Richard Denison, Ph.D., is a Lead Senior Scientist.
Yesterday EDF submitted comments on a supplement to EPA’s 1,4-dioxane risk evaluation under the Toxic Substances Control Act (TSCA), which the agency issued a scant three weeks ago.
This solvent is a likely human carcinogen that contaminates drinking water nationwide and is present in millions of consumer products.[pullquote]What EPA left out of its analysis swallows what it included.[/pullquote]
The supplement expands the scope of EPA’s ongoing risk evaluation of 1,4-dioxane. It now includes certain water exposures and certain exposures of consumers to products in which the chemical is present as a contaminant (more technically, a “byproduct”).
EPA rushed the public comment period, providing only 20 days and refusing requests from at least 14 organizations for an extension. The agency also cut out another vital step in the process – peer review –in violation of its own rules for how risk evaluations are to be conducted.
But that wasn’t the only thing EPA rushed. The Supplement itself was an 11th-hour affair, done mainly to appease a hypocritical demand from the formulated chemical products industry.
The haste with which it was assembled badly shows. The additional exposures EPA examined are so narrowly constructed as to omit major, and potentially the largest, sources of exposure and risk people face from the presence of 1,4-dioxane in water and products.
And what EPA left out of its analysis swallows what it included.
Omissions of key water-related exposures
EPA’s expansion of its analysis of water-related exposures includes only people’s direct exposures from swimming and indirect exposures from fish consumption. EPA continues to ignore the big kahuna – drinking water exposures.
EPA’s rationale for now including swimming and eating fish is its belated acknowledgment that 1,4-dioxane lacks a water quality criterion for human health under the Clean Water Act, and hence it decided it couldn’t get away with deferring to that law to avoid addressing those exposures.
But here’s the rub: That rationale should apply equally to drinking water, as 1,4-dioxane lacks any national standard under the Safe Drinking Water Act. Yet EPA perpetuates this blatant contradiction by continuing to exclude drinking water exposures, which are chronic in nature, from its risk evaluation.
EPA also excludes other obvious sources and routes of water exposure, including:
- releases of the chemical in wastewater from residential or commercial use of products containing 1,4-dioxane as a byproduct;
- exposures during bathing, showering and cooking in water (hot or warm) containing 1,4-dioxane;
- releases associated with oil and gas production – the chemical is used in hydraulic fracturing and contaminates the wastewaters that are generated.
Omissions of key product-related exposures
EPA’s expansion to include direct consumer exposure to certain products in which 1,4-dioxane is present as a byproduct is equally narrow and selective. EPA first acknowledges that the chemical contaminates industrial, commercial, and consumer products. But in the very next sentence, EPA entirely ignores the former two.
That means it also ignores the millions of workers exposed during the manufacture, use or disposal of those industrial and commercial products. This includes people working in industrial laundries and car washes; in building maintenance, housekeeping, painting or automotive services; or as insulation installers or in construction jobs.
All of these workers can be expected to be more highly and chronically exposed than the consumers EPA does include, because they use such products more frequently, for many more hours each day, and/or in higher-strength formulations than do consumers.
EPA also ignores the enormous volumes of wastewater containing 1,4-dioxane discharged from the above activities.
Omissions of disproportionately impacted groups
EPA has failed to analyze those groups that face greater risk due to greater susceptibility or greater exposure, including children, workers and communities near sources of release of 1,4-dioxane. This – despite TSCA’s mandate that EPA identify and evaluate potential risks to “potentially exposed or susceptible subpopulations.”
Omissions of combined exposures
EPA also entirely ignored the obvious fact that people are exposed to this chemical from multiple sources. Instead EPA looked at each exposure in isolation from each other exposure. Here are a few examples of what EPA’s myopic approach misses:
- A consumer using more than one product containing 1,4-dioxane each day (e.g., washing a load of clothes and cleaning a kitchen or bathroom surface).
- A worker exposed at work and also as a consumer at home through product use.
- A worker or consumer exposed both dermally and via inhalation simultaneously from the same product use or sequentially even in the short term through different product use.
- A resident of a community near a facility releasing 1,4-dioxane, who also uses products at home and drinks water contaminated with the chemical.
As the saying goes, haste makes waste.