Carbon black

Oxidising properties

Link to relevant study record(s)

Reference

Endpoint:

oxidising solids

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15.07.2020 - 14.09.2020

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)

Version / remarks:

ST/SG/AC.10/11/Rev.6, 2015, 34.4.1), SOP SPZ 104

Principles of method if other than guideline:

In this test well defined mixtures of the test substance and of the reference substances with cellulose are formed to a defined conical pile. After electrical ignition on a plate with low thermal conductivity the mean burning time from five trials is determined. If the mean burning time of the substance mixture with cellulose (lowest of the two ratios 4:1 and 1:1) is less than that of a 3:7 mixture of potassium bromate with cellulose, the criterion for Div. 5.1 is fulfilled. In this case further reference mixtures (2:3 and 3:2 ratios of potassium bromate with cellulose) have to be tested in order to find the assignment of the substance to the different packing groups (PG I – PG III) in Div. 5.1.

GLP compliance:

no

Other quality assurance:

ISO/IEC 17025 (General requirements for the competence of testing and calibration laboratories)

Contact with:

powdered cellulose

Key result

Sample tested:

reference: 3:7 mixture potassium bromate + cellulose

Parameter:

mean burning time

Result:

124 s

Remarks on result:

other: mean burning time from five trials

Remarks:

(120 + 132 + 127+ 115+ 126)/5

Key result

Sample tested:

1:1 sample-to-cellulose ratio

Parameter:

mean burning time

Result:

> 180 s

Remarks on result:

other: Burning with the appearance of flames was observed until the reaction was terminated at times > 180 > 180 > 180 > 180 > 180 s, respectively.

Key result

Sample tested:

4:1 sample-to-cellulose ratio

Parameter:

mean burning time

Result:

> 180 s

Remarks on result:

slow smouldering

Remarks:

There was no flame was noted; only smoke development was observed. After > 180 > 180 > 180 > 180 > 180 seconds, respectively, the reaction was terminated.

Interpretation of results:

GHS criteria not met

Conclusions:

Carbon Black (CORAX N990 BEADS) is not an oxidizing substance of Div. 5.1.

Executive summary:

Carbon Black (CORAX N990 BEADS) was subjected to testing for oxidizing potential in accordance with the test method UN O.1. After electrical ignition on a plate with low thermal conductivity, the mean burning time from five trials is determined. If the mean burning time of the substance mixture with cellulose (lowest of the two ratios 4:1 and 1:1) is less than that of a 3:7 mixture of potassium bromate with cellulose, then the criterion for Div. 5.1 is fulfilled. For the mixtures in a mass ratio of 1: 1, burning with the appearance of flames was observed until the reaction was terminated at times  > 180 > 180 > 180 > 180 > 180 s, respectively. For the mixtures in a mass ratio of 4: 1, no flame was noted; only smoke development was observed. After  > 180 > 180 > 180 > 180 > 180 seconds, respectively, the reaction was terminated. The reference substance had a burning time average of 124 s. The average burning times for the 1: 1 and 4: 1 mixtures with cellulose powder were (significantly) longer than the average burning time of the mixture of potassium bromate: cellulose powder in a mass ratio of 3: 7. The conditions for classification in accordance with Div 5.1 are not met.

Description of key information

Carbon Black (CORAX N990 BEADS) was subjected to testing for oxidizing potential in accordance with the test method UN O.1. After electrical ignition on a plate with low thermal conductivity, the mean burning time from five trials is determined. If the mean burning time of the substance mixture with cellulose (lowest of the two ratios 4:1 and 1:1) is less than that of a 3:7 mixture of potassium bromate with cellulose, then the criterion for Div. 5.1 is fulfilled. For the mixtures in a mass ratio of 1: 1, burning with the appearance of flames was observed until the reaction was terminated at times  > 180 > 180 > 180 > 180 > 180 s, respectively. For the mixtures in a mass ratio of 4: 1, no flame was noted; only smoke development was observed. After  > 180 > 180 > 180 > 180 > 180 seconds, respectively, the reaction was terminated. The reference substance had a burning time average of 124 s. The average burning times for the 1: 1 and 4: 1 mixtures with cellulose powder were (significantly) longer than the average burning time of the mixture of potassium bromate: cellulose powder in a mass ratio of 3: 7. The conditions for classification in accordance with Div 5.1 are not met.

Key value for chemical safety assessment

Oxidising properties:

non oxidising

Justification for classification or non-classification

Non-nanoforms of carbon black has no oxidising potential. The mean burning times of the investigated mixtures of sample and cellulose were essentially significantly greater than that of the reference mixture (3:7) of potassium bromate with cellulose. A classification is therefore not warranted.