Phenol, 4-[[4-(dimethylamino)phenyl]azo]-, reaction products with sodium sulfide (Na2(Sx)), leuco derivatives

Oxidising properties

Link to relevant study record(s)

Reference

Endpoint:

oxidising solids

Type of information:

experimental study

Adequacy of study:

key study

Study period:

30 June - 18 October, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

31 May 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Expiry date 01 December 2020

Contact with:

other: Oxidiser cellulose mixtures containing 10 to 90 % weight of oxidiser in 10 % increments were prepared. Based on sponsor’s suspicion that the result is a false positive the test was repeated using kieselguhr in place of cellulose.

Duration of test (contact time):

423 s

Key result

Sample tested:

other: Oxidiser cellulose mixtures containing 10 to 90 % weight of oxidiser in 10 % increments were prepared;test was repeated using kieselguhr in place of cellulose.test was repeated using kieselguhr in place of cellulose.

Remarks:

burning time: 399sec

Parameter:

burning time of reaction over a distance of 200 mm

Result:

0.501 mm/s

Remarks on result:

other: In the course of the Main Test burning rate of the mixture containing 10% test item was higher than the highest burning rate of the reference mixture.

Remarks:

Therefore Leuco Sulfur Blue 9 is considered to be an oxidizing substance, under these testing conditions. The test was repeated with kieselguhr in place of cellulose. These mixtures did not burn.

Key result

Sample tested:

other: Oxidiser cellulose mixtures containing 10 to 90 % weight of oxidiser in 10 % increments were prepared;test was repeated using kieselguhr in place of cellulose.test was repeated using kieselguhr in place of cellulose.

Remarks:

burning time: 381sec

Parameter:

burning time of reaction over a distance of 200 mm

Result:

0.525 mm/s

Remarks on result:

other: In the course of the Main Test burning rate of the mixture containing 10% test item was higher than the highest burning rate of the reference mixture.

Remarks:

Therefore Leuco Sulfur Blue 9 is considered to be an oxidizing substance, under these testing conditions. The test was repeated with kieselguhr in place of cellulose. These mixtures did not burn.

Reference measurement

Ratio Ba(NO3)2: Cellulose	Weight Ba(NO3)2(g)	Weight Cellulose (g)	Burning time (sec)	Burning rate (mm/sec)
10 : 90 %		2.00		18.01		469		0.426
20 : 80 %		4.02		16.01		406		0.493
30 : 70 %		6.04		14.02		395		0.506
40 : 60 %		12.00		18.01		439		0.456
50 : 50 %		15.02		15.00		503		0.398
60 : 40 %		18.01		12.01		563		0.355
70 : 30 %		21.01		9.00		638		0.313
80 : 20 %		40.00		10.02		-		-
90 : 10 %		45.00		5.03		-		-

 

 

Main Test

Ratio Test item : Cellulose	Weight Test item (g)	Weight Cellulose (g)	Burning time (sec)	Burning rate (mm/sec)	Type of burning
10 : 90 %	2.00	18.06	423	0.473	ignited, burnt with flame
20 : 80 %		4.03		16.06		467		0.428		ignited, burnt with flame
30 : 70 %	6.01	13.99	-	-	ignited, did not pro-pagate over 200 mm
40 : 60 %		12.01		18.03		-		-		ignited, did not pro-pagate over 200 mm
50 : 50 %	15.01	14.99	-	-	ignited, did not pro-pagate over 200 mm
60 : 40 %	18.00	12.03	-	-	ignited, did not pro-pagate over 200 mm
70 : 30 %	14.00	6.00	-	-	ignited, did not pro-pagate over 200 mm
80 : 20 %	16.04	4.05	-	-	ignited, did not pro-pagate over 200 mm
90 : 10 %	18.03	2.06	-	-	ignited, but the flame went out

 

 

Results of the repeated tests with the mixture containing 10% test item

Ratio Test item : Cellulose		Weight Test item (g)		Weight Cellulose (g)		Burning time (sec)		Burning rate (mm/sec)
10 : 90 %		2.03		18.01		399		0.501
10 : 90 %		2.01		18.00		381		0.525

 

 

Trials with test item –kieselguhrmixtures

Ratio Test item : Kieselguhr	Weight Test item (g)	Weight Kieselguhr(g)	Burning time (sec)	Burning rate (mm/sec)	Type of burning
10 : 90 %	2.03	18.06	-	-	no ignition
20 : 80 %	4.00	16.02	-	-	no ignition
30 : 70 %	6.01	14.02	-	-	no ignition
40 : 60 %	12.02	18.02	-	-	no ignition
50 : 50 %	15.00	14.99	-	-	no ignition
60 : 40 %	18.00	12.01	-	-	no ignition
70 : 30 %	14.05	6.06	-	-	no ignition
80 : 20 %	16.00	3.99	-	-	ignited, but the flame went out
90 : 10 %	18.03	2.00	-	-	ignited, but the flame went out

Interpretation of results:

GHS criteria not met

Conclusions:

The cone-shaped pile formed during the Preliminary Test was ignited, but the flame went out. The reaction was not vigorous; therefore the Main Test was performed. The highest value of burning rate of a given mixture is relevant for evaluation.
In the course of the Main Test burning rate of the mixture containing 10% test item was higher than the highest burning rate of the reference mixture. Therefore Leuco Sulfur Blue 9 should be considered as oxidizing under these testing conditions. The details (contents of the mixtures and the burning times) are summarized in Tables 1, 2 and 3. Based on the manufacturing process and chemical structure of the substance, this result was however deemed as a false positive.

As stated in method A.17 of EC Regulation 40/2008, section 1.6.2.2 the test was repeated with kieselguhr in place of cellulose. These mixtures did not burn. Then it is concluded that the test item Leuco Sulfur Blue 9 is not considered as an oxidizing substance

Executive summary:

The purpose of this study was to investigate the oxidising properties of the test item.

No further testing is required when the preliminary test clearly indicates that the substance has oxidising properties. When this is not the case, the substance is subjected to the full test.

In the main test, the substance to be tested and a defined combustible substance were mixed in various ratios. Each mixture was then formed into a pile and the pile ignited at one end. The maximum burning rate determined was compared with the maximum burning rate of the reference mixture. Burning rate of the test mixture containing 10% Leuco Sulfur Blue 9 was found to be higher than the maximum burning rate of the reference mixture.Therefore, Leuco Sulfur Blue 9 is considered to be an oxidizing substance, under these testing conditions.

As the result was suspected of being a false positive, the test was repeated using kieselguhr in place of cellulose.These mixtures did not burn. 

Description of key information

The purpose of this study was to investigate the oxidizing properties of the test item. In the course of the Main Test burning rate of the mixture containing 10% test item was higher than the highest burning rate of the reference mixture. This result was however deemed as a false positive.

 

As stated in method A.17 of EC Regulation 40/2008, section 1.6.2.2 the test was repeated with kieselguhr in place of cellulose. These mixtures could not be ignited. Then it is concluded that the test item Leuco Sulphur Blue 9 is not considered as an oxidizing substance

Key value for chemical safety assessment

Oxidising properties:

non oxidising