Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:3:p5
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 3 (pt 5/8)
Character Range: 2790905–2793761

10-fold factor to address possible carcinogenicity.
International
WHO (2011)            TDI = 0.014 mg/kg/day       WHO DWG TDI based on the same study and uncertainty factor as noted in the ADWG (NHMRC 2011).
WHO (2006 and 2010)   TC = 0.2 mg/m3              TC in air derived on the basis of the most sensitive end point, namely neurotoxicological effects, based on a mean LOAEC (adjusted) of 20 mg/m3 from an occupational inhalation study (mean exposure of 10 years) (Seeber 1989), and an uncertainty factor of 100. The TC derived is lower than that from other key end points such as kidney and liver effects and reproductive/developmental effects. Potential carcinogenic effects have been assessed on the basis of a benchmark dose approach with a BMCL10 of 20 mg/m3 and if a multistage model were considered the TC of 0.2 mg/m3 would be associated with a risk of 1 x10-3.
                      TC = 0.25 mg/m3             The assessment presented by WHO (2006) is an update of the earlier assessment presented in the WHO Air Quality Guidelines (2000) where a TC of 0.25 mg/m3 was derived based on a LOAEL of 102 mg/m3 in dry-cleaning workers, with adjustment for exposure duration (to LOAEL of 24.3 mg/m3) (Mutti et al. 1993), and an uncertainty factor of 100. Further review of PCE by WHO (2010) re-confirmed the guideline of 0.25 mg/m3.
                      TDI = 0.05 mg/kg/day
RIVM (2001)           TDI = 0.016 mg/kg/day       TDI derived on the basis of a NOAEL of 16 mg/kg/day associated with liver effects in a 4-week oral study in rats, and an uncertainty factor of 1000.
                      TC = 0.25 mg/m3             TC adopted based on older WHO (2000) evaluation derived from a LOAEL (adjusted) of 23 mg/m3 from an occupational inhalation study, and an uncertainty factor of 100.
Health Canada (1993)  TDI = 0.014 mg/kg/day       TDI derived on the same basis as noted for the WHO DWG and ADWG.
                      TC = 0.36 mg/m3             TC derived from a LOAEL of 363 (adjusted) mg/m3 associated with multiple effects in mice, and an uncertainty factor of 1000.
ATSDR (1997)          No chronic oral MRL         Nor chronic oral MRL has been established.
                      Inhalation MRL =0.24 mg/m3  The chronic inhalation MRL has been derived on the basis of a LOAEL (adjusted) of 24 mg/m3 associated with neurobehavioural effects in an occupational inhalation study, and an uncertainty factor of 100.
US EPA (2012)         RfD = 0.006 mg/kg/day       RfD derived based on route extrapolation from the inhalation studies.
                      RfC = 0.04 mg/m3            RfC derived on the basis of the midpoint of RfCs derived from 2 studies. An RfC of 0.015 mg/m3 was derived from a LOAEL of 15 mg/m3 associated with colour confusion in an adult occupational study (Cavalleri et al. 1994), and application of a 100-fold