Iridium

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study, GLP status not known, fully adequate for assessment.

Qualifier:

equivalent or similar 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

Qualifier:

according to guideline

Guideline:

other: UN Transformation/Dissolution Protocol (T/D) for Metals and Sparingly Soluble Metal Compounds.

Deviations:

no

GLP compliance:

not specified

Type of method:

other: Transformation/dissolution

Water solubility:

0.02 µg/L

Conc. based on:

element

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Temp.:

22.1 °C

pH:

>= 5.96 - <= 6.04

Remarks on result:

other: pH 6 24-hr scoping study. Test Duration: 24 Hours, Ir Loading: 100 mg/L, σ: 0.02, Temperature Range: 21.2 - 23.4°C, DO: 4.4 - 7.0 mg/L

Water solubility:

0.02 µg/L

Conc. based on:

element

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Temp.:

21.6 °C

pH:

>= 8.48 - <= 8.71

Remarks on result:

other: pH 8 24-hr scoping study. Test Duration: 24 Hours, Ir Loading: 100 mg/L, σ: 0.02, Temperature Range: 20.6 - 22.2°C, DO: 7.0 - 7.9 mg/L

Water solubility:

0 µg/L

Conc. based on:

element

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Temp.:

21.3 °C

pH:

>= 5.89 - <= 6.43

Remarks on result:

other: Test Duration: 28 Days, Ir Loading: 1 mg/L, σ: 0.00, Temperature Range: 20.6 - 21.6°C, DO: 7.3 - 8.8 mg/L

Water solubility:

0 µg/L

Conc. based on:

element

Loading of aqueous phase:

10 mg/L

Incubation duration:

7 d

Temp.:

21.5 °C

pH:

>= 5.81 - <= 6.02

Remarks on result:

other: Test Duration: 7 Days, Ir Loading: 10 mg/L, σ: 0.00, Temperature Range: 20.9 - 21.7°C, DO: 7.3 - 10.0 mg/L

Water solubility:

0 µg/L

Conc. based on:

element

Loading of aqueous phase:

100 mg/L

Incubation duration:

7 d

Temp.:

21.5 °C

pH:

>= 5.81 - <= 6

Remarks on result:

other: Test Duration: 7 Days, Ir Loading: 100 mg/L, σ: 0.00, Temperature Range: 20.9 - 21.7°C, DO: 7.3 - 9.9 mg/L

Details on results:

The results for the 24 hour scoping tests at pH 6 and 8.5 reveal that Ir was within the sub-µg/L analytical detection limits, and singularly unreactive at either pH. The 28-day and 7-day definitive T/D tests for the 1, 10 and 100 mg Ir/L loadings, comducted at pH 6, reveal that within analytical detection limits, Ir metal was unreactive, yielding net values of 0.00 µg/L at all sampling times.

None of the concentrations exceeded the acute ERVs (ecotoxicity reference values).

Definitive 7 and 28 days T/D tests were only performed at pH 6 on the grounds that metals are generally more reactive at this pH than pH 8.5

Conclusions:

Interpretation of results (migrated information): insoluble (< 0.01 mg/L)
The 28-day and 7 -day definitive T/D tests for the 1, 10 and 100 mg Ir/L loadings reveal that within analytical detection limits (LOQ: 0.01 - 0.1 μg/L) Ir metal was unreactive, yielding net values of 0.00 µg/L at all sampling times.

Executive summary:

CANMET (2011) is a guideline experimental study, following the OECD T/D testing protocol. The study is considered to be reliable and is used as a key study for this endpoint. 24-hour scoping studies were conducted at pH 6 and pH 8.5, with 7-day and 28-day definitive tests then conducted at pH 6. The The 28-day and 7-day definitive T/D tests for the 1, 10 and 100 mg Ir/L loadings reveal that within analytical detection limits (LOQ: 0.01 - 0.1 μg/L) Ir metal was unreactive, yielding net values of 0.00 µg/L at all sampling times.

Description of key information

The 28-day and 7 -day definitive T/D tests for the 1, 10 and 100 mg Ir/L loadings reveal that within analytical detection limits (LOQ: 0.01 - 0.1 μg/L) Ir metal was unreactive, yielding net values of 0.00 µg/L at all sampling times.

Key value for chemical safety assessment

Water solubility:

0 µg/L

at the temperature of:

22 °C

Additional information

CANMET (2011) is a guideline experimental study, following the OECD T/D testing protocol. The study is considered to be reliable and is used as a key study for this endpoint.24 -hour scoping studies were conducted at pH 6 and pH 8.5, with 7 -day and 28 -day definitive tests then conducted at pH 6. The The 28-day and 7 -day definitive T/D tests for the 1, 10 and 100 mg Ir/L loadings reveal that within analytical detection limits (LOQ: 0.01 - 0.1μg/L) Ir metal was unreactive, yielding net values of 0.00 µg/L at all sampling times.