Tungsten hexachloride

Oxidising properties

Link to relevant study record(s)

Reference

Endpoint:

oxidising solids

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016-06-22 to 2016-09-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

UN Manual of Tests and Criteria: Test O.1 (Test for oxidizing solids)

GLP compliance:

yes (incl. QA statement)

Contact with:

powdered cellulose

Sample tested:

reference: 3:7 mixture potassium bromate + cellulose

Parameter:

mean burning time

Result:

116 s

Sample tested:

1:1 sample-to-cellulose ratio

Parameter:

mean burning time

Result:

> 180 s

Remarks on result:

other: Slow flameless combustion with formation of smoke, which spread over the whole pile within approx. 360 s.

Sample tested:

4:1 sample-to-cellulose ratio

Parameter:

mean burning time

Result:

> 180 s

Remarks on result:

other: Please see Annotation for 4.1 ratio in "Any other information on results incl. tables".

Annotation for result 4:1 sample-to-cellulose ratio:

Break of wire between 22 to 74 s caused by corrosive decomposition products. The pile only showed a slow flameless combustion with a formation of smoke when the wire was still intact. The decomposition spreads over the whole pile within a period longer than 180 s. Since only a slow flameless combustion could be observed even when the ignition wire was still intact, it can be assumed that this mixture would not have a lower burning time than the reference mixture.

The tests with the mixtures potassium bromate:cellulose 2:3 and 3:2 were not performed, because the burning times of the mixtures of the test item with cellulose were higher than the burning time of the reference mixture 3:7.

Residual moisture:

A small amount of the test item was dried under vacuum at a temperature of 50 °C for 18 hours. During drying the test item changed its colour from dark violet into pink/orange. This can be assigned to decomposition upon contact with humidity. Also a mass loss of approx. 27 % was observed, which was presumably caused by decompostion. The reference item Potassium Bromate contains a residual moisture of < 0.1 wt.-%, which was determined by drying the test item under vacuum. The reagent Cellulose contains a residual moisture of 7.0 wt.-%, which was determined by drying the test item under vacuum.

Interpretation of results:

other: No classifiaction as oxidizing solid.

Conclusions:

The burning time of the mixtures of the test item with cellulose (4:1 and 1:1) is greater than the burning time of the refernce mixture of potassium bromate and cellulose (3:7). Due to the tests the test item tungsten hexachloride does not have to be classified as oxidizing solid according to:
- UN Transport Regulation (Division 5.1)
- GHS and EC 1272/2008 (CLP Regulation) Annex 1: 2.14

Executive summary:

The testing of the oxidizing properties of tungsten hexachloride has been conducted according to UN Test O.1 (2009) by evaluating the burning times of tungsten hexachloride/cellulose mixtures with the ratios of 4:1 and 1:1. The results were then compared to the reference mixture consisting of potassium bromate and cellulose (ratio 3:7). Testings with the mixtures potassium bromate:cellulose 2:3 and 3:2 were not performed, because the burning times of the mixtures of the test item with cellulose were higher than the burning time of the reference mixture potassium bromate:cellulose 3:7.

The burning times were recorded from the time when power was applied to the heating wire until the end of occurring main reactions (e.g. flame, incandescence or glowing combustion). Five replications were performed for each test/reference mixture.

According to the results the test item tungsten hexachloride does not have to be classified as oxidizing solid according to:

-UN Transport Regulation (Division 5.1)

-GHS and EC 1272/2008 (CLP Regulation) Annex 1: 2.14

Description of key information

The burning times of the mixtures of the test item with cellulose (4:1 and 1:1) are greater than the burning time of the refernce mixture of potassium bromate and cellulose (3:7). Due to the tests, the test item tungsten hexachloride does not have to be classified as oxidizing solid according to:

-UN Transport Regulation (Division 5.1)

-GHS and EC 1272/2008 (CLP Regulation) Annex 1: 2.14

Key value for chemical safety assessment

Oxidising properties:

non oxidising