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November 2, 2022

Lynn L. Bergeson Quoted by Chemical Watch in Article “TSCA workplace exposure limits not in works for three substances”

Bergeson & Campbell, P.C.

On November 2, 2022, Chemical Watch quoted Lynn L. Bergeson, Managing Partner, Bergeson & Campbell, P.C. (B&C®), regarding the U.S. Environmental Protection Agency’s (EPA) confirmation that it does not plan to develop Toxic Substances Control Act (TSCA) ‘existing chemical exposure limits’ (ECEL) for three of the first ten chemicals evaluated under the amended law: the colourant PV29, the flame retardant HBCD and the solvent NMP. 

It could mean the agency “is planning to pursue either more or less stringent requirements than an Ecel under TSCA”, said Lynn Bergeson, managing partner of the law firm Bergeson & Campbell. 

For example, the EPA “may be considering a ban as the most appropriate path forward” for HBCD, she said. The agency has noted that the flame retardant’s use has declined “dramatically” in recent years, she said.  


Ms Bergeson said she suspects the agency “decided not to develop an Ecel because of the inherent scientific issues in the PV29 risk evaluation”. 

The EPA should have used dosimetry modelling that quantified retained dose from animal studies, rather than relying on deposited dose as the metric for determining unreasonable risk, she said.  

Dosimetry involves estimating the internal dose of a substance in individuals to better link external exposures with potential biological responses. 

The Office of Research and Development (ORD) is close to issuing a final peer-reviewed version of the multi-path particle dosimetry (MPPD) model, she said, which can be used to calculate retained dose and “will represent the best available science”.  

The EPA “may move forward with issuing its draft risk management rule on PV29 to maintain optics”, Ms Bergeson said. But it “may well revise the PV29 risk evaluation and re-quantify risks using the peer-reviewed MPPD model and retained dose”. 

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