Tetrakis(phenylmethyl)thioperoxydi(carbothioamide)

Oxidising properties

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

oxidising solids

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

unsuitable test system

Remarks:

Oxidizing properties of the substance are not evident from the chemical structure which contains no oxygen. Based on a second study with an inorganic carrier and under exclusion of air it was concluded that the results of the first study are false positive.

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Contact with:

powdered cellulose

Sample tested:

test mixture (not specified)

Parameter:

maximum burning rate

Result:

3.57 mm/s

Sample tested:

reference mixture (not specified)

Parameter:

maximum burning rate

Result:

1.15 mm/s

Interpretation of results:

other: oxidising

Remarks:

Migrated information

Conclusions:

Organic peroxide: No

Reference 2

Endpoint:

oxidising solids

Type of information:

experimental study

Adequacy of study:

key study

Study period:

September 26, 1989 to May 5, 1990

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Guideline study performed in compliance with GLP, available as unpublished report, no restrictions, fully adequate for assessment.

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

other: Directive 84/449/EEC, Annex V, A.17 (Extended)

GLP compliance:

yes

Key result

Sample tested:

test mixture (not specified)

Parameter:

maximum burning rate

Result:

<= 1.85 mm/s

Sample tested:

reference mixture (not specified)

Parameter:

maximum burning rate

Result:

1.22 mm/s

Interpretation of results:

other: no oxidising properties

Conclusions:

According to the structural formula of TBzTD (summary formula: C30H28N2S4) there is no indication why TBzTD could have oxidizing properties. The TBzTD molecule does not contain functional groups which could release oxygen or other oxidizing agents.

This conclusion is experimentaly confirmed by testing TBzTD in nitrogen atmosphere where it does not burn. The supposed oxidizing behaviour of TBzTD is caused by its incineration when finely distributed on a supporting material. During the standard test for oxidizing properties cellulose acts as a carrier which supports the burning of TBzTD. A mixtues of TBzTD and silicon dioxide shows a higher flame propagation speed then the mixture of TBzTD and cellulose what shows that the buring cannot be interpreted by an oxidizing behaviousr of TBzTD.

Testing TBZTD (pure) on flammability shows that it is not flammable, due to the low melting point of the product (in the range of 129 -133°C). Therefore TBZTD has not to be classified as a flammable solid.

Executive summary:

Tetrabenzylthiuram disulfide (TBZTD) is determined having oxidizing properties by RCC Notox B. V. (Report RCC Notox B. V 0808/C624, April 14, 1989). The result of this investigation was reproduced by the Safety Department of Akzo Chemicals Nederland B.V. at Deventer.

According to the structural formula of this product (summary formula: C₃₀H₂₈N₂S₄), however, it is not possible that it would have oxidizing properties. The product does not contain functional groups in the molecule, by which oxygen or other oxidizing agents can be released, e.g. such as by products as KCIO₃.

This conclusion is confirmed by the result of testing TBZTD having oxidizing properties, in nitrogen atmosphere, where it does not show burning behaviour. The burning behaviour during the test in air is caused by the flammability of the product itself, what is only possible if it is mixed up with a support. During the oxidizing properties test, the present cellulose acts as a support.

Testing TBZTD (pure) on flammability shows that it is not flammable, due to the low melting point of the product (in the range of 129 -133°C). Therefore TBZTD has not to be classified as a flammable solid. The judgement of the tests on TBZTD was discussed with Mr Schlieper of the BAM (Bundesanstalt für Materialprufung und -forschung, Berlin, Germany), who supported the final conclusions.

Description of key information

The substances does not support the burning in the absence of air.

Key value for chemical safety assessment

Oxidising properties:

no

Additional information

TBzTD showed oxidizing properties in a first study in the sense that it can sustain a reaction with cellulose, at a burning rate higher than that of the reference mixture. Since the oxidizing properties could not be explained by the molecular structure of the test substance the test was repeated under modified conditions. The burning rates obtained for mixtures of the substance and Kieselguhr were higher than those obtained for the substance and cellulose. This indicated that the burning rates for the substance and cellulose were caused by the flammable properties of the substance and not by oxidation. A 60/40 mixture of substance and cellulose was also tested under a nitrogen atmosphere and did not burn.

Justification for classification or non-classification

In the presence of air and either mixed with organic cellulose or inorganic Kieselgur the substance burns. This is not caused by oxidizing properties of the substance since it does not contain oxygen or other oxidizing groups and it does not support burning when mixed with cellulose and incinerated in the absence of air. An oxidizing classification is therefore not warranted.