Titanium nitride

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study

Qualifier:

according to guideline

Guideline:

OECD Series on Testing and Assessment No. 29 (23-Jul-2001): Guidance document on transformation/dissolution of metals and metal compounds in aqueous media

Deviations:

no

GLP compliance:

not specified

Type of method:

other: transformation/dissolution

Water solubility:

8.77 µg/L

Temp.:

21.5 °C

pH:

6

Remarks on result:

other: T/D pre-test (loading 100 mg/L) at pH 6: After 24 h the mean concentrations were: 8.77 ± 4.23 μg Ti/L and 8.76 ± 4.46 μg NH3/L

Water solubility:

< 0.083 µg/L

Temp.:

21.5 °C

pH:

8

Remarks on result:

other: T/D pre-test (loading 100 mg/L) at pH 8: After 24 h the mean concentrations were < LOD (LOD = 0.083 μg Ti/L) and 11.6 ± 4.7 μg NH3/L

Water solubility:

ca. 7.76 µg/L

Temp.:

21.5 °C

pH:

ca. 6

Remarks on result:

other: T/D main test (loading 10 mg/L) at pH 6: After 7 days the mean concentrations were: 7.76 ± 2.82 μg Ti/L and 9.74 ± 0.98 μg NH3/L

Water solubility:

< 0.197 µg/L

Temp.:

21.5 °C

pH:

ca. 6

Remarks on result:

other: T/D main test (loading 1 mg/L) at pH 6: After 28 days the mean concentrations were < 0.197 μg Ti/L and 12.1 ± 0.7 μg NH3/L

Water solubility:

ca. 23.8

Temp.:

21.5

pH:

6

Remarks on result:

other: T/D main test (loading 100 mg/L) at pH 6: After 7 days the mean concentrations were: 23.8 ± 6.6 μg Ti/L and 20.6 ± 4.9 μg NH3/L

Details on results:

The screening test showed, that the titanium release is higher at pH 6 than at pH 8 after 24 hours.
Due to the higher solubility at pH 6 the full T/D test was performed at this pH. After 7 or 28 days, as appropriate, titanium and ammonium concentrations were measured.

Conclusions:

In conclusion, the results showed that the highest measured solubility (with 100 mg/L loading and pH 6) after 7 days was 23.8 ± 6.6 μg Ti/L.

Executive summary:

A transformation/dissolution (T/D) test, in accordance with OECD Series on Testing and Assessment No. 29, was carried out to study the potential of titanium nitride (100% purity) to release metal ions into the environment. A 24-hour screening test was conducted to determine the pH of maximum titanium release at pH 6 and 8 with a loading rate of 100 mg/L. Based on the results, a full main test was performed at pH 6. Under the described conditions the mean titanium concentration after 28 days with a loading rate of 1 mg/L was < 0.197 µg/L, after 7 days with a loading rate of 10 mg/L the mean titanium concentration was 7.76 µg/L and after 7 days with a loading rate of 100 mg/L the mean concentration of titanium was 23.8 µg/L.

Description of key information

Titanium nitride was tested in accordance with OECD Guidance Document No. 29 (transformation/dissolution test). The highest solubility was measured with a loading rate of 100 mg/L at pH 6 after 7 days, which was 23.8 µg Ti/L.

Key value for chemical safety assessment

Water solubility:

23.8 µg/L

at the temperature of:

21.5 °C

Additional information

A transformation/dissolution test in accordance with OECD guidance document No. 29 was carried out to study the potential of titanium nitride (100% purity) to release metal ions into the environment. A 24-hour screening test was conducted to determine the pH of maximum titanium release. Based on the results, a full main test was performed at pH 6. The mean titanium concentration after 28 days with a loading rate of 1 mg/L was < 0.197 µg/L, after 7 days with a loading rate of 10 mg/L the mean titanium concentration was 7.76 µg/L and after 7 days with a loading rate of 100 mg/L the mean concentration of titanium was 23.8 µg/L.