Persistent, Bioaccumulative, and Toxic (PBT) Chemicals under TSCA Section 6(h)
As required under the Toxic Substances Control Act (TSCA), as amended by the Frank R. Lautenberg Chemical Safety for the 21st Century Act, EPA is proposing for public comment a rule to reduce exposures to certain chemicals that are persistent, bioaccumulative and toxic (PBT). These chemicals build up in the environment over time and can therefore have potential risks for exposed populations including the general population, consumers and commercial uses, susceptible subpopulations (such as workers, subsistence fishers, tribes and children).
EPA is asking for public comment on the proposal for 60 days following publication in the Federal Register at docket EPA-HQ-OPPT-2019-0080 on www.regulations.gov. A final rule must be promulgated no later than 18 months after the proposed rule.
On this page:
- Uses and proposed risk management for five PBT chemicals under TSCA section 6(h)
- Decabromodiphenyl ether (DecaBDE)
- Phenol, isopropylated phosphate (3:1) (PIP (3:1))
- 2,4,6-Tris(tert-butyl)phenol (2,4,6-TTBP)
- Hexachlorobutadiene (HCBD)
- Pentachlorothiophenol (PCTP)
- Additional information
The Frank R. Lautenberg Chemical Safety for the 21st Century Act, enacted on June 22, 2016, includes a provision under section 6(h) requiring EPA to take expedited action on specific PBT chemicals by proposing a rule under section 6(a) no later than three years after enactment to address risk and reduce exposures to the extent practicable. EPA identified five PBT chemicals for expedited action in 2016, following criteria outlined in section 6(h) of TSCA. No risk evaluation was required for these chemicals.
EPA continues to meet the requirements of the amendments to TSCA by proposing a rule on certain PBT chemicals by June 2019. The specific provisions outlined in the proposed rule will protect human health and the environment because they address risks and reduce exposure to the PBT chemicals to the extent practicable.
Below is a summary of the uses, identified hazards, and proposed risk management actions for each of the five PBT chemicals.
|Chemical||Uses and Identified Hazards||Proposed Risk Management Actions|
|Decabromodiphenyl ether (DecaBDE)||DecaBDE is used as a flame retardant in textiles,
plastics, wiring insulation, and building
and construction materials. Learn more about DecaBDE uses.
Identified Hazards – DecaBDE is toxic to aquatic
invertebrates, fish, and terrestrial invertebrates.
Data indicate the potential for developmental,
neurological, and immunological effects, general
developmental toxicity, liver effects, and carcinogenicity. While many uses of DecaBDE have ceased, EPA has concluded that humans or the environment are likely exposed to DecaBDE under the conditions of use identified in the proposed rule.
EPA is proposing to prohibit the manufacture (including import), processing, and distribution in commerce of DecaBDE, and products containing DecaBDE, for all uses, except for the following:
Phenol, isopropylated phosphate (3:1)
|PIP (3:1) is used as a flame retardant in consumer products and as a lubricant, hydraulic fluid, and in other industrial uses. Learn more about PIP (3:1) uses.
Identified Hazards – PIP (3:1) is toxic to aquatic plants, aquatic invertebrates, sediment invertebrates and fish. Data indicate the potential for reproductive and developmental effects, neurological effects and effects on systemic organs, specifically adrenals, liver, ovary, heart, and lungs.
EPA is proposing to:
|2,4,6-TTBP is used as an intermediate/reactant in processing, and is incorporated into formulations destined for fuel and fuel-related additives, as well as into formulations intended for the maintenance or repair of motor vehicles and machinery, including in oils and lubricants. Learn more about 2,4,6-TTBP uses.
Identified Hazards – 2,4,6-TTBP is toxic to aquatic plants, aquatic invertebrates, and fish. Surveyed animal data indicate the potential for liver and developmental effects. The studies presented in this document demonstrate these hazardous endpoints. EPA has concluded that exposure to 2,4,6-TTBP under the conditions of use is likely.
EPA is proposing to:
|Hexachlorobutadiene (HCBD)||HCBD is used as a halogenated aliphatic hydrocarbon that
is produced as a byproduct during the manufacture of
chlorinated hydrocarbons, particularly perchloroethylene, trichloroethylene, and carbon tetrachloride and is subsequently burned as a waste fuel. Learn more about HCBD uses.
Identified Hazards – HCBD is toxic to aquatic invertebrates, fish, and birds, and has been identified as a possible human carcinogen. Data indicate the potential for renal, reproductive, and developmental effects.
|EPA has evaluated the conditions of use of hexachlorobutadiene and is proposing no action since the exposures are already regulated under other environmental laws.|
|PCTP, which is also called PCTP, is used to make rubber more pliable in industrial uses. Learn more about PCTP uses.
Identified Hazards – PCTP is toxic to protozoa, fish, terrestrial plants, and birds. Data for analogous chemicals (pentachloronitrobenzene and hexachlorobenzene) indicate the potential for liver and reproductive effects. However, no animal or human hazard data has been identified.
|EPA is proposing to prohibit the manufacture (including import), processing, and distribution in commerce of PCTP, and products containing PCTP, for use in manufacturing in concentrations that exceed 1% by weight.|
EPA conducted letter peer reviews of exposure and hazard information for the five PBT chemicals. EPA also accepted written comments on the charge questions and other documents to be considered by the peer reviewers. These materials are available in docket EPA-HQ-OPPT-2018-0314.
On Thursday, September 7, 2017, at 2 pm EDT, EPA hosted a webinar, “Use Information for Persistent, Bioaccumulative, and Toxic (PBT) Chemicals Under TSCA Section 6(h).” This webinar provided background on the requirements for PBT chemicals under amended TSCA and explained to interested parties the process for gathering use and exposure information the five PBT chemicals.
public dockets for each of the five PBT chemicals to facilitate receipt of information on exposure and use which may be useful to the Agency’s rulemaking effort. To read the comments EPA received, visit the docket for each chemical.