Lindsay McCormick is a Research Analyst.
Until June 2014, EPA had not completed a chemical risk assessment under its Toxic Substances Control Act (TSCA) authority in 28 years. Since then, EPA seems to have been somewhat picking up the pace: Over the past year and a half EPA has completed four additional risk assessments through the TSCA Work Plan Chemical Program, which is designed to assess the risks of priority chemicals currently on the market.
Recently, EPA initiated its assessment process for the next set of Work Plan chemicals, including three “clusters” of flame retardant chemicals. We fully support EPA’s current efforts to assess the risks of these flame retardants – with the end goal of managing identified risks – and have provided quite extensive comments on EPA’s initial scoping documents. In this post, I’ll highlight some of our comments and recommendations; see the links at the end to access the comments themselves.
This summer, EPA published initial scoping documents on three clusters of structurally similar flame retardant chemicals: Chlorinated Phosphate Esters (CPE), Cyclic Aliphatic Bromides (HBCD), and Tetrabromobisphenol A (TBBPA) and related chemicals.
As an earlier generation of flame retardants, the polybrominated diphenyl ethers (PBDEs), have been phased out of the market due to rising concerns over their health effects (such as their impact on brain development), other, less studied, flame retardants have swept in to take their place. Today, CPEs are widely used in paints, textiles, insulation, and polyurethane foam, HBCD in thermal insulation boards and other building materials, and TBBPA in electronic products such as computers and remote controls.
However, new research is increasingly linking these replacement flame retardants to health impacts as well – including cancer and reproductive effects. Some of these chemicals have been evaluated (and regulated) by other countries. For example, the use of Tris(2-chloroethyl)phosphate (TCEP), a CPE cluster chemical, has been regulated in the EU under its REACH regulation.
The potential risks posed by these flame retardants certainly warrant EPA’s attention, given the breadth of their use and emerging scientific research findings. However, judging from the scoping documents, EPA intends to conduct narrowly focused risk assessments – excluding major uses, pathways and routes of exposure, potentially relevant health effects, and certain potentially highly exposed populations.
Limited scope and inadequate justifications
The assessments for all three clusters, for example, will focus entirely on oral exposures. This means that exposures to these chemicals from breathing in contaminated air (inhalation exposure) or from directly touching these chemicals or products made with them (dermal exposure) will not be factored into the analysis. For the CPE cluster chemicals, exposure to worker populations (which is expected to occur primarily through inhalation and dermal routes of exposure), will be excluded entirely from the assessment. Furthermore, many chemicals in the initially identified clusters are being dropped altogether. These omissions are largely due to the lack of sufficient information to support a quantitative risk assessment of the chemicals or pathways.
In our comments, we argue that the limited scopes proposed by EPA are bound to result in risk assessments that dramatically underestimate risks from these chemicals, and we urge EPA to make that clear. Our concerns are broader, however, and extend to the inadequacy, inconsistency and lack of clarity of the justifications EPA provides for these exclusions.
For example, in justifying why it has excluded specific exposure scenarios and/or cluster chemicals from further assessment, the Agency frequently conflates or fails to distinguish between its expectation of low risk potential versus the insufficiency of data needed to conduct a risk assessment. Clearly differentiating between these two explanations for any exclusions, we argue, is essential: Just because data are limited does not mean that no or low risk can be concluded. Blurring these lines may make it more difficult for EPA to justify revisiting excluded scenarios when it has better data in the future, by inadvertently providing unwarranted arguments to stakeholder groups seeking to limit further review and risk management of their chemicals.
EPA has generally excluded food as a route of exposure from these assessments. Its rationale – that it is the “purview of other federal agencies” – also leaves a lot to be desired. It is not only inconsistent with the Agency’s decision to include a quantitative assessment of exposures via fish consumption for all three flame retardant clusters, but also with the Agency’s history of addressing food as a route of exposure, as demonstrated in its science and policy statements (see, for example, EPA’s research on consumption of rice contaminated with arsenic, workshop on infant consumption of contaminated breast milk, and Exposure Assessment Tool Box (“Expobox”) description of lifecycle impacts of chemicals on the food supply).
Excluding food additives, which clearly fall under FDA’s jurisdiction, from the scope of the assessments is understandable. However, it is inappropriate for EPA to exclude food as a vector for exposure on the basis that it is the purview of other agencies, given that contamination of food may derive from uses of a chemical that fall under TSCA’s jurisdiction.
A balancing act
We also argue that EPA must thoughtfully balance the dual importance of using robust science and striving for comprehensive assessments on the one hand, and timely decision-making on the other. The limited scopes proposed by EPA are not surprising, given resource constraints, major data gaps regarding the toxicity of and exposure to some of these flame retardants, and EPA’s limited authority to address these data gaps in a timely manner.
In light of these realities, EDF encourages EPA to take a two-pronged approach, both with the present assessments and future Work Plan chemical assessments:
- Move forward swiftly with completing risk assessments in (relatively) data-rich areas and with taking regulatory actions to address identified risks.
- Fully acknowledge the limited scope of and exclusions from these assessments; actively take steps to fill data gaps in data-poor areas; and revisit and expand the scopes of the assessments as new data become available.
Moving forward where possible now, while acknowledging and taking steps to address data gaps to enable more complete assessments in the future, seems to us to be the right recipe.