Molybdenum sulfide

Oxidising properties

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

oxidising solids

Type of information:

other: read-across study

Adequacy of study:

supporting study

Study period:

2009-07-14 to 2009-07-21

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)

Remarks:

signed 2004-09-06

Contact with:

powdered cellulose

Duration of test (contact time):

<= 3 min

Sample tested:

reference: 3:2 mixture potassium bromate + cellulose

Parameter:

mean burning time

Result:

21 s

Remarks on result:

other: mean of five tests

Sample tested:

reference: 2:3 mixture potassium bromate + cellulose

Parameter:

mean burning time

Result:

66 s

Remarks on result:

other: mean of five tests

Sample tested:

reference: 3:7 mixture potassium bromate + cellulose

Parameter:

mean burning time

Result:

128 s

Remarks on result:

other: mean of five tests

Sample tested:

1:1 sample-to-cellulose ratio

Parameter:

mean burning time

Result:

221 s

Remarks on result:

other: mean of five tests

Sample tested:

4:1 sample-to-cellulose ratio

Parameter:

mean burning time

Result:

323 s

Remarks on result:

other: mean of five tests

Due to the fact that both mixtures of the test item with cellulose (4:1 and 1:1) have higher mean burning times compared to the reference mixture in the ratio 3:7, it is concluded that the test item has no oxidizing properties.

Interpretation of results:

GHS criteria not met

Conclusions:

The test item molybdenum trioxide does not meet the classification criteria for oxidizing properties in the sense of the Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria, Part 34.4.1 (Test O.1).
The test item molybdenum trioxide does not meet the classification criteria for oxidizing properties in accordance with Regulation (EC) No. 1272/2008 on the classification, labelling and packaging of substances and mixtures ("CLP Regulation").

Reference 2

Endpoint:

oxidising solids

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Description of key information

MoS₂ is a stable and inert substance, unlikely to be an oxidising agent in the sense that this requires a hazard classification (see also justification for classification or non-classification).

Key value for chemical safety assessment

Oxidising properties:

non oxidising

Justification for classification or non-classification

At ambient temperatures and in normal conditions, MoS₂is a stable and inert substance, unlikely to be an oxidising agent in the sense that this requires a hazard classification. A thermite type mixture can be prepared with MoS₂ and elemental magnesium, which may explode on grinding (Bretherick’s Handbook of reactive chemical hazards, Volume 1,7^thedition, 2007). However, in this case, MoS₂ is mixed with a strong reducing agent. In a test for oxidising properties (UN O.1 Test) with the substance molybdenum trioxide, this MoO₃ was not classified for oxidising properties. Since MoO₃ contains Mo in a higher oxidation state (+VI) than MoS₂ (+IV), it can be assumed that MoS₂ would also not classify as a oxidising solid in such a test. In industrial processes MoS₂ itself is oxidised in air in an exothermic reaction to yield MoO₃. In conclusion, and supported by long-term industrial experience in handling, MoS₂ does not require classification as an oxidising solid.