EPA Proposes to Regulate Certain PBT Chemicals

Posted on: August 5, 2019

by John J. Kowalski, CHMM

Photo of the US EPA Building - Learn about the EPA Proposing to Regulate Certain PBT Chemicals

On July 29, 2019, the U.S. Environmental Protection Agency (EPA or the Agency) published a proposed rule, under Section 6(h) of the Toxic Substances Control Act (TSCA), to address five persistent, bioaccumulative, and toxic (PBT) chemicals.  Under the proposed rule, EPA would impose certain prohibitions and recordkeeping requirements upon the four PBT substances identified in the table below.


Abbreviation Chemical Name CAS RN
2,4,6-TTBP 2,4,6-Tris(tert-butyl)phenol 732-26-3
DecaBDE Decabromodiphenyl ether 1163-19-5
PCTP Pentachlorothiophenol 133-49-3
PIP (3:1) Phenol, isopropylated, phosphate (3:1) 68937-41-7

The Agency would also impose certain downstream notification requirements upon PIP (3:1).  In addition, EPA evaluated the uses of Hexachlorobutadiene (HCBD), but is proposing no regulatory action for this substance.

You may be affected by this proposed rule if you manufacture, import, process, distribute in commerce, or commercially use 2,4,6-TTBP, DecaBDE, PCTP, PIP (3:1), or products containing these chemicals. Finally, this proposed rule triggered the export notification requirements under TSCA Section 12(b) for 2,4,6-TTBP, DecaBDE, PCTP, PIP (3:1), and products containing these chemicals. Comments on the proposed rule must be received on or before September 27, 2019.


Recommended Action Items

  • Review the proposed rule; and
  • Consider submitting comments on or before September 27, 2019.



Environmental Protection Agency.  “Regulation of Persistent, Bioaccumulative, and Toxic Chemicals Under TSCA Section 6(h).”  Federal Register 84 (29 July 2019): 36728-36760.

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