Non-Cancer Science Assessment For Dioxins Finalized

U.S. Environmental Protection Agency (EPA) has finalized its non-cancer science assessment for dioxins, which was last reviewed in the 1980s. Dioxins are toxic chemicals that naturally exist in the environment and can be released into the environment through forest fires, backyard burning of trash, certain industrial activities, and residue from past commercial burning of waste. The assessment findings show that generally, over a person’s lifetime, current exposure to dioxins does not pose a significant health risk.

EPA has identified many known sources of dioxins. Working with other federal agencies, such as the U.S. Department of Health and Human Services and the U.S. Department of Agriculture, EPA has taken steps to address dioxin. This includes research on dioxin exposure and effects; assessing dioxin human health risks; measuring dioxin levels in the environment; and reducing exposure to dioxin.

The non-cancer health assessment for dioxin could be considered in a range of agency activities, from establishing cleanup levels at Superfund sites, to reviewing the dioxin drinking water standard as part of EPA’s regularly scheduled review process, to evaluating whether additional Clean Air Act limits on dioxin emissions are warranted.

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address Environmental Review and Environmental Impact Assessment.

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Final Health Assessment For Tetrachloroethylene (Perc) Released

U.S. Environmental Protection Agency (EPA) has released the final health assessment for tetrachloroethylene (also known as perchloroethylene, or perc) to EPA’s Integrated Risk Information System (IRIS) database. The assessment replaces the 1988 IRIS assessment for perc and for the first time includes a hazard characterization for cancer effects. Perc is a chemical solvent widely used in the dry cleaning industry. It is also used in the cleaning of metal machinery and to manufacture some consumer products and other chemicals. The final assessment characterizes perc as a “likely human carcinogen.” The assessment provides estimates for both cancer and non-cancer effects associated with exposure to perc over a lifetime.

EPA did not believe that wearing clothes dry cleaned with perc will result in exposures which pose a risk of concern. EPA has already taken several actions to reduce exposure to perc. EPA has clean air standards for dry cleaners that use perc, including requirements that will phase-out the use of perc by dry cleaners in residential buildings by December 21, 2020. EPA also set limits for perc allowed in drinking water and levels for cleaning up perc at Superfund sites throughout the country, which will be updated in light of the final IRIS assessment.

In the future, the toxicity values reported in the perc IRIS assessment will be considered in:

• Establishing cleanup levels at Superfund sites where perc is a contaminant,
• Revising EPA’s Maximum Contaminant Level (MCL) for perc in drinking water, and
• Evaluating whether to propose additional limits on air emissions of perc.

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address Environmental Review and Environmental Impact Assessment.

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