2,2'-azobis[2-methylbutyronitrile]

Flammability

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

flammable solids

Data waiving:

study technically not feasible

Justification for data waiving:

the study does not need to be conducted for self-reactive substances

Interpretation of results:

not classified based on GHS criteria

Reference 2

Endpoint:

pyrophoric solids

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is known to be stable in contact with air at room temperature for prolonged periods of time (days) and hence, the classification procedure does not need to be applied

Interpretation of results:

not classified based on GHS criteria

Reference 3

Endpoint:

self-heating substances / mixtures

Data waiving:

study technically not feasible

Justification for data waiving:

the study does not need to be conducted for self-reactive substances

Interpretation of results:

not classified based on GHS criteria

Reference 4

Endpoint:

substances / mixtures which in contact with water emit flammable gases

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the experience in production or handling shows that the substance does not react with water, e.g. the substance is manufactured with water or washed with water

Interpretation of results:

not classified based on GHS criteria

Description of key information

The endpoint is waived: The method is not applicable because according to the ECHA guidance in the application of CLP criteria, self reactives should not be considered for classification as flammable solids since flammability is an intrinsic hazard in this class. 2,2'-Azodi(2-methylbutyronitrile is a Self Reactive, Type D.
The classification of self reactives into one of the seven categories of “Types A to G” is given in decision logic Figure 2.81. of CLP, based on the test series A to H, as described in the Part II of the UN-MTC.

Key value for chemical safety assessment

Flammability:

not classified

Additional information

According to ECHA Guidance to CLP flammability of solids (test A10) is not relevant for self reactives as they should not be classified as flammable solid, since flammability is an intrinsic hazard of self reactives;

Test A12: water reactivity: Based on the molecular structure as well as experience in handling and use shows that the substance has no water reactive properties. 

 Test A13: pyrophoric properties:   Based on the molecular structure as well as experience in handling and use shows that the substance has no pyrophoric properties.

According to Guidance on information requirements and chemical safety assessment, R7a, Endpoint specific guidance, R.7.1.10.7, the UN Test method N.4, for self-heating substances and mixtures does not need to be conducted as the substance is classified as self reactive.

According to chapter 2.8 of the CLP regulation, self reactives are thermally unstable substances or mixtures, which can undergo exothermic self-accelerating decomposition. In addition, they can have one or more of the following properties:

(i) be liable to explosive decomposition;

(ii) burn rapidly;

(iii) be sensitive to impact or friction;

(iv) react dangerously with other substances.

A self reactive is regarded as possessing explosive properties when in laboratory testing the mixture (formulation) is liable to detonate, to deflagrate rapidly or to show a violent effect when heated under confinement.

The classification of a self reactive in one of the seven categories “Types A to G” is dependent on its detonation, thermal explosion and deflagrating properties, its response to heating and the concentration

Justification for classification or non-classification

Based on the results of the UN-MTC tests (below) and the decision logic, 2,2'-Azodi(2-methylbutyronitrile) is a Self Reactive, Type D.

Substance name	CAS		max. concentration
2,2'-Azodi(2-methylbutyronitrile)	13472 -08 -7		100%
Phys-chem UN testing	UN test method	Concentration	Evaluation and Results	Reference*
Propagation of detonation test series A	A.2, TNO 50/70 steel tube test	100%	18 cm, No	UN Manual of Tests and Criteria
Propagation of deflagration test series C	C.1, Time/Pressure test	100%	41 ms, Yes slowly	AN data
	C.2, Deflagration test	100%	0 mm/s, No	AN data
Effect of heating under defined confinement test series E	E.1, Koenen test	100%	<1.0 mm, No/low	AN data
	E.2, Dutch pressure vessel test	100%	12.0 mm, Violent	AN data
Explosive power test series F	F.3, Trauzl Test	100%	Test not needed for Type D
Self Accelerating Decomposition Temperature (SADT) test series H	H.4, Heat accumulation storage test (400 ml Dewar vessel)	100%	45 ºC	AN data
*All Data are Company Data/ UN Test Manual
Self-reactive substance, solid, Type D, temperature controlled, UN 3236