EPA Releases Draft Systematic Review Protocol for TSCA Risk Evaluations

A draft systematic review protocol for chemical substances has been released by the U.S. Environmental Protection Agency (EPA). This protocol details the procedures used by the Agency for the identification, evaluation, and integration of hazard and exposure information for risk evaluations under TSCA. Here we review the protocol and consider its key objectives.

Chemicals of Focus in TSCA Systematic Review

The “Draft Systematic Review Protocol Supporting TSCA Risk Evaluations for Chemical Substances” provides information on several chemicals for which systematic review is being conducted under TSCA, including details of the process relative to each.

Substance NameCAS Registry Number
trans-1,2- Dichloroethylene156-60-5
Ethylene dibromide106-93-4
1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta [g]-2-benzopyran (HHCB)1222-05-5
4,4’-(1-Methylethylidene)bis[2, 6-dibromophenol] (TBBPA)79-94-7
Tris(2-chloroethyl) phosphate (TCEP)115-96-8
Phosphoric acid, triphenyl ester (TPP)115-86-6
Phthalic anhydride85-44-9
Dibutyl phthalate (DBP) (1,2-Benzene- dicarboxylic acid, 1,2- dibutyl ester)84-74-2
Butyl benzyl phthalate (BBP) - 1,2-Benzene- dicarboxylic acid, 1-butyl 2(phenylmethyl) ester85-68-7
Di-ethylhexyl phthalate (DEHP) - (1,2-Benzene- dicarboxylic acid, 1,2- bis(2-ethylhexyl) ester)117-81-7
Di-isobutyl phthalate (DIBP) - (1,2-Benzene- dicarboxylic acid, 1,2-bis-(2methylpropyl) ester)84-69-5
Dicyclohexyl phthalate84-61-7
Diisodecyl phthalate (DIDP)26761-40-0; 68515-49-1
Diisononyl phthalate (DINP)28553-12-0; 68515-48-0
Octamethylcyclotetra- siloxane (Cyclotetrasiloxane, 2,2,4,4,6,6,8,8-octamethyl-) (D4)556-67-2
Asbestos 2 (including Libby Amphibole Asbestos [LAA] and its tremolite, winchite, and richterite constituents)1332-21-4; 12001-29-5; 12001-28-4; 12172-73-5; 17068-78-9; 12172-67-7; 1318-09-8 (12425-92-2, 17068-76-7, 14567-73-8)
1,4-Dioxane supplement123-91-1

Source: U.S. Environmental Protection Agency

Draft Systematic Review Protocol

Development of the protocol follows the EPA's May 2018 release of another document, designed to facilitate the process of chemical risk evaluations under TSCA. The “Application of Systematic Review in TSCA Risk Evaluations” was reviewed subsequently by the National Academies of Sciences, Engineering, and Medicine (NASEM). Utilizing feedback received from NASEM, as well as other sources, the systematic review protocol was established by the Agency.

The new protocol outlines the systematic review approaches applied for evidence identification and evaluation in support of the EPA’s Office of Pollution Prevention and Toxics (OPPT) and its risk evaluations.

Key objectives of the systematic review include:

  • Performing literature searches for the identification of pertinent discipline-specific information
  • Screening studies to determine ones relevant to chemical exposure and hazards
  • Developing evidence tables and literature inventory trees relative to discipline-specific screening criteria
  • Assessing the quality of discipline-specific data
  • Extracting relevant information from studies
  • Integrating hazard and exposure information (includes characterizing data limitations, strengths, and relevance)

The protocol expands on and supersedes the information in the “Application of Systematic Review in TSCA Risk Evaluations”. Public comments on the draft version are currently being accepted. Peer review of the protocol by the TSCA Scientific Advisory Committee on Chemicals (SACC) is scheduled for April of this year.

Accessing More Information

Release of the draft protocol for systematic review represents an important step in the EPA's efforts to improve and better inform chemical risk evaluations under TSCA. More information about the protocol and the systematic review process may be found on the Agency’s website. Additionally, you can visit the ToxPlanet website and blog regularly for information on new developments. Also, be sure to contact us and register for a Free Trial. Our powerful decision support solutions allow you to access vital information on an abundance of chemical substances, quickly and easily. Experience the ToxPlanet difference and see how we can help address your chemical hazard information needs.