[4-[α-[4-(dimethylamino)phenyl]benzylidene]cyclohexa-2,5-dien-1-ylidene]dimethylammonium acetate

Explosiveness

Link to relevant study record(s)

Reference

Endpoint:

explosiveness

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2005, July and August

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study complete and well described, no GLP compliance Read across from a similar substance which has the same main component and with a different counter ion that doesn't influence the characteristics related to the specific end-point

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: internal guideline: VDI 2263 Part 1.

Deviations:

no

Principles of method if other than guideline:

The test was performed as stipulated in test procedure VDI 2263, Part 1. First was made a screening test on burning behaviour and then were performed some tests: impact sensitivity, decomposition behaviour, grewer testing and dust explosibility.

GLP compliance:

no

Parameter:

other: More sensitive to shock than m-dinitrobenzene

Remarks:

migrated information

Remarks on result:

not measured/tested

Parameter:

other: More sensitive to friction than m-dinitrobenzene

Remarks:

migrated information

Remarks on result:

not measured/tested

Parameter:

other: Explosive under influence of flame

Remarks:

migrated information

Remarks on result:

positive (not further specified)

Parameter:

other: Explosive (not specified)

Remarks:

migrated information

Remarks on result:

positive (not further specified)

Impact sensitivity

This test was carried out using the dried sample. Its purpose is to determine whether a sudden impact is capable of initiating a decomposition or an explosion of the sample. Such testing does not conform with the requirements of the German Explosives Act. In case of a positive result, further testing is necessary. The sample is subjected to an impact of about 40 J. The test is repeated until a positive reaction is observed, with a maximum of 10 attempts.

Result: the substance is not impact sensitive when tested according to the above-mentioned procedure.

Decomposition behaviour

Exothermic decomposition behaviour is tested by Differential Thermal Analysis (DTA) according to VDI 2263, Part 1. The sample is heated in a closed glass container at a linear rate of 3 K/min. The temperature difference between sample and reference (Al²O³) is measured as a function of temperature. The measurement is recorded electronically.

Result: An exothermic reaction with a heat release of about -95 J/g was found (onset: 153 °C). Directly before and after this exothermic reaction endothermic reactions were detected. Addition of steel (V4A) did not cause any significant changes in the thermal behaviour.

Comment: The temperature determined as the start of an exothermic decomposition is suitable only as a rough estimate and for comparison purposes. It cannot be used in all cases as the basis for the establishment of safe operating conditions.

Dust explosivity

The test was performed as stipulated in test procedure VDI 2263, Part 1. The dried, fine-grained test sample was inserted into the modified Hartmann tube and dispersed with a blast of air. The dust concentration was varied, and the reaction behaviour was visually observed using the referenced ignition sources.

Results:

Concentration	Ignition source Induction spark
30 g/m^3	0 0 0
100 g/m^3	0 + 0
200 g/m^3	0 + +
500 g/m^3	+ 0 +
1000 g/m^3	+ + 0

0: no ignition

+: ignition, explosion

!: violent explosion

The test substance is classified as dust explosive

Interpretation of results:

non explosive

Remarks:

Migrated information

Conclusions:

Impact sensitivity: not impact sensitive.
Decomposition behaviour: onset 153°C an exothermic reaction with a heat release of about -95 J/g
Dust explosivity only occurs in concentrations ≥ 100 g/m³

Executive summary:

The test was performed as stipulated in test procedure VDI 2263, Part 1. Before testing, the sample was dried to mass constancy. The particle size was determined microscopically. The particle size was = 63 μm. First was made a screening test on burning behaviour and then were performed some tests: impact sensitivity, decomposition behaviour, grewer testing and dust explosivity.

The report is developed on Malachite Green 4; read across between chloride, oxalate and acetate salts form of Malachite Green have the same main component and have a different counter ion that doesn't influence the characteristics related to the specific end-point.

Results:

Impact sensitivity: not impact sensitive.

Decomposition behaviour: onset 153°C an exothermic reaction with a heat release of about -95 J/g

Dust explosibility only occurs in concentrations ≥ 100 g/m³

Conclusion:

The test substance is considered as non explosive.

Description of key information

Non explosive

Key value for chemical safety assessment

Explosiveness:

non explosive

Additional information

Results show that Malachite Green (MG) has no impact sensitivity and an exothermic reaction occurs with onset at 153°C. Regarding dust explosive risk, it only occurs in concentrations ( ≥ 100 g/m³) which are not relevant for handling in the dye facilities; these concentrations are only relevant for spray drying. For this procedure special measures are taken if critical concentrations could be reached. In conclusion MG is considered non explosive.

Justification for classification or non-classification

Malachite Green Acetate (MGA) does not meet the criteria to be considered as explosive.

According to CLP regulation (EC1272/2008) MGA has to be classified as NON explosive.