Earlier today, US EPA released the inaugural draft list of 20 “high priority” and 20 “low priority” chemicals for risk evaluation purposes as required by the 2016 amendments to the Toxic Substances Control Act (TSCA). EPA must finalize the listings by December 2019, at which point “high priority” chemicals will be required to go through the new TSCA risk evaluation process (the “low priority” designation indicates that risk evaluation is not warranted at this time).

There will be a 90-day comment period, upon publication of the draft list notification in the Federal Register (scheduled for March 21), with the aim of collecting additional information from the public regarding “uses, hazards, and exposure for these chemicals.”

When prioritization is completed later this year, a 3-year risk evaluation process will be initiated to determine if the “high priority” chemicals, under their conditions of use, present an unreasonable risk to human health and the environment. In announcing the list, EPA made clear that the “high or low” designation does not mean that the agency “has determined the chemical poses unreasonable risk or no risk to human health or the environment; it means we are beginning the prioritization process.”

Most notably, the draft “high priority” chemical list includes formaldehyde, which the agency recently dropped (to much criticism from environmental groups and Democratic Members of Congress) as a priority chemical under the Integrated Risk Information System (IRIS), despite years of work under that program. By shifting the formaldehyde assessment to the TSCA program, EPA emphasized that the agency will build off the existing IRIS work but also be able to streamline potential regulatory action to address any identified risks from the use of formaldehyde.

“Moving forward evaluating formaldehyde under the TSCA program does not mean that the formaldehyde work done under IRIS will be lost. In fact, the work done for IRIS will inform the TSCA process. By using our TSCA authority EPA will be able to take regulatory steps; IRIS does not have this authority.” – Alexandra Dapolito Dunn, Assistant Administrator for EPA’s Office of Chemical Safety and Pollution Prevention.

The EPA action is unlikely to quell calls for prompt release of the IRIS risk assessment for formaldehyde, which has been near-completion for almost two years (after an initial draft assessment in 2010 was the subject of intense opposition based on the agency’s preliminary finding that exposure to the substance was associated with increased risk for leukemia). Significantly, the TSCA review process is likely to be narrower and focused on a limited set of uses of the chemical, whereas an IRIS risk assessment would have broader applicability for regulators and toxicologists seeking to assess a wide range of uses.

In addition to formaldehyde, the 20 high priority candidate chemicals include seven chlorinated solvents, six phthalates, four flame retardants, a fragrance additive, and a polymer precursor. The 20 low priority candidate chemicals were selected from EPA’s Safer Chemicals Ingredients List, which includes chemicals that have been evaluated and determined to meet EPA’s “safer choice” criteria.

The EPA home page for prioritization, including the draft list of “high” and “low” priority chemicals, can be found here.