On June 25, 2018, the U.S. Environmental Protection Agency (EPA) held a preparatory meeting for experts selected to serve as letter peer reviewers for EPA's Exposure and Use Assessment and Human Health and Environmental Hazard Summary for five persistent, bioaccumulative, and toxic (PBT) chemicals. A list of those chemicals is available here. Although the meeting was scheduled for four hours, it adjourned after only two hours, as there were only a few questions from peer reviewers and only two outside stakeholders providing oral comments. Below are some highlights/takeaways from the meeting:
- All five PBT chemicals being reviewed scored high for hazard;
- Two PBT chemicals were pulled from EPA action under the Toxic Substances Control Act (TSCA) Section 6 because manufacturers requested risk evaluations for them prior to the September 19, 2016, deadline;
- Four of the PBT chemicals scored high or moderate for exposure; one scored low (pentachlorothiophenol (PCTP));
- For exposure assessment, EPA split up information as “core exposure data” or “supplemental exposure data”: core exposure data would be environmental data, monitoring, biomonitoring, modeled concentrations, or modeled dose; and supplemental exposure data would be environmental fate, engineering data, or other information related to exposure information or pathways;
- EPA identified exposure scenarios -- looking at source/use, environmental pathways, and receptors;
- EPA did not conduct any new modeling on the chemicals but did use modeled data from published literature;
- EPA did not conduct an exhaustive literature search, review, or assessment of hazard data, it used data readily available, as described in the Human Health and Environmental Hazard Summary; the EPA document “Supplemental Information for the Exposure and Use Assessment of Five Persistent, Bioaccumulative and Toxic Chemicals” outlines the literature search process used for exposure data; and
- Exposure scenarios include both quantitative and qualitative information.
No written comments were submitted prior to the peer review webinar. Only three people signed up for oral comments, and one was not present online. The two public commenters noted concerns regarding the likelihood of exposure, including the potential for accidental exposures; the lack of EPA focus on susceptible subpopulations; EPA’s intent not to address exposures that are already regulated under other EPA programs; and the need to assess the risk of bias.
Per the language in amended TSCA, EPA must issue risk management proposals to reduce exposures to the extent practicable by June 19, 2019.
Any public comments submitted by July 23, 2018, will be shared with peer reviewers. Comments submitted between July 23, 2018, and August 17, 2018, will be available to EPA for consideration. All comments are due by August 17, 2018. A recording of the webinar, slides, and other materials from the meeting will be posted in Docket EPA-HQ-OPPT-2018-0314. There are currently six supporting documents posted:
- Environmental and Human Health Hazards of Five Persistent, Bioaccumulative and Toxic Chemicals;
- Exposure and Use Assessment Peer Review Charge Questions;
- Environmental and Human Health Hazard Summary Peer Review Charge Questions;
- Supplemental Information for the Exposure and Use Assessment of Five Persistent, Bioaccumulative and Toxic Chemicals;
- Transmission of Background Materials and Charge to the Panel for the TSCA Letter Peer Review Reviewing Exposure and Use Assessment and Ecological and Human Health Summary for Five PBT chemicals; and
- Exposure and Use Assessment of Five Persistent, Bioaccumulative and Toxic Chemicals.