May 21, 2020

New WEEL Documentation for Two Chemicals Available for Public Comment

The Occupational Alliance for Risk Science (OARS) Workplace Environmental Exposure Level (WEEL) Committee has reviewed the WEEL values for methoxytridecafluoroheptene isomers (MPHE) and 1,1,1,2,3,4,4,5,5,5-Decafluoropentane (HFC-4310mee). EPA’s website describes MPHE as a mixture of structural and stereo isomers with a manufacturer-recommended acceptable exposure limit (AEL) of 500 ppm as an eight-hour time-weighted average. The agency lists MPHE as an acceptable substitute in cleaning solvents for precision cleaning. According to the National Institutes of Health PubChem database, HFC-4310mee is used in industry as a solvent.

The WEEL documentation for both chemicals is now available for comment. Individuals must request copies of the public comment drafts by emailing Dr. Patricia McGinnis. The comment deadline for both MPHE and HFC-4310mee is June 22, 2020. More information can be found in the news section of the OARS website.

WEELs are airborne concentration limits that provide guidance for protecting most workers from adverse health effects related to occupational chemical exposures. The table of WEEL values is available on the OARS website.