DOD Proposal on Trichloroethylene Exposure Levels to be reviewed by the National Academies of Science.
A proposed approach put forward by the US Department of Defense for developing an occupational exposure level for trichloroethylene (TCE) will come under the scrutiny of the National Academies of Sciences (NAS).
The federal scientific body (NAS) has appointed a provisional committee to examine the DOD proposal, which also includes developing a TCE cancer slope factor, to estimate the risk of cancer for situations in which vapor intrusion is the exposure pathway.
NAS said in a statement that important elements of the committee’s review will include:
- the data selection process;
- evidence synthesis;
- dose-response assessments;
- the use of physiologically based pharmacokinetic models; and other factors
- other factors associated with calculating a scientifically sound safety level
The eight-member committee is provisional, pending a 20-day consultation period that ends on February 14, 2019.
TCE is one of the first ten existing chemicals to undergo risk evaluations under the Revised TSCA regulations.
TCE may also be subject to a pair of proposed TSCA section 6 rules. Section 6 gives the EPA power to ban or restrict a chemical if it finds it presents an unreasonable risk to human health or the environment. This unreasonable risk requirement is significant because recent history suggests that TCE vapor may pose an unreasonable risk to human health.
In 2016 TCE vapor intrusion in a mobile home park in El Cajon California, that was located within 100 yards of a shuttered defense plant appears to have caused the deaths of at least two residents of the mobile home park.
The rules proposed under Title 6 of the revised TSCA regulations were proposed in the final days of the Obama administration, with the intention of banning the use of TCE in vapor degreasing applications, and as an aerosol degreaser and spot cleaner. However, it is unclear whether the agency will opt to shelve the TCE proposals.