPA and disperse some but not all of its functions to other agencies.  This proposal, if implemented, would in my view be truly tragic.  If you agree, make your voice heard!] 

As someone intimately involved in chemical assessment and policy both in California and nationally, I find the budget proposal to eliminate or atomize OEHHA to be both deeply disturbing and ironic.

Disturbing, because it would dissolve a world-class group of scientists who for decades have delivered scientifically sound, objective assessments of chemical risks. Losing that top-notch expertise would deprive not just the State, but the globe, of a vital resource.

Ironic, because California is poised to lead the nation in advancing a greener and more sustainable chemicals economy through the Governor's signature Green Chemistry Initiative. Losing OEHHA would rip the heart out of that effort, at the very moment the State most needs an objective source of sound information and expertise to guide critical decisions about chemicals.

Governor Schwarzenegger has expressed understandable reluctance to have the Legislature make risk decisions about chemicals, arguing that a systematic approach driven by agency expertise is needed — hence the Green Chemistry Initiative. While DTSC (lead agency for the Initiative) and other agencies within CalEPA bring much to the table, OEHHA houses the core competency needed to objectively and consistently assess chemicals of concern and potential alternatives.

While California clearly faces major budgetary challenges, the huge return on investment that OEHHA (a tiny agency by any standard) provides to the people of California — by anticipating and reducing the health and environmental impacts of chemicals and their enormous associated costs — more than justifies retaining OEHHA intact within Cal EPA.

As I noted in our first post on ChAMP, after getting off to a strong start in 2007, EPA's abrupt decision in 2008 to steer ChAMP in the direction of cranking out hasty risk decisions was entirely its own.  Can ChAMP be put back on track? 

Neither EPA's own advisory committee – which had many members from the chemical industry as well as a few environmental NGOs – nor the commitment made by the U.S. under the North American Security and Prosperity Partnership (SPP) agreement signed with Canada and Mexico in August 2007, called for such risk assessments or risk-based prioritizations. 

The commitment EPA made under the SPP agreement was "to assess and initiate needed action on the over 9,000 existing chemicals produced above 25,000 lbs/yr in the United States."  There was no mention of risk assessment anywhere in the agreement.  Indeed, at that time, EPA had already begun to publish hazard characterizations, which, as assessments of the hazards of high production volume (HPV) chemicals – fully meet the terms of its SPP commitment.

EPA's focus on developing HPV chemical hazard characterizations was also precisely what it had committed to do when it adopted, in November 2005, the recommendations of its own National Pollution Prevention & Toxics Advisory Committee (NPPTAC).  Specifically, it agreed to complete and make public such hazard characterizations on all HPV chemicals for which it had received final data sets from the HPV Challenge – some 1,200 chemicals – within four years.

How close is EPA to meeting that commitment, with only six months to go?  As of today, EPA has issued only about 130 hazard characterizations covering about 315 HPV chemicals (many of the chemicals are in categories).

So EPA's rush to risk is not only resulting in flawed risk decisions that are prematurely exonerating hundreds of chemicals, as described in our earlier posts.  It is also causing EPA to renege on its promise to characterize the hazards of all sponsored HPV chemicals in a timely manner – and to clearly identify gaps in the quality and completeness of the data received under its voluntary program.

In short, EPA is compromising the public's right to know about the hazards of the most widely used chemicals in U.S. commerce.  That's quite ironic when you consider EPA bills the HPV Challenge and ChAMP as cornerstones of its Chemical Right to Know Initiative.

What should EPA be doing under ChAMP?

EDF is the only environmental NGO that has been willing to engage with EPA, first on the HPV Challenge and more recently on ChAMP.  We served on advisory panels, participated in public meetings, carefully peer-reviewed draft assessments, filed comments and met with EPA staff repeatedly. 

Even now, we are the only voice in our community arguing that the HPV data and ChAMP could provide value if it got back on track.

We have pointed out that many of the shortcomings of the HPV and ChAMP initiatives are due to EPA's limited authority under the Toxic Substances Control Act (TSCA), and we are actively working toward fundamental reform of TSCA to give EPA the tools it needs to do a better job.

But we also believe that in the interim, and despite EPA's constraints under TSCA, EPA can and should be doing a more credible and valuable job under ChAMP. 

EPA should:

• Return the focus of ChAMP to completing high-quality hazard characterizations for HPV chemicals, rather than rushing to issue highly suspect risk characterizations based on flawed assumptions and poor-quality use and exposure information.
• For each chemical assessed, clearly identify and communicate to the public all gaps or quality concerns in available data.
• Stop assigning low-priority rankings to chemicals, especially those with data gaps in the most basic, minimum set of screening-level hazard data. As we said before, it's one thing for EPA to identify as high-hazard those chemicals where, despite the data gaps, available data demonstrate high toxicity. It's quite another for EPA to effectively exonerate chemicals as low-hazard or low-priority when not even a bare-minimum data set is available for them.
• Adopt a health-protective approach to hazard screening: Where data are uncertain, of questionable quality or equivocal, assume a hazard exists until and unless a chemical's manufacturer provides the data to show otherwise.
• Issue test rules to require that gaps in submitted data sets be filled.
• Significantly accelerate issuance of test rules for all of the unsponsored HPV Challenge chemicals, and for the hundreds of newly emerged HPV chemicals that have never been sponsored.
• For the ~4,000 medium-production volume (MPV) chemicals – which are also covered by the SPP commitment, and for which even less data are available than for HPV chemicals – focus on identifying and acting to address data needs to support more robust hazard assessments, rather than pursuing its current approach of using scientifically unsupportable extrapolations of data among loosely defined "clusters" of such chemicals.

For chemicals for which significant hazards are identified, here are some of the good recommendations that NPPTAC offered as steps EPA could take even under its current TSCA authorities, which EPA has yet to act upon (under each, I've added a few elaborations and additional thoughts of my own in brackets):

• Gather additional information on uses (e.g., by use function, category, release potential, or benefit) and exposure (to humans and/or the environment).
  • [Listing such substances on the Toxics Release Inventory would be a great way to get direct exposure data. Efforts to get better use and exposure information - well beyond the data EPA got from manufacturers under its Inventory Update Rule (IUR) - could extend to downstream users of chemicals. Information on functional use would help in identifying safer substitutes within the same functional class.]
• Gather additional information on hazards to support a more in-depth characterization.
  • [Our reviews of EPA's risk decisions have identified many cases where available studies raise more questions than they answer, or identify additional concerns. EPA should require further testing in such cases.]
• Identify existing risk management programs and practices. Evaluate existing Federal and State regulatory controls (e.g., occupational exposure limits).
  • [Instead, in many cases EPA merely asserts the existence or effectiveness of such practices, and seems particularly averse to even suggesting that some risk management might be needed.]
• Provide information referrals or recommendations for actions to other EPA program offices or other Federal or State agencies.
  • [These could include referrals to OSHA requesting action on chemicals posing high worker hazards, proposing that the Centers for Disease Control or the U.S. Geological Survey add such chemicals to their biomonitoring and surface water monitoring programs, referring chemicals to its own Design for Environment (DfE) program to assess the availability and safety of available alternatives to hazardous chemicals, and referring such chemicals to the Food and Drug Administration where they have uses or are in consumer goods that fall under its jurisdiction.]

That's more than enough to keep the EPA toxics office busy for the foreseeable future.

This example raises some new issues as well as some we discussed in the earlier examples:  EPA relies on a highly flawed "category approach" that ignores major differences in the properties and structures of the 13 members of this category.  It compounds this problem by unquestioningly accepting data from inadequate studies to assert low toxicity, rather than demanding that sufficient studies be provided.  As a result, it fails to identify, let alone require to be filled, the enormous gaps in the data available for many of the category members.  EPA ignores or dismisses without explanation its own earlier comments raising serious concerns about the quality and completeness of data provided by the sponsor of these chemicals under the HPV Challenge.  Finally, this example once again shows how EPA's heavy reliance on self-reported use information from manufacturers paints an incomplete and potentially very misleading picture of the actual uses of industrial chemicals. 

The Fatty Nitrogen Derived Cationics category includes 13 chemicals that are used in industrial and consumer detergents and cleaners, as well as hair care products (conditioners or softeners), disinfectants, textile softening and antistatic agents, deodorizers, emulsifiers, dispersants, coagulants, industrial lubricants and corrosion inhibitors, among other uses.  Two supporting chemicals are registered with EPA as antimicrobial pesticides.  Annual production volumes ranged from <1 million pounds for two of the category members to 50-100 million pounds for one of the chemicals.  The sponsor of this group of chemicals under the HPV Challenge was the American Chemistry Council's Fatty Nitrogen Derivatives Panel's Cationics Task Group.

Is this a legitimate category?

EPA and international protocols provide for the grouping of chemicals into categories for data development and assessment purposes.  However, that approach starts with a hypothesis that chemicals that have structural similarities actually possess similar or predictable patterns of biological activity.  These protocols require that the hypothesis actually be demonstrated to be true, once the available data on physical-chemical properties, environmental fate and toxicity/ecotoxicity for the proposed category members are assembled, and that a full and compelling rationale be provided.

Neither the sponsor of this category nor EPA has done any such thing in the present case.  Indeed, the sparse available data do not support the category:

• Few measured physical-chemical and environmental fate data have been provided, which is essential to demonstrate similarity in properties and behavior. Instead, estimated values are provided that are either eerily identical for all category members (e.g., bioconcentration factor, or BCF) or actually vary dramatically across category members (e.g., Henry's Law Constant, which is a measure of the distribution of a chemical between water and the air above it). These findings hardly support the hypothesis that all category members will behave similarly.
• The spotty measured biodegradation data that have been provided also differ significantly (ranging from 0% degradation in 28 days, to 12% in 182 days, to 98% in 2 days). EPA acknowledges this huge range, but fails to discuss how it comports – or doesn't – with the category rationale.
• The aquatic toxicity data vary across category members by orders of magnitude. For example, acute fish toxicity values (96-hour LC50s) vary from 0.07 to 24 milligrams per liter (mg/L) – more than spanning EPA's high-moderate-low hazard classifications.
• Acute oral mammalian toxicity values (LD50s) are available for most category members – but they also vary, from 238 to >16,300 milligrams per kilogram of body weight (mg/kg-bw). And while the sponsor and EPA argue these data are similar enough to support the category (they only span EPA's moderate and low hazard classifications), there is no reason to expect that the mechanisms that impart acute toxicity are at all related to those that lead to other toxicities, such as reproductive or developmental toxicity (these endpoints are discussed further below). So how exactly do similar data for one endpoint support a conclusion that data for entirely unrelated endpoints will be comparably similar? EPA never bothers to explain this.
• As discussed below, far fewer data are available for the other human health endpoints, and what data are available do not support the category.

Despite these findings, EPA states that it agrees with the sponsor's category justification, asserting that the category members possess "similar physicochemical properties, biodegradability, aquatic toxicity, mammalian toxicity and environmental disposition patterns."  The differences in the actual data noted above are neatly set aside.

In comments EPA provided to the sponsor in 2002, EPA itself clearly considered the chemicals in this category to be sufficiently different from each other structurally that it broke them into three subcategories and argued for the need for more data to be provided within the subcategories in order to bolster the overall category.  (As we'll discuss below, the sponsor refused to provide the additional data, and EPA capitulated with nary a word as to why).  These subcategories are:  a) four chemicals that have a single alkyl chain; b) seven that have two alkyl chains; and c) a third subcategory that includes one chemical with three alkyl chains and one that has a dimeric structure.

EPA's rankings 

Now let's look at how EPA ranks the category, and some of the many reasons why we disagree.

Hazard rankings:  EPA ranks the entire chemical category as moderate for human health hazard, apparently due to the results of repeated dose testing.  While EPA maintains that none of the chemicals are expected to bioaccumulate, it expects most (9) of the category members to exhibit moderate persistence.  The hazard for aquatic organisms – fish, invertebrates and algae – is ranked high, based on the results of both acute and chronic testing using multiple test species. 

Exposure rankings:  Exposures to workers, consumers and children are expected by EPA to be high, due to the uses of these chemicals in common household and personal care products.  Releases to the environment are not known, so EPA estimated that exposures to the general public and the environment resulting from such releases would likely be moderate. 

Risk rankings:  EPA judged the risk ranking for this group of chemicals to be medium for all possible receptors. 

Prioritization ranking:  EPA assigned this chemical category a medium priority and identified a list of "possible next steps" to get additional information that would "assist EPA" to develop a better understanding of use and exposures.  These include just about everything you can imagine EPA would have needed to make any findings about exposure in the first place:  potential releases to water from manufacturing, use and disposal; information concerning worker exposures; and information concerning potential exposures to these chemicals in consumer products, such as presence and concentration and consumer use patterns.

Why We Disagree:

1.  As discussed above, the grouping of chemicals into categories can in some cases be justified, but it requires a sufficient amount of measured data to demonstrate that the chemicals within the category actually behave in a similar or predictable manner reflective of their structural similarity. In this case, the available data are grossly insufficient to support the category. Yet EPA still manages to conclude there are no data gaps for any endpoints for this entire category.

     Here is the actual extent of data for the mammalian endpoints:

Endpoint                            # Chemicals with measured data
                                            (includes 2 supporting chemicals)

Acute Oral                                                      11 of 15
Acute Dermal                                                   5 of 15
Acute Inhalation                                              2 of 15
Repeated Dose Oral                                        4 of 15
Repeated Dose Dermal                                    4 of 15
Repeated Dose Inhalation                               0 of 15
Reproductive Toxicity                                       1 of 15
Developmental Toxicity                                    5 of 15

2.  As noted earlier, EPA broke this category into three subcategories, based on structural differences. Let's examine in more detail the nature and extent of mammalian toxicity data provided for the first of these subcategories, the mono alkyl quaternary ammonium chlorides:

a. Repeated dose toxicity. None of the members of this subcategory has a reliable repeated dose toxicity study (a test that is used to evaluate health effects from more than single-dose exposures and serves as a screen for possible effects from chronic exposure). No oral studies are available, and the single dermal study provided used only a single dose. That dose yielded no adverse effects – but the dose was very low, below the dose where if an effect were seen EPA would rank the hazard as high.

Tests that use only a single dose and tests that fail to find an effect level because they use doses that are too low are insufficient to support any hazard assessment.  Yet EPA doesn't even discuss the matter.  It doesn't acknowledge the test is insufficient, nor does it identify this endpoint as a data gap, nor does it adopt a reasonable default assumption in the absence of valid data that developmental toxicity could be high.  Instead, it proceeds merrily to "read across" this negative result to the untested members of the subcategory.  And worst of all, it actually concludes in its hazard characterization summary that "no treatment-related systemic toxicity was evident at the doses tested" – completely burying critical information about data quality and reaching a scientifically unjustified conclusion.

b. Reproductive toxicity. This same subcategory lacks any reproductive toxicity data whatsoever. In comments EPA provided back in 2002 on the test plan submitted by the sponsor of this category, EPA requested that a combined reproductive/ developmental toxicity test be conducted to address this glaring gap (as well as the corresponding gap in data for developmental toxicity). The sponsor responded in 2003, stating that in its view the requested additional testing "will not further the understanding of potential human health hazards…" of these chemicals. The sponsor provided no rationale to support its claim, failing even to acknowledge EPA's point that there were no data available for any of the monoalkyls.

In EPA's current ChAMP assessment, issued in March 2009, EPA now states merely that it accepts this response, and provides absolutely no explanation for its change of heart.  Instead, EPA – without any stated justification – is now content to "read across" to all four members of this subcategory the data from a "supporting" chemical that is actually a di-alkyl, not a mono-alkyl, compound.  Indeed, this supporting chemical serves as the ONLY source of reproductive toxicity test data for all 13 category members!  On this basis, EPA then blithely claims there is no reproductive toxicity – and no data gap for reproductive toxicity – for all 13 members of this category.

c. Developmental toxicity. Data are available for one of the four members of the mono alkyl subcategory for the oral route of exposure, and for two other members for dermal exposure. EPA "reads across" these data to the untested members of the subcategory. That might normally be sufficient, but again in this case neither test yielded any adverse effects at the highest doses tested, and again those doses were very low, below the dose where if an effect were seen EPA would rank the hazard as high.

Remember, tests that fail to find an effect level because they use doses that are too low are insufficient to satisfy an endpoint and support hazard assessment.  But once again, instead of acknowledging this inadequacy, identifying this as a data gap, and using a reasonable default assumption that developmental toxicity could be high, what does EPA do?  It claims "no signs of developmental toxicity were observed"!

In its hazard characterization summary, EPA downplays or omits the results of the developmental toxicity studies it reviewed.  It ignores without explanation evidence of adverse effects that are at least equivocal, and may be significant:

• EPA claims that a test done on the di-alkyl supporting chemical "resulted in no developmental toxicity," despite the fact that increased fetal mortality and decreased fetal body weight were observed – and at doses that warrant a high hazard ranking using EPA's criteria.
• Similarly, with respect to tests done on two dialkyl category chemicals, EPA claims the studies did not produce an effect at the highest doses tested. Yet both chemicals were actually found to have increased fetal resorptions, albeit at doses that EPA would rank as low-hazard.

In each of these cases, we are forced to infer a rationale because EPA never clearly explains its decisions.  But the apparent rationales – effects seen only at doses that are also toxic to the mother, effects within the range historically observed for controls in the laboratory (though with no supporting data provided by the laboratory) – are not sufficient to conclude there are no adverse developmental effects, even if they are also insufficient to conclude there are such effects.  Indeed, in a screening-level hazard characterization based on scant or equivocal data, the default should be either to assume an effect exists or at the very least to call for further testing.

Finally, even if one were to accept these studies as definitively negative for the dialkyl subcategory, EPA has no basis either to extrapolate that finding to the other subcategories or to paper over the enormous data gap that exists for this endpoint.

3. We also disagree with EPA's risk ranking for this chemical category. Even assuming EPA's moderate ranking of the human health hazard of this group is appropriate, given that there remain important data gaps, and exposures to humans are ranked high, and the chemicals are likely to be washed down the drain into the environment, we don't see how this category should be ranked as anything but both high risk and high priority.

4. The two supporting chemicals used to provide hazard data for this category are both antimicrobials, and given EPA's readiness to treat all of the chemicals together, it is reasonable to assume that the category chemicals may also have antimicrobial properties. Add to this the facts that the chemicals in this category are used in a widespread and dispersive manner, and that they may well end up in wastewater treatment plants and surface waters, there is every reason to be concerned that they could adversely affect beneficial microbes used in wastewater treatment and found in the environment.

Antimicrobials used and marketed as such are exempted from TSCA, and are instead regulated under the Federal Insecticide, Fungicide and Rodenticide Act.  However, the chemicals in this category are used in applications where such a function and associated claims are not operative. That is, we have a group of chemicals that EPA considers similar to known antimicrobial pesticides that are disposed of down the drain, into sewage treatment systems that may not effectively remove these chemicals, potentially resulting in distribution through the ecosystem.

EPA is wholly silent on this issue.  In addition to collecting more data, we would strongly recommend that these chemicals be evaluated to determine if inherent antimicrobial properties warrant regulation as antimicrobial pesticides.

5. EPA ranks most (9) of the category members as exhibiting moderate persistence, and the remaining four as of low persistence. Yet it barely discusses the available data and ignores the following:

• Using EPA's own criteria, 3 of the 4 chemicals EPA ranked low actually exhibit moderate photodegradation rates (based on estimated data, as no measured data were provided).
• 3 of the 4 chemicals EPA ranked low for biodegradation appear to exceed EPA's criterion for a low ranking, and several of those ranked moderate show little if any biodegradation.
• EPA ranks as moderate one chemical that showed 0% degradation in 28 days. This obviously should be ranked high.
• EPA also ranks as moderate another chemical that has a half-life in soil of a whopping 1,048 days – nearly 3 years! EPA's criteria rank any half-life in soil that exceeds 180 days as high – yet EPA's ranking of this chemical is, inexplicably, moderate.
• 6 of the category members have no biodegradation data, and any rationale for EPA's implied read-across from the other members is absent.

In comments EPA provided earlier to the sponsor, EPA raised several serious concerns about the extent and nature of data provided for, and the sponsor's claims made about, biodegradation.  In the sponsor's response, it refused to do the testing EPA called for or to revise its claims that all category members are biodegradable. 

In its current ChAMP assessment, EPA seems once again to have fully capitulated:  no data gaps identified, no flagging of the enormous range in biodegradation values that calls into question the viability of the category, and a failure in contradiction of its own criteria to identify any of the category members as having high persistence.

6. EPA claims that none of the category members are expected to bioaccumulate. This is based, however, entirely on estimated data using an EPA model that yields the exact same result – a bioconcentration factor estimate of 71 – for all 13 category members. Doesn't this bear some explanation? Why can't this parameter be measured? EPA's silence is deafening.

7. Last, but not least, this ChAMP assessment amply illustrates the huge shortcomings of the use information EPA has sought to collect under its Inventory Update Rule (IUR). As we've discussed at length before, these data are of questionable value because they are self-reported by manufacturers, often incomplete because of major reporting loopholes EPA has provided, and often kept removed from any public access because EPA provides wide latitude for submitters to claim the information to be confidential. This category is a great example of these problems.

IUR submissions were received for 11 of the 13 category members.  Here's a summary of the extent of data EPA did and did not receive, and what it has not made public because of confidential business information (CBI) claims:

Types of responses in IUR submissions
Number of chemicals

*  Submitter did not submit because information is "not readily obtainable"
** Number represents CBI submissions identified as such by EPA.  EPA notes the number could be higher.

In this case, EPA has ready access to other public sources of use information for these chemicals – including, ironically, the HPV Challenge submission for this category that was provided by the same companies that under the IUR claimed such information CBI!  But in other cases, such information may not be available, as reliable and current chemical use information is very limited in general.

Given the poor performance of manufacturers reporting under the IUR, and the often very limited availability of information from other sources, how comfortable are you in EPA using these data to assess chemicals' risks to workers, the public, the environment, consumers and children?

Conclusion

In an earlier post, we characterized EPA as constructing "houses of cards" in its ChAMP assessments.  Some of you might have considered that to be awfully harsh.

But here's a classic house of cards:  EPA uses very spotty, variable, misclassified or entirely estimated data on degradation or bioconcentration to claim that this questionable category of chemicals has only low or moderate environmental persistence and bioaccumulation potential.  It then uses those findings to downgrade use information that clearly indicates these chemicals are used in a manner that culminates in down-the-drain disposal or similar release, and hence significant, ubiquitous releases to the environment – in order to claim that exposures to aquatic organisms and the general population via such releases will only be "medium."  Finally, it uses that finding to downgrade its finding of high aquatic hazard to a medium risk ranking, and to further downplay its (flawed) moderate human health hazard by finding only a medium risk to the general population.

Any questions?

Our analysis of EPA's risk decision under ChAMP for this category of toxic chemicals vividly illustrates how EPA has failed to adopt a health-protective approach to its screening of HPV chemicals.  Rather, it misclassifies or understates these chemicals' hazards, asserts that existing regulations are sufficient even when they are quite old or do not cover identified exposures, and naively assumes that children will not be as exposed as adults to consumer products used in the home unless they are intended for their use.  Finally, this case demonstrates that manufacturers are not reporting to EPA even readily available information on their chemicals' uses. 

The chlorobenzenes category is comprised of four chemicals: monochlorobenzene (CAS# 108-90-7), 1,2-dichlorobenzene (CAS# 95-50-1), 1,3-dichlorobenzene (CAS# 541-73-1) and 1,2,3-trichlorobenzene (CAS# 87-61-6).  The first three of these chemicals are on the Toxics Release Inventory (TRI).  Reported production volumes under the Inventory Update Rule and TRI emissions for 2005 and reporting manufacturers (other companies may have claimed their identity to be confidential business information) for these chemicals are as follows:

Industrial uses reported by manufacturers include use as intermediates and solvents for plastics manufacturing and basic organic chemicals manufacturing, and pesticide and other agricultural chemical manufacturing.  EPA notes other uses cited in the Hazardous Substances Data Bank (HSDB):  "pesticides, solvents, heat transfer medium, and chemical intermediates, as well as many other uses."

All members of this category were included in test rules issued under TSCA Section 4, in use and exposure-related information reporting rules issued under TSCA section 8(a), and health and safety data reporting rules issued under TSCA section 8(d).  Additionally, these chemicals are regulated under the Clean Air Act and Clean Water Act, and the Occupational Safety and Health Administration (OSHA) has set Permissible Exposure Limits (PELs) for two of the chemicals (1,2-dichlorobenzene and monochlorobenzene).

EPA considers 1,3-dichlorobenzene to be a high-priority chemical, a decision with which we agree (but see point 8 below).  It considers the other chemicals to be low-priority, and this review primarily focuses on that decision.

Hazard rankings:  EPA ranks monochlorobenzene, 1,2-dichlorobenzene and 1,2,3-trichlorobenzene as having moderate human health hazard, based on the results of repeated dose toxicity tests and developmental toxicity tests.  All three of these chemicals (as well as 1,3-dichlorobenzene and one of the supporting chemicals for the category) exhibited evidence of genotoxicity in vivo. One of the chemicals (monochlorobenzene) exhibited some, though not clear, evidence of carcinogenicity, and one of the supporting chemicals showed clear evidence of carcinogenicity.

Exposure rankings:  EPA indicates that there is a high potential for exposure to these chemicals of the general public via environmental releases, based on their reported TRI releases, environmental persistence, detection in environmental monitoring and their myriad uses.  EPA ranks worker exposures high (for two chemicals) and moderate (for the third).  Based on the use of these chemicals in consumer products, EPA ranks exposures to consumers as high and exposures to children as medium.  Interestingly, EPA reports that the IUR data – submitted by manufacturers – do not indicate uses in consumer products, but that several other sources, including the HSDB, the NIH Household Products Database, and EPA's Source Ranking Database, do indicate uses in consumer products.

Risk rankings:  EPA ranks the risks of these three chemicals to the environment to be moderate to fish and high to invertebrates and aquatic plants.  It ranks risks to the general public, consumer and children as moderate, despite their high exposure potential, based on ranking human health hazard as moderate.  EPA ranks risks to workers as low for the two chemicals with OSHA PELs (1,2-dichlorobenzene and monochlorobenzene) and moderate for 1,2,3-trichlorobenzene.

Prioritization rankings:  EPA considers all three chemicals to be low-priority because it expects existing regulations and ongoing reporting to be sufficient to mitigate risk and to alert EPA to the presence of chemicals in workplaces, environmental releases from facilities, and drinking water.

Why we disagree:

1. Given the high exposure potential to these chemicals, which EPA found to pose moderate human health hazards, even a modestly health-protective decision would rank their risks to the general public, consumers and children as high, not moderate. The potentially large number of uses, the large production volumes and TRI releases for two of the three chemicals and the substantial uncertainty regarding the magnitude, frequency, and duration of possible exposures, would support such a ranking.
        In this way, at least the development of better hazard, use and exposure information and further scrutiny of the magnitude of risks would be spurred.  Instead, EPA concludes that "No follow-up action is suggested at this time on [these three] chemicals in this category.
2. The conclusion that these chemicals are low-priority due to the existence of Clean Air Act and Clean Water Act regulations is unjustified. Despite those regulations, substantial TRI releases to air and some releases to water are being reported – sufficient for EPA to rank exposure potential as high. Yet EPA then invokes those same regulations as being adequate to prevent the very exposures it just characterized as potentially high!
3. The main reason EPA ranked consumers' and children's exposure potential high and medium, respectively, is because of expected exposures through consumer products. However, the cited CAA and CWA regulations do not address these exposures at all.
4. EPA provides no real basis for ranking children's risks lower than consumers'. EPA implies this is because it lacks evidence that these chemicals are used in products specifically intended for use by children. But EPA notes it sources of use information indicate "many other uses" for these chemicals that are not identified, and EPA provides no basis on which to conclude that uses in products not intended for use by children would not expose them. Indeed, EPA acknowledges: "Exposures to children, however, may be expected to occur through the household use of some consumer products" (p. 48 here).
5. Positive results for all of the chemicals in this category in in vivo genotoxicity studies, and for monochlorobenzene and one of the supporting chemicals in two-year carcinogenicity bioassays, clearly warrant follow-on testing to clarify the carcinogenic potential of at least the untested chemicals in this category. Yet EPA proposes no such testing; indeed it barely discusses the findings other than to repeatedly emphasize the one chemical for which negative carcinogenicity results were found.
6. In its risk rationale for children, EPA misclassifies the level of developmental toxicity for two of the three chemicals. On p. 3 here, EPA claims "available data with postnatal exposures in animals suggest a low hazard for two category members (CASRNs 95-50-1 and 108-90-7)." Yet the results of developmental toxicity tests in rats via inhalation exposure to vapors of these two chemicals actually showed moderate and high developmental toxicity, respectively, based on EPA's own criteria:
   • CAS# 95-50-1:  LOAEL ~ 2.4 mg/L/day vs. EPA range for moderate developmental toxicity of 1-2.5 mg/L/day (see pp. 27 and 38 here vs. the table on p. 12 of EPA's Methodology for Risk-Based Prioritizations under ChAMP.
   • CAS# 108-90-7:  LOAEL ~ 0.35 mg/L/day vs. EPA cutoff for high developmental toxicity of <1.0 mg/L/day (see pp. 26 and 38 here vs. the table on p. 12 of EPA's Methodology for Risk-Based Prioritizations under ChAMP
     High exposure and high or moderate developmental toxicity – surely even EPA will acknowledge these chemicals merit a high-risk and high-priority ranking?
7. EPA invokes the existence of OSHA PELs for two of these chemicals to argue that worker risk is low. Both of these PELs were promulgated in 1989 (see here and here), and at least for one of them, monochlorobenzene, NIOSH has found that "[t]he 1989 OSHA PEL may not be protective to workers."
        Were these PELs developed in consideration of and are they adequate to protect against the toxicities EPA presents herein?  While some of the test data (ca. 1984, 1987) predate the year the PELs were adopted, given the long process required to develop a PEL, the timing cannot be taken as evidence that such data were considered by OSHA.  EPA cannot merely assert that the PELs are adequate to protect workers without demonstrating that the permissible levels were set after evaluation of these data, and are still adequate in light of any other more recent toxicity data. 
        At the very least, EPA needs to engage in a meaningful referral of these data to OSHA, using its TSCA Section 9 authority, including follow-up to ensure the data have been fully considered and acted upon appropriately at OSHA.
8. Despite its high-priority finding for one of the chemicals in this category, 1,3-dichlorobenzene, EPA's only response is to state that "in order to confirm or refute the high potential risk … companies are encouraged to provide available information on a voluntary and non-confidential basis." This is clearly inadequate for such a high-risk chemical. It begs the question: what would it take for EPA to be willing to actually impose risk management on such a chemical?
9. Last but not least, EPA's finding that there are myriad product uses of these chemicals – none of which were reported by any of their manufacturers under the Inventory Update Rule (IUR) – vividly illustrates why EPA's frequent sole or primary reliance on the IUR as its source of use and exposure data for ChAMP assessments is wholly inadequate as a basis for making exposure and risk decisions for high production volume chemicals.

This post is the first of a number to come that will examine in some detail specific chemicals and chemical categories for which EPA has made questionable or flawed risk decisions under ChAMP. Many of these problems can be traced to EPA's near-exclusive reliance on incomplete or poor-quality data provided by manufacturers, or its need to resort to unsupported assumptions in the absence of sufficient data. For each posting, we'll summarize what is known about production and use of the chemical(s); describe EPA's hazard, exposure, risk and priority rankings; and then discuss why we question or disagree with EPA's decisions. First up: a category of three alkyl nitriles.

The alkyl nitriles category is comprised of three chemicals: propionitrile (CAS# 107-12-0), butyronitrile (CAS# 109-74-0), and isobutyronitrile (CAS# 78-82-0). Their annual production volumes range from 3 to 30 million pounds. EPA's 2006 Inventory Update Rule data list a single producer for each chemical; other companies may have claimed their identity to be confidential business information (CBI):

According to EPA based on data supplied by their manufacturers, these chemicals are used primarily as chemical intermediates in the manufacture of insecticides, other industrial chemicals and pharmaceuticals. However, other industrial uses as catalysts, dielectric fluids and solvents were also reported, as well as possible use of one of the chemicals as a gasoline additive. EPA states that no commercial or consumer uses of these chemicals have been reported by their manufacturers. Two of the chemicals, propionitrile and isobutyronitrile, are regulated as Extremely Hazardous Substances under the Clean Air Act.

Hazard rankings: Although these chemicals are not persistent or bioaccumulative, EPA found that they are toxic following repeated dosing and can cause developmental defects. As a result, EPA classified these chemicals as highly hazardous to human health. In contrast, EPA ranked these chemicals as low hazard to aquatic organisms, based on testing results in fish, invertebrates and aquatic plants submitted by the manufacturers.

Exposure rankings: EPA concludes that environmental exposures will be low even if there are releases, because the chemicals would rapidly break down. Information submitted by manufacturers under EPA's Inventory Update Rule (IUR) did not indicate any commercial or consumer uses, including in products intended for use by children. EPA relies on this information to conclude that exposures to consumers and children are low. Other evidence beyond the IUR suggesting uses in pharmaceuticals and gasoline is not considered by EPA in making these rankings. EPA ranks worker exposure potential as high, as these are volatile chemicals that could readily partition to air, if not contained.

Risk rankings: Despite the high hazard ranking, EPA's risk conclusions emphasize the anticipated low exposure to characterize human health risks for the general public, consumers and children as low. EPA ranks the potential risk to workers as high.

Prioritization ranking: Despite finding both high human health hazard and high potential exposures and therefore risks to workers, EPA considers the alkyl nitriles category to be of low priority. EPA bases this ranking primarily on the existence of a National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit (REL), which EPA claims if implemented would manage risks to workers.

Why We Disagree:

1. EPA has no basis to assume that the mere existence of the NIOSH recommended exposure limit for one of these chemicals means that it is being used or complied with. The REL is not a regulatory standard and EPA provides no empirical evidence whatsoever to indicate the extent to which it is being met in workplaces handling these chemicals. EPA itself states the reason why RELs should not be considered in ranking exposure: "these limits are not enforceable" (emphasis added; see p. 16 of EPA's Methodology for Risk-Based Prioritization Under ChAMP). Yet it then proceeds to reduce the priority of a category of highly hazardous chemicals to low on that very basis!

Likewise, EPA invokes the mere existence of a NIOSH/International Program on Chemical Safety (IPCS) International Chemical Safety Card for a second of the three chemicals and a NIOSH recommendation for establishing a workplace exposure standard for nitriles – a recommendation issued in 1978 that has never been acted on by OSHA! – as justification its low-priority ranking.

2. While we agree that the human health hazard posed by alkyl nitriles is high, we question EPA's low ranking for eco-hazard. Readily available data not referenced by EPA, which we quickly found via a simple Google search, indicates that both NIOSH and the International Program on Chemical Safety (IPCS) indicates that at least two of these chemicals may be ecotoxic: one may be hazardous to birds (butyronitrile), and another to aquatic organisms (proprionitrile).

In contrast, EPA appears to have relied solely on data submitted by the manufacturers of these chemicals, despite the fact that IPCS is listed as one of the supplemental sources EPA claims to search for hazard data (see Appendix B of EPA's Methodology document). For at least one of these chemicals, proprionitrile, EPA clearly knew of the existence of the IPCS document – because it (selectively) cited its mere existence as a basis for its low-priority ranking (see point 1 above).

The extent of ecological hazard is an issue that needs to be resolved, not ignored as will result from EPA's low-priority ranking for these chemicals.

3. EPA gives too much credence to the unsubstantiated use and exposure information provided by manufacturers. For two of the three chemicals, EPA has publicly provided a description of the industrial processing information supplied by the manufacturer under the IUR; for the third, that information was provided to EPA but claimed to be confidential. By accepting the limited use information provided under the IUR at face value, EPA assumes that 100% of production goes into use as intermediates. Yet EPA cites evidence from other sources suggesting other uses of these chemicals.

4. EPA bases most of its low-exposure findings on the fact that alkyl nitriles are used primarily as intermediates to make other industrial chemicals as well as pesticides and pharmaceuticals. Yet EPA fails to provide any data or even to discuss the potential for the final products to contain unreacted starting chemical (termed "residual" though the amounts can be significant). If present, the final product could be a source of exposure to the starting chemical.

While industrial chemical products made using alkyl nitriles are regulated under TSCA, EPA points out that pharmaceutical and pesticide products are not. Regardless, all sources of exposure to TSCA-regulated chemicals used as intermediates – including via residuals present in products – need to be considered. There is no mention of the nature of the products produced or how they are used. Exposure potential to such residuals in pharmaceuticals is obvious. For pesticides, worker and environmental exposures can be expected, and if approved for residential use, consumers applying the pesticides and children playing nearby could be exposed as well.

Exposure to residuals of the highly hazardous alkyl nitriles in products may or may not be significant, but EPA's silence on this question effectively means it has simply ignored it and assumed that there will be no or low exposure via this route. And its final prioritization decision relegating this chemical to low priority effectively closes the book on such questions.

5. EPA uses its exceedingly weak exposure characterization to justify the decision to assign low human health risk rankings for the general public, consumers, and children. This could readily result in underestimating risk, rather than taking a health-protective approach, which is the appropriate outcome of a screening-level risk characterization.

As a consequence of the hasty risk decisions made by EPA, important questions regarding the actual risks posed by these chemicals will not be answered: Could environmental organisms really be harmed? Are there residual levels of these chemicals in consumer products? Are workers adequately protected?