A proposed approach put forward by the US defence department for developing an occupational exposure level for trichlorethylene (TCE) is set to come under scrutiny.
The National Academies of Sciences (NAS) has appointed a provisional committee to examine the proposal, which also includes developing a TCE cancer slope factor, to estimate the risk of cancer for situations in which vapour intrusion is the exposure pathway.
A NAS statement says 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 associated with calculating an OEL.
The eight member committee is provisional, pending a 20-day consultation that ends on 14 February.
TCE is included in the first ten existing chemicals that are undergoing risk evaluation under the TSCA.
It is also the subject of two 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.
The rules had been proposed in the final days of the Obama administration, with the intention of banning the substance’s use in vapour degreasing, as an aerosol degreaser and as a spot cleaner. However the EPA has signalled it is shelving the TCE proposals.