EPA Identifies Seven Initial Work Plan Chemicals for 2012 Risk Assessment
Yesterday, the U.S. Environmental Protection Agency's ("EPA") Office of Pollution Prevention and Toxics released two documents, "TSCA Work Plan Chemicals: Methods Development" and "Existing Chemicals Program: Strategy." These documents describe the first set of chemicals or categories ("Work Plan Chemicals") for which EPA plans to develop risk assessments and evaluate risk management actions. Among 1,235 chemicals considered, 83 were identified for review with seven being listed for assessment in 2012. Companies involved in the production or use of these chemicals should take particular note of several important concerns.
Initial Set of Work Plan Chemicals/Categories for 2012 Risk Assessments
- Antimony and Antimony compounds
- 1,3,4,6,7,8-Hexahydro4,6,6,7,8,8,-hexamethylcyclopenta [g]-2-benzopyran (HHCB)
- Long-chain chlorinated paraffins (C18-20)
- Medium-chain chlorinated paraffins (C14-17)
- Methylene chloride
- Trichloroethylene (TCE)
Yesterday's action follows EPA's August 2011 Discussion Guide that outlined the agency's preliminary prioritization plan. EPA states that existing chemical management "can best be met via legislative reform of TSCA to improve EPA's chemical management authorities," and cast the current effort as strategy in the absence of legislative reform.
EPA's overall approach has three primary components:
- Perform risk assessments and take "risk management" action for chemicals with well-characterized hazard concerns and "the possibility" of significant exposure.
- Screen "thousands of other compounds to determine which ones warrant further attention", and
- Work toward making chemical information available.
The TSCA Work Plan is no more than EPA's effort to prioritize for further review select chemicals from the total universe of chemicals. EPA states that designation as a Work Plan Chemical does not equate to an agency finding of "risk to human health or the environment." The TSCA Work Plan by itself is not a risk assessment. Thus, there should be no implications that the Work Plan Chemicals are chemicals of concern.
We are, however, concerned by the history of lists; when chemicals appear on prioritization lists – whether in the U.S., Canada, Europe, or elsewhere – there are significant reverberations. When chemicals are listed, companies that produce or use these chemicals often see heightened media attention and public scrutiny coupled with market and regulatory impacts.
A preliminary review of the Work Plan's two-step procedure that was used to identify the 83 substances for initial review suggests that EPA may have missed key considerations in its approach to scoring. In step 1, chemicals with possible human health or environmental toxicity are selected if they meet certain criteria. In step 2, these candidate chemicals are numerically ranked for hazard, exposure, and potential persistence and/or bioaccumulation.
Step 1 selection turns on whether chemicals: (a) have persistent, bioaccumulative, and toxic ("PBT") properties, (b) are probable or known carcinogens, (c) exhibit neurotoxicity, (d) were detected through human or environmental biomonitoring programs, or (e) are used in children's products or consumer products. Based on a review of the two documents that EPA released, some of these criteria are vaguely worded and unclear.
For example, chemicals such as phthalic anhydride – which EPA's Work Plan states is "widely used in consumer products" – is commonly added to resins. These resins are then used in the manufacture of consumer products, such as paints and coatings. The Work Plan fails to clarify whether EPA considers remnant manufacturing process residues in consumer products the same as primary constituents of consumer products. Further, scoring appears not to account for basic principles of chemistry that impact exposure. Phthalic anhydride, for instance, cannot remain phthalic anhydride in environments with water molecules. Although this chemical property is an important and ubiquitous limitation on exposure, there is no indication that it was considered in scoring. Similarly, EPA appears to have ignored whether the substances selected for priority treatment are already subject to extensive regulation.
Companies that produce or use Work Plan Chemicals should begin work now to ensure that upcoming agency risk assessments on priority chemicals are accurate and science-based. The agency noted data limitations in its prioritization process. This leaves the door open for companies to ensure that EPA has the most recent, relevant science and that exposure characterizations are well-developed, together with the other elements of a compelling risk assessment.
The agency's risk assessments will have broad implications. Companies involved in Work Plan Chemicals should develop targeted strategies both within their organizations and in concert with other industry participants to advocate for a rational, science-based approach to protecting human health and the environment.
For more information, please contact Keller and Heckman's Chemical Control team at firstname.lastname@example.org.