Rhenium

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:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study followed a standard guideline and is considered to be suitable for use as the key study for this endpoint.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD Environmental Health and Safety Publications Series on Testing and Assessment No. 29. Guidance Document on Transformation/Dissolution of Metals and Metal Compounds in Aqueous

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Rhenium

EC Number:

231-124-5

EC Name:

Rhenium

Cas Number:

7440-15-5

Molecular formula:

Re

IUPAC Name:

rhenium

Details on test material:

- Name of test material (as cited in study report): rhenium powder (anhydrous)

- Physical state: powder, granules < 1 mm

- Lot/batch No.: Re-18/08/2010

- Expiration date of the lot/batch: 18 September 2012

- Stability under test conditions: Not tested. Assumed to be stable.

- Storage condition of test material: Room temperature; in the dark (poly ethylene gastight bag in argon atmosphere

Results and discussion

Any other information on results incl. tables

In the test vessels with a loading of 100 mg/L rhenium powder, average dissolved rhenium concentrations of 338 μg Re/L with a variation coefficient of 2% and of 390 μg Re/L with a variation coefficient of 4% were measured in the test medium at pH 6 and pH 8 respectively after a exposure of 24 h.

Applicant's summary and conclusion

Conclusions:

In the test vessels with a loading of 100 mg/L rhenium powder, average dissolved rhenium concentrations of 338 μg Re/L with a variation coefficient of 2% and of 390 μg Re/L with a variation coefficient of 4% were measured in the test medium at pH 6 and pH 8 respectively after a exposure of 24h.

Executive summary:

The experiments of the study (dissolution characteristics of rhenium powder) have been performed according to the instructions of the OECD Test Guideline No 29 (2001), the study plan and the SOPs to be applied. The determination of the concentration of dissolved rhenium has been delegated to the ISO 9001:2008 accredited Test Site CANMET-MMSL, Canada.

The pH measured in the test media and in the blank and test item vessels at pH 6 and pH 8 varied from 5.99 to 6.02 and from 7.96 to 8.00. All measured data were within the specifications of ± 0.2.

The measured dissolved oxygen concentrations in the test medium and in the blank controls and test vessels at pH 6 and 8 varied between 8.39 and 8.55 and were higher than the value of ± 6 mg O2/L which is considered as 70% of the saturation concentration in contact with the air.

The concentration rhenium (Re) in the test media and in the blank control vessels at pH 6 and pH 8, were always below the limit of detection (0.1 μg Re/L).

In the test vessels with a loading of 100 mg/L rhenium powder, average dissolved rhenium concentrations of 338 μg Re/L with a variation coefficient of 2% and of 390 μg Re/L with a variation coefficient of 4% were measured in the test medium at pH 6 and pH 8 respectively after a exposure of 24h.

Based on the results of the experiments we may conclude that rhenium showed dissolution above detection limit and therefore, may be important in the design of a full test with the objective for classification purposes according to the EU-CLP and UN-Globally Harmonized System. However, as the level of dissolution in the screening study is well below the ERV a full T/D test is not required for this substance.