Nickel monoxide

Additional information on environmental fate and behaviour

Administrative data

Endpoint:

additional information on environmental fate and behaviour

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

other: OECD 29: Transformation/Dissolution of Metals and Metal Compounds in Aqueous Media

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Nickel oxide

EC Number:

234-323-5

EC Name:

Nickel oxide

Cas Number:

11099-02-8

Molecular formula:

NiO

IUPAC Name:

Nickel(II) oxide

Details on test material:

Black nickel oxide and Green nickel oxide samples tested

Results and discussion

Any other information on results incl. tables

Green NiO (test for cobalt)

Results of the testing on the green nickel oxide found it to be essentially unreactive.

The Ni(aq) (the net concentration change in total dissolved nickel) for the seven- and 28‑day test at 1 mg/L loading at pH 6 exhibiting 0.12 (σ = 0.20, σ_%= 166) µg/L and 0.23 (σ = 0.51, σ_%= 222) µg/L, respectively.  Similar results were obtained at pH 8, with Ni(aq) for the 7- and 28 day test at 1 mg/L loading of -0.03 (σ = 0.03, σ_%= 100) and ‑0.22 (σ = 0.08, σ_% = ‑36) µg/L, respectively. 

For the Seven day tests at the 10 mg/L loading, Ni presented no detectable net average changes in concentration over the seven days for pH 6 or 8. The net change in concentration over the seven days at pH 6 was 0.05 (σ = 0.34, σ_%= 644) µg/L and therefore considered to be unreactive at pH 6. The net change in concentration over the seven days at pH 8 was -0.13 (σ = 0.06, σ_%= 44) µg/L and therefore considered to be unreactive at pH 8.

For the Seven-day tests at the 100 mg/L loadings, the net change in concentration over the seven days at pH 6 was 0.37 (σ = 0.51, σ_%= 137) µg/L and therefore considered to be unreactive at pH 6. The net change in concentration over the seven days at pH 8 was 0.13 (σ = 0.21, σ_%= 165) µg/L; and as with the pH 6 results, NiO green is considered to be unreactive at pH 8.

Black NiO

The test results show that the black nickel oxide was considerably more reactive than the green. Results of the black nickel oxide at pH 6 gave a value of Ni(aq) for the seven day test at the 1 mg/L loading of 82.8 (σ = 11, σ_%= 12) µg/L.  At pH 8, the black nickel oxide is less reactive than at pH 6, with a net change in concentration of Ni over the seven-day period for the 1 mg/L loading of 11.7 (σ = 3.39, σ_%= 29) µg/L. 

Green Nickel Oxide 24 -hr screening for Cobalt release

 

The results for this 24-hr screening test reveal a net average Ni concentration change for the five 100 mg/L loadings of 0.76 (σ = 0.22, σ_%= 28) µg/L. One procedural blank sample and one 0 hr reading were elevated (>1 µg/L) but not removed as outliers. For Co, the results for this 24-hr screening test reveal a net average concentration change for the five 100 mg/L loadings of 0.07 (σ = 0.004, σ_%= 5) µg/L. All procedural blanks and 0 hr readings were < LOQ of 0.01 µg/L.

Applicant's summary and conclusion

Executive summary:

To determine the Globally Harmonized System of Classification and Labelling of Chemicals(GHS) hazard classification of a metal or sparingly soluble metal compound, data derived from applying the transformation/dissolution protocol (T/DP) (United Nations, 2009) are compared to existing ecotoxicity data, ideally determined under similar test conditions. The objectives of this study were to conduct T/D tests on two samples of nickel oxide. In this project, we have evaluated the rate and extent of release of the trace metal Ni from the two nickel oxides in aqueous media at pH 6 and 8 under the conditions of the T/DP.

 

Results of the testing on the green nickel oxide found it to be essentially unreactive, with Ni(aq) (the net concentration change in total dissolved nickel) for the seven- and 28‑day test at 1 mg/L loading at pH 6 exhibiting 0.12 (σ = 0.20, σ_%= 166) µg/L and 0.23 (σ = 0.51, σ_%= 222) µg/L, respectively. These values were less than the acute and chronic ERVs for Ni at pH 6 of 120 µg/L and 2.4 µg/L, respectively. Similar results were obtained at pH 8, with Ni(aq) for the 7- and 28-day test at 1 mg/L loading of -0.03 (σ = 0.03, σ_%= 100) and ‑0.22 (σ = 0.08, σ_% = ‑36) µg/L, respectively. These values were less than the acute and chronic ERVs for Ni at pH 8 of 68 µg/L and 2.4 µg/L, respectively. As the 10 and 100 mg/L loadings for the seven-day tests at pH 6 and 8 exhibited similar sub‑µg/L values of Ni(aq) and since these concentrations were all significantly less than the acute ERVs, the green nickel oxide would not classify under the GHS.

 

The test results show that the black nickel oxide was considerably more reactive than the green. Results of the black nickel oxide at pH 6 gave a value of Ni(aq) for the seven day test at the 1 mg/L loading of 82.8 (σ = 11, σ_%= 12) µg/L. Since the acute ERV for Ni at pH 6 is 120 µg/L, the black nickel oxide would not classify as Acute 1. At pH 8, the black nickel oxide is less reactive than at pH 6, with a net change in concentration of Ni over the seven-day period for the 1 mg/L loading of 11.7 (σ = 3.39, σ_%= 29) µg/L. Since the acute ERV for Ni at pH 8 is 68 µg/L, the black nickel oxide would not classify as Acute 1 at this pH. The 10 mg/L loading was not tested at either pH 6 or 8, but might confirm the classification of this substance as Acute 2/Chronic 2.