Nickel bis(dihydrogen phosphate)

Endpoint summary

Description of key information

Value used for CSA (read-across from Nickel sulphate):

NOAEL (oral, systemic, animal): 10 mg Ni sulphate hexahydrate /kg bw/day (or 2.2 mg Ni/kg bw/day) (Heim et al. 2007)

NOAEC (inhalation, local, animal): 0.12 mg Ni sulphate hexahydrate /m³ air ( or 0.027 mg Ni/m³air) (Dunnick et al., 1995)

Additional information

Data for repeated-dose toxicity of nickelbis(dihydrogen phosphate)via oral exposure are read-across from Ni sulphate. In addition, a summary document on the read-across assessment and systemic oral toxicity of nickel compounds can be found as a background document inAppendix B1of the CSR (and Section 7.5.1 of IUCLID). In a 2- year OECD 451 carcinogenicity study, decreased body weight gain ranging from 4% to 12% was recorded (male and female rats combined) following oral gavage of 2.2 to 11 mg Ni/kg bw/day. A dose-related reduced survival achieving statistical significance at the two highest dose levels was seen in females (Heim et al., 2007). The LOAEL of 6.7 mg Ni/kg bw/day based on reduced body weight and increased mortality together with a NOAEL of 2.2 mg Ni/kg bw/day are taken forward to the risk characterisation for oral repeated dose toxicity. These data are considered relevant for the risk assessment of nickel bis(dihydrogen phosphate) and are taken forward to the Risk Characterisation.

Data for repeated-dose toxicity via inhalation exposure are read-across from Ni sulphate. Chronic lung inflammation including lung fibrosis in rats results from long-term exposure via inhalation to a concentration of 0.056 mg Ni/m³or 0.25 mg nickel sulphate hexahydrate/m³(NTP, 1996a; Dunnick et al., 1995). Nickel sulphate fulfils the criteria for classification as STOT RE 1; H372 since chronic lung inflammation including lung fibrosis results from long-term exposure via inhalation to a concentration of 0.056 mg Ni/m³. A LOAEC for repeated dose toxicity via inhalation of 0.056 mg Ni/m³for lung inflammation and fibrosis, and a NOAEC of 0.027 mg Ni/m³for these effects based on the chronic study of nickel sulphate by NTP, are used in the risk characterization of nickelbis(dihydrogen phosphate).

The following information is taken into account for any hazard / risk assessment:

ORAL: Data are read-across from Ni sulphate. A 2-year oral carcinogenicity study reported a NOAEL of 10 mg/kg body weight/day (2.2 mg Ni/kg b. w. /day) and a LOAEL of 30 mg/kg body weight/day (6.7 mg Ni/kg b. w. /day). The LOAEL of 6.7 mg Ni/kg bw/day based on reduced body weight and increased mortality together with a NOAEL of 2.2 mg Ni/kg bw/day is taken forward to the risk characterisation. A summary document on this topic is provided as a background document in section 7.5.1 of IUCLID and inAppendixB1of the CSR.

INHALATION: Data are read-across from Ni sulphate. Chronic lung inflammation including lung fibrosis results from long-term exposure via inhalation to a concentration of 0.056 mg Ni/m³or 0.25 mg nickel sulphate hexahydrate/m³(LOAEC). Nickel sulphate fulfils the criteria for classification as STOT RE 1; H372. A concentration of 0.027 mg Ni/m³(MMAD = 2.5 µm) corresponding to the NOAEC for respiratory toxicity effects in rats is taken forward for the risk characterisation.

DERMAL: There was no available information to determine a NOAEL/LOAEL for the dermal route. Testing by the dermal route has been waived as described in IUCLID Section 7.5.3.

Justification for classification or non-classification

Ni bis(dihydrogen phosphate) was classified as STOT RE 1; H372 in the 1st ATP to the CLP Regulation. Background information regarding this classification is provided in the discussion section above.