EPA has announced plans to conduct detailed chemical studies on 83 chemicals and a timeline to complete the studies. More is expected.

On March 1, 2012, the EPA Office of Pollution Prevention and Toxics (OPPT) announced a work plan of 83 chemicals for further review under the Toxic Substances Control Act (TSCA). The agency identified seven chemicals for risk assessment in 2012, and intends to complete some of these assessments this year and initiate new assessments from the work plan in the coming years. EPA stated that, beginning this Spring, it plans to identify specific chemicals for risk assessment in 2013 and 2014. More information on the TSCA Work Plan Chemicals is available online. The announcement also briefly discussed OPPT's efforts to "build the pipeline of future assessment" and its continuing efforts to increase public access to chemical data and information.

  Chemicals Selected for Risk Assessment in 2012

The seven chemicals currently being assessed are:

• Antimony and antimony compounds;
• HHCB (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8,-hexamethylcycl openta[g]-2-benzopyran);
• Long-chain chlorinated paraffins;
• Medium-chain chlorinated paraffins;
• Methylene chloride;
• N-Methylpyrrolidone; and
• Trichloroethylene

In conducting risk assessments on these chemicals, EPA will use information that is available through the data sources cited in the TSCA Work Plan Chemicals Methods Document, as well as other sources. EPA stated that it "would welcome the submission of additional relevant information on these chemicals, such as unpublished studies not already available through the existing literature." To meet the agency's schedule for the completion of risk assessments in 2012, any relevant information should be submitted by March 30, 2012.

  According to EPA, it "anticipates" issuing draft risk assessments for public review and comment as they are completed. If an assessment indicates significant risk, EPA states that it will evaluate and pursue appropriate risk reduction actions as warranted. If an assessment indicates no significant risk, EPA will conclude its current work on that chemical. Over time, the agency will add additional chemicals to the work plan as more data are developed and more chemicals screened.

  How Did EPA Select the TSCA Work Plan Chemicals?

  In September 2011, EPA announced a new approach for identifying priority chemicals for review and assessment under TSCA. The agency conducted an online discussion forum and webinar to gather stakeholder input on proposed criteria and data sources to be used for identifying chemicals for further assessment. More information is available online.

  According to EPA, step 1 of the process it adopted emphasized focusing on chemicals meeting one or more of the following factors:

• Potentiality of concern to children's health;
• Persistent, bioaccumulative and toxic (PBT);
• Probable or known carcinogens;
• Used in children's products;
• Detected in biomonitoring programs, or, a newly added factor; and
• Neurotoxic effects.

EPA also made adjustments to the second stage of its process and developed a hazard, exposure, and persistence/bioaccumulation ranking system to score and screen the chemicals into four priority bins (high, moderate, low or chemicals that could not be scored but may be candidates for information gathering). An outline of the scoring and screening system can be found in the TSCA Work Plan Chemicals document at the link above.

  Using this process, EPA identified 83 chemicals as candidates for risk assessment in the next several years, as they all scored high in this screening process based on their combined hazard, exposure, and persistence and bioaccumulation characteristics. In identifying a smaller set of chemicals for work in any given year, EPA states that it considers a number of factors:

• Whether the chemical was identified as a "High" ranking chemical;
• Whether the chemical reflects more than one of the factors identified in step 1 (for example, chemicals that were identified as a potential concern for children's health and also were persistent, bioaccumulative, and toxic) and whether each of the factors was covered by the set of chemicals;
• Whether certain chemicals, or groups of chemicals, would benefit from some preliminary work to assure that risk assessments are targeted and appropriately scoped, and therefore would best be addressed in an out year;
• Whether certain chemicals, or groups of chemicals, have previously been assessed and addressed by EPA, so that risk assessment in later years may be more appropriate than in the earlier years of the work plan; and
• EPA work load considerations, including scope and timing of work needed on specific chemicals, and existing commitments for assessment.

EPA's messaging about this announcement indicates that this is less of a "new initiative" than a continuation of past efforts to create a template and set of operating procedures for OPPT to better develop the capability to routinely conduct risk assessments. This skill set and operating procedures will be crucial for any hope of success for the program as it attempts to develop risk assessments on potentially tens of chemicals over the near future either as a part of a new legislative mandate or as a continuation of Obama Administration priorities.