Tungsten dioxide

Oxidising properties

Link to relevant study record(s)

Reference

Endpoint:

oxidising solids

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Guideline study.

Qualifier:

according to guideline

Guideline:

EU Method A.17 (Oxidising Properties (Solids))

Deviations:

no

GLP compliance:

no

Contact with:

powdered cellulose

Key result

Sample tested:

test mixture as specified

Parameter:

burning rate

Result:

2.33 mm/s

Result

The mixtures of the test substance with cellulose containing less than 50 % cellulose did not ignite. The tests for mixtures with 50 and 60 % cellulose, respectively, revealed very slow burning rates compared to the reference mixture. Therefore, multiple measurements were abandoned. For the mixtures with 70 %, 80 % and 90 % cellulose, respectively, a run of six tests was performed. The highest value of burning rate within these tests is relevant for evaluation.

The mixture with 90 % cellulose and 10 % test substance showed the maximum burning rate. The burning rate of this mixture (2.33 mm/s) was lower than the maximum burning rate of the reference mixture (2.41 mm/s).

Consequently, the test substance WO2 (tungsten dioxide) has not to be considered as an oxidising substance.

Interpretation of results:

other: no oxidising properties

Remarks:

Migrated information

Conclusions:

WO2 (tungsten dioxide) has not to be considered as an oxidising substance.

Executive summary:

The objective of the study was to provide information on oxidising properties of the inorganic test substance WO2 (tungsten dioxide) for regulatory purposes. WO2 was in accordance with EU method A.17.

Mixtures of the test substance and cellulose were prepared containing 10 to 90 % weight of the test substance in 10 % increments, and for each mixture a pile was formed. One end of the pile was ignited with the flame and the time of reaction over a distance of 200 mm was measured after the reaction zone had propagated an initial distance of 30 mm.

The mixture with 90 % cellulose and 10 % test substance showed the maximum burning rate. The burning rate of this mixture (2.33 mm/s) was lower than the maximum burning rate of the reference mixture (2.41 mm/s).

Consequently, the test substance WO2 (tungsten dioxide) has not to be considered as an oxidising substance.

Description of key information

The objective of the study was to provide information on oxidising properties of the inorganic test substance WO2 (tungsten dioxide) for regulatory purposes. WO2 was in accordance with EU method A.17. Mixtures of the test substance and cellulose were prepared containing 10 to 90 % weight of the test substance in 10 % increments, and for each mixture a pile was formed. One end of the pile was ignited with the flame and the time of reaction over a distance of 200 mm was measured after the reaction zone had propagated an initial distance of 30 mm.The mixture with 90 % cellulose and 10 % test substance showed the maximum burning rate. The burning rate of this mixture (2.33 mm/s) was lower than the maximum burning rate of the reference mixture (2.41 mm/s). Consequently, the test substance WO2 (tungsten dioxide) has not to be considered as an oxidising substance.

Key value for chemical safety assessment

Oxidising properties:

no

Justification for classification or non-classification

The test substance WO2 (tungsten dioxide) has not to be considered as an oxidising substance, therefore no classification is warranted.