Chromium diboride

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)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Contact with:

powdered cellulose

Sample tested:

4:1 sample-to-cellulose ratio

Parameter:

mean burning time

Result:

> 180 s

Sample tested:

1:1 sample-to-cellulose ratio

Parameter:

mean burning time

Result:

> 180 s

Sample tested:

reference: 3:7 mixture potassium bromate + cellulose

Parameter:

mean burning time

Result:

116 s

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:

The test item contains residual moisture of < 0.1 wt.-%, which was determined by drying the test item under vacuum.

The reference item Potassium Bromate contains residual moisture of < 0.1 wt.-%, which was determined by drying the test item under vacuum.

The reagent Cellulose contains residual moisture of 7.0 wt. -%, which was determined by drying the test item under vacuum.

Interpretation of results:

GHS criteria not met

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 test the test item CrB2 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 chromium diboride has been conducted according to UN Regulation Test O.1 (2009) by evaluating the burning times of mixtures of chromium diboride in the rations of 4:1 and 1:1. The results were then compared to the reference mixture consisting of potassium bromate and cellulose (ratios 3:7).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.

The recording of burning times were taken from the time power was applied to the heating wire until the end of occurring main reactions such like inflammation, incandescence or glowing combustion. Five replications were performed for each test/reference mixture.

The burning time of 4:1 and 1:1 mixtures of chromium diboride and cellulose was higher than the burning time of the reference mixture with ratio 3:7. In accordance with the results obtained in UN Test O.1 (Oxidising Properties, Solids) the test item is classified as follows:

-non-oxidizing solid according to UN Transport Regulation (Division 5.1)

-non-oxidizing solid according to GHS and EC 1272/2008 (CLP Regulation) Annex 1:2.14

Description of key information

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 reference mixture of Potassium bromate and cellulose (3:7). Due to the test the test item CrB2 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

Additional information

The testing of the oxidizing properties of Chromium diboride has been conducted according to UN Regulation Test O.1 (2009) by evaluating the burning times of mixtures of Chromium diboride in the rations of 4:1 and 1:1. The results were then compared to the reference mixture consisting of Potassium bromate and cellulose (ratios 3:7). 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.

The recording of burning times were taken from the time power was applied to the heating wire until the end of occurring main reactions such like inflammation, incandescence or glowing combustion. Five replications were performed for each test/reference mixture.

The burning time of 4:1 and 1:1 mixtures of Chromium diboride and cellulose was higher than the burning time of the reference mixture with ratio 3:7. In accordance with the results obtained in UN Test O.1 (Oxidising Properties, Solids) the test item is classified as follows:

- non-oxidizing solid according to UN Transport Regulation (Division 5.1)

- non-oxidizing solid according to GHS and EC 1272/2008 (CLP Regulation) Annex 1:2.14.

Justification for classification or non-classification

The oxidizing properties of Chromium diboride were tested according to UN Regulation Test O.1 (2009). The test revealed, that the burning times of the mixtures of the test item with cellulose were higher than the one of the reference mixture (Potassium bromide:cellulose 3:7). In accordance with these results the test item does not warrant classification as oxidizing solid according to UN Transport Regulation (Division 5.1), GHS and EC 1272/2008 (CLP Regulation) Annex 1:2.14.