Disodium [2-hydroxy-3-[(2-hydroxy-1-naphthyl)azo]-5-nitrobenzene-1-sulphonato(3-)][1-[(2-hydroxy-4-nitrophenyl)azo]-2-naphtholato(2-)]chromate(2-)

Explosiveness

Link to relevant study record(s)

Reference

Endpoint:

explosiveness, other

Type of information:

other: Expert statement

Adequacy of study:

key study

Study period:

2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Expert statement

Justification for type of information:

None

Qualifier:

according to guideline

Guideline:

other: Expert Statement

Principles of method if other than guideline:

None

GLP compliance:

no

Specific details on test material used for the study:

None

Key result

Parameter:

other: The calculated chemical oxygen balance is above the trigger value of -200, but the determination of the exothermic decomposition energy demonstrated an energy release far below the critical value of 500 J/g.

Remarks on result:

not measured/tested

Screening evaluation

No experimental test data according to EU Method A.14 or comparable methods for Acid Black 207 are available.

Considering that explosive properties are associated with the presence of certain chemical groups in the molecule, a screening evaluation can be conducted aimed to identify the presence of such reactive groups within the molecular structure harvesting the capability for a rapid high energy release.

According to CLP Regulation examples of groups which may indicate explosive properties are:

-       C-C unsaturation (e.g. acetylenes, acetylides, 1,2-dienes);

-       C-Metal, N-Metal (e.g. Grignard reagents, organo-lithium compounds);

-       Contiguous nitrogen atoms (e.g. azides, aliphatic azo compounds, diazonium salts, hydrazines, sulphonylhydrazides);

-       Contiguous oxygen atoms (e.g. peroxides, ozonides);

-       N-O (e.g. hydroxyl amines, nitrates, nitro compounds, nitroso compounds, N-oxides, 1,2-oxazoles);

-       N-halogen (e.g. chloramines, fluoroamines);

-       O-halogen (e.g. chlorates, perchlorates, iodosyl compounds).

Analysis of the above depicted molecular structure revealed, that one azo group representing a chemical alert structure for explosive properties is present in the molecule.

Calculation of the oxygen balance according to the above mentioned formula is -118.69 and therefore higher than the trigger value of -200.

Determination of the exothermic decomposition energy

In order to assess if the substance Acid Black 207 possesses the potential to rapidly release huge amounts of energy a thermal analysis (Differential Scanning Calorimetry) has been performed at the Analytical Department Huntsman Textile Effects (Germany) GmbH. The results of the measurement are shown in Annex 1.

The curve displays one exothermic peak between 320 °C and 350 °C with a total energy release of 408.29 J/g which is considered to represent substance decomposition. As a result, the overall energy release is below a critical trigger level of 500 J/g and the onset of energy release is below 500 °C.

Interpretation of results:

unstable explosive based on GHS criteria

Conclusions:

In summary, analysis of the chemical structure reveals two azo groups representing chemical alert structures for explosive properties are present in the molecule. The calculated chemical oxygen balance is above the trigger value of -200, but the determination of the exothermic decomposition energy demonstrated an energy release far below the critical value of 500 J/g. Therefore, the substance is considered to be non-explosive according to Directive 67/548/EEC and Regulation (EC) 1272/2008 and no further testing is required.

Executive summary:

No experimental test data according to EU Method A.14 or comparable methods for Acid Black 207 are available. In summary, analysis of the chemical structure reveals two azo groups representing chemical alert structures for explosive properties are present in the molecule. The calculated chemical oxygen balance is above the trigger value of -200, but the determination of the exothermic decomposition energy demonstrated an energy release far below the critical value of 500 J/g. Therefore, the substance is considered to be non-explosive according to Directive 67/548/EEC and Regulation (EC) 1272/2008 and no further testing is required.

Description of key information

In order to assess if the substance Acid Black 207 possesses the potential to rapidly release huge amounts of energy a thermal analysis (Differential Scanning Calorimetry) has been performed at the Analytical Department of Huntsman Textile Effects (Germany) GmbH. The results of the measurement are shown in Annex 1 to the expert statement. The curve displays no exothermic peak up to 350 °C. As a result, the overall energy release is below a critical trigger level of 500 J/g and the onset of energy release is below 500 °C. In summary, analysis of the chemical structure reveals two azo groups representing chemical alert structures for explosive properties are present in the molecule. The calculated chemical oxygen balance is above the trigger value of -200, but the determination of the exothermic decomposition energy demonstrated an energy release far below the critical value of 500 J/g. Therefore, the substance is considered to be non-explosive according to Directive 67/548/EEC and Regulation (EC) 1272/2008 and no further testing is required.

Key value for chemical safety assessment

Explosiveness:

non explosive

Justification for classification or non-classification

In accordance with Column 2 of section 7.11 of REACH Annex VII, the full study has not been conducted as there are no chemical groups associated with explosive properties present in the substance.