Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:11:p7
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 11 (pt 7/9)
Character Range: 2283091–2286243

excess lifetime cancer risk of 1 in 100,000.
TERA (1999)                         RfC = 0.2 µg/m3              RfC derived on the basis of a benchmark approach using a BMCL10 (HEC) of 0.0017 mg/m3 associated with lung fibrosis from soluble nickel salts in a rat study and an uncertainty factor of 10. This is the same study as considered by the ADTSR (2005).
RIVM (2001)                         TC = 0.05 µg/m3              Tolerable concentration (TC) derived on the basis of a threshold approach from a NOAEC (HEC) of 0.005 mg/m3 associated with respiratory effects in rats, and an uncertainty factor of 100.
Health Canada (1994)                TC = 0.0035 µg/m3            Tolerable concentration (TC) derived on the basis of a threshold approach from a LOAEC (HEC) of 0.0035 mg/m3 associated with respiratory effects from nickel sulfate in rats, and an uncertainty factor of 1000.
                                    TC05 = 0.07 mg/m3            Health Canada also derived a tumorigenic concentration of 5%, TC05, based on epidemiology studies of exposed workers at two nickel refineries (based on nickel sulphate and nickel chloride), and derived from the non-threshold doseresponse curves.
EPAQS (2008)                        TC = 0.02 µg/m3              TC derived assuming a threshold approach is appropriate, based on a LOAEL of 0.02 mg/m3 associated with respiratory tract tumours in occupational nickel exposures, and an uncertainty factor of 1000. TC derived is similar to but slightly lower than that derived on the basis of inflammatory response in experimental animals.
EA (2009b)                          TC = 0.02 µg/m3              Adopted evaluation of EPAQS (2008), noting the value derived is protective of carcinogenic and non-carcinogenic effects.
OEHHA (2009)                        REL = 0.05 µg/m3             Chronic inhalation reference exposure level (REL) for nickel and nickel compounds (except nickel oxide where a higher REL is derived) based on a NOAEL (HEC) of 0.0016 mg/m3 associated with respiratory/lung effects in a 104-week rat study, and an uncertainty factor of 30.
                                                                 OEHHA also provide a non-threshold unit risk for nickel and compounds.
ATSDR (2005)                        Inhalation MRL = 0.09 µg/m3  Chronic inhalation MRL derived on the basis of a NOAEL (HEC) of 0.0027 mg/m3 associated with lung effects in rats, and an uncertainty factor of 30.
US EPA (IRIS 2012)                  GV = 0.04 µg/m3              Review by the US EPA (last reviewed in 1991) established a range of air guideline values for nickel based on a non-threshold approach with a unit risk derived from occupation studies associated with nickel refinery dust. The guideline value noted here is based on an excess lifetime cancer risk of 1 in 100,000.

11.4.2.3     Identified TRVs
With respect to oral exposures, the more recent review by WHO (2011) is considered appropriate (and most current) and adequately protective of the most critical health effects. The threshold value recommended is considered adequately protective of hypersensitivity responses that may be