On March 27, 2013, as part of the Toxic Substances Control Act (TSCA) Work Plan, the U.S. Environmental Protection Agency (EPA) announced that it will begin assessments on 23 chemicals, with a specific focus on flame retardant chemicals. According to EPA’s press release, EPA will evaluate 20 flame retardant chemicals, conducting full risk assessments for four of the flame retardants, three of which are on the TSCA Work Plan, and one of which was the subject of an Action Plan. In addition to the flame retardant chemicals, EPA will begin developing risk assessments on three other TSCA Work Plan chemicals: octamethylcyclotetrasiloxane (D4); 1-bromopropane; and 1,4 dioxane. The press release is available online. More information regarding the TSCA Work Plan chemicals is available online.
The four flame retardants for which EPA will conduct full risk assessments are:
- 2-Ethylhexyl ester 2,3,4,5- tetrabromobenzoate (TBB);
- 1,2- Ethylhexyl 3,4,5,6-tetrabromo-benzenedicarboxylate or (2-ethylhexyl)-3,4,5,6 tetrabromophthalate (TBPH);
- Tris(2-chloroethyl) phosphate (TCEP); and
- Hexabromocyclododecane (HBCD).
Each of these chemicals has been placed into a “structure-based group” which includes other structurally related flame retardants which, according to EPA, currently lack sufficient data needed for a full risk assessment. The structure-based groups are identified as and comprised of the following chemicals:
- Brominated Phthalates Group: Includes TBB and TBH (from above) and five other members:
- 2-(2-Hydroxyethoxy) ethyl 2-hydroxy propyl 3,4,5,6 tetrabromobenzenedicarboxylate;
- 3,4,5,6-Tetrabromo-1,2-benzenedicarboxylic acid, mixed esters with diethylene glycol and propylene glycol;
- 1,2- (2,3-dibromopropyl) benzenedicarboxylate; and
- Two chemicals whose identities have been claimed confidential, “Confidential A” and “Confidential B.”
- 2-(2-Hydroxyethoxy) ethyl 2-hydroxy propyl 3,4,5,6 tetrabromobenzenedicarboxylate;
- Chlorinated Members of the Halogenated Phosphate Esters Group, which includes TCEP, 2-Propanol, 1,3-dichloro-, phosphate (TDCPP), and 2-Propanol, 1-chloro-, phosphate (TCPP).
- Cyclic Aliphatic Bromides Group, which includes HBCD and 1,2,5,6-Tetrabromocyclooctane.
EPA plans to use the understanding developed on the four chemicals receiving full risk assessments to determine what can be determined about the biological and environmental behavior of the other chemicals in the corresponding structure-based group.
EPA also identified a fourth flame retardant group, tetrabromo bisphenol A and related chemicals, within which one chemical, Tetrabromobisphenol A (TBBPA), has sufficient data to conduct a risk assessment. EPA states that, when it updates its TSCA Work Plan, TBBPA will become a candidate for future risk assessment.
Separate from the Work Plan and Action Plan efforts, EPA states that it is assessing the environmental fate of eight other flame retardants. EPA noted that its Work Plan prioritization methodology ranked these chemicals as “high” for persistence, bioaccumulation, and/or exposure potential, but also indicated there are not adequate data to conduct risk assessments. EPA plans to study the mechanisms by which these chemicals may break down into degradants, and how the persistence and bioaccumulation potentials of the degradants compare to those of the parent compounds. The eight chemicals include:
- 1,2,4,5-tetrabromo-3,6-bis(pentabromophenoxy)-benzene or Tetradecabromo-1,4-diphenoxybenzene;
- 1,2 bis(Penetabromophenyl) ethane (DBDPE);
- 1,1′-[1,2-Ethanediylbis(oxy)]bis[2,3,4,5,6-pentabromo-benzene] or 1,2-Bis(2,3,4,5,6-pentabromophenoxy) ethane;
- 1,1′-[1,2-Ethanediylbis(oxy)]bis[2,4,6-tribromobenzene] or 1,2-bis (2,4,6-Tribromophenoxy) ethane (TBE);
- 2,4,6-Tris-(2,4,6-tribromophenoxy)-1,3,5-triazine;
- Benzene,1,3,5-tribromo-2-(2,3-dibromopropoxy) (DPTE); and
- Two chemicals whose identities are confidential, “Confidential C” and “Confidential D.”
In the March 27, 2013, press release, EPA notes that, during its review of data on flame retardant chemicals in commerce, EPA identified approximately 50 flame retardant chemicals that it claims are unlikely to pose a risk to human health, “making them possible substitutes for more toxic flame retardant chemicals.”
In preparing the draft risk assessments, EPA will use information available from “a wide range of publicly available data sources.” EPA encourages companies to submit additional data on these chemicals, “such as unpublished studies and information on uses and potential exposures.” EPA asks for any additional information to be submitted by May 30, 2013. Submissions can be made to docket EPA-HQ-OPPT-2011-0516, available online. EPA asks that the chemical name and CAS number appear in the title of any submission to the docket.
Commentary
The latest round of Work Plan chemicals continues and expands upon the Office of Pollution Prevention and Toxics’ (OPPT) existing large body of work on halogenated flame retardants by teeing up 20 flame retardants while also adding three additional chemicals to the assessment queue. While there may be some economies from EPA’s grouping approach for the flame retardants, the full set of new additions will nonetheless require a significant effort by EPA to work through and complete. For example, each of the three non-flame retardant chemicals brings complexities in that each has received significant attention in the past from OPPT (including, e.g., D-4, which is also currently the subject of an ongoing TSCA Section 4 Enforceable Consent Agreement negotiation) or other parts of EPA (e.g., 1-bromopropane was introduced as an alternative to ozone depleting chemicals).
This new work will be done at the same time that EPA will be working to deliver on its previous existing chemical commitments, including:
- Completion of peer review and finalization of the risk assessments on the 25 Work Plan chemicals for which this commitment was previously made; see online for more information);
- Meeting risk management commitments on ten chemicals and categories which were the subject of Action Plans; and
- Other risk management actions that have been teed up on formaldehyde, glymes, lead, mercury, etc. (see online for more information on the latter two bullet points).
EPA is certainly to be commended for the scale and complexity of its continuing efforts to make progress in dealing with existing chemical issues using its current TSCA authority. At the same time, “the proof is in the pudding” and 2013 should prove illuminating on the question of OPPT’s ability to deliver on its risk assessment and risk management commitments and to do so despite a number of challenges that remain to be overcome (some of which were discussed in Bergeson & Campbell’s 2013 Predictions for EPA’s Office of Chemical Safety and Pollution Prevention available online, and which include, more recently, the impacts of the sequester.