Sodium azide

Flammability

Link to relevant study record(s)

Reference

Reference 1

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

Reference 2

Endpoint:

pyrophoric liquids

Data waiving:

study technically not feasible

Justification for data waiving:

the study does not need to be conducted because the substance is a solid

Reference 3

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 substance is known to be soluble in water to form a stable mixture

Reference 4

Endpoint:

flammable gases

Data waiving:

study technically not feasible

Justification for data waiving:

the study does not need to be conducted because the substance is a solid

Reference 5

Endpoint:

flammable solids

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-01-13

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

EU Method A.10 (Flammability (Solids))

Deviations:

no

GLP compliance:

no

Specific details on test material used for the study:

Chemical Name: sodium azide, NaN3
CAS No.: 26628-22-8
Molar mass: 65.01 g/mol
Molecular formula: N3Na
Physical state: solid
Purity: 99.3%
Bulk density: 0.86 g/ml
Origin of the sample(s): Island Veer Chemie Private Ltd.
Lot. No. of vendor: SA0801149
Raw material code: R1024
Lot No.: R1024-0077

Test procedure:

burning rate test: preliminary screening test

Remarks on result:

other: The substance cannot be ignited by ferrocerium sparks. A match or the hot flame of a small gas burner is capable to ignite the substance. After ignition it burns unsteadily with a small yellow flame, white fume, and partially sparkling.

Key result

Test procedure:

other: Burning rate test over 200 mm length

Burning time:

600 s

Remarks on result:

other: The pile was ignited at one end with a hot flame of a small gas burner within 15 seconds. After ignition the substance burns slowly, partially incomplete, and with some sparkling.

PRELIMINARY SCREENNG TEST:

The substance cannot be ignited by ferrocerium sparks. A match or the hot flame of a small gas burner is capable to ignite the substance. After ignition it burns unsteadily with a small yellow flame, white fume, and partially sparkling.

BURNING RATE TEST:

The pile was ignited at one end with a hot flame of a small gas burner within 15 seconds. After ignition the substance burns slowly, partially incomplete, and with some sparkling. For a length of 200 mm a burning time of 10 min was measured.

The substance has not to be considered as a flammable solid.

Interpretation of results:

GHS criteria not met

Conclusions:

Sodium azide can be ignited with a match or a gas burner flame. In the main test, the burning time for a 200 mm pile was 10 minutes. According to the test guideline, a substance can be considered as not flammable, if the burning time exceeds 4 minutes for a 200 mm distance. Moreover, no further testing is then required.

Executive summary:

The flammability of sodium azide was tested according to EU method A.10 (Flammability (solids)). This comprises a preliminary test in which the test substance is tried to be ignited by spark or flame, and a main test, in which a defined pile of the test substance (250 x 20 x 10 mm, triangular profile) is ignited at the one end and the burning rate over a 200 mm distance is measured.

Sodium azide could be ignited by use of a gas burner flame or a match, but not by a ferrocerium spark.

The burning time for a 200 mm distance of sodium azide was measured to be 10 minutes. According to the test guideline, a substance can be considered as not flammable, if the burning time exceeds 4 minutes for a 200 mm distance, which is the case for sodium azide.

Description of key information

The flammability of sodium azide was tested according to EU method A.10 (Flammability (solids)). This comprises a preliminary test in which the test substance is tried to be ignited by spark or flame and a main test, in which a defined pile of the test substance (250 x 20 x 10 mm, triangular profile) is ignited at the one end and the burning rate over a 200 mm distance is measured.

Sodium azide could be ignited by use of a gas burner flame or a match, but not by a ferrocerium spark.

The burning time for a 200 mm distance of sodium azide was measured to be 10 minutes. According to the test guideline, a substance can be considered as not flammable, if the burning time exceeds 4 minutes for a 200 mm distance, which is the case for sodium azide.

Key value for chemical safety assessment

Flammability:

not classified

Justification for classification or non-classification

The burning time for a 200 mm distance of sodium azide was measured to be 10 minutes. According to the test guideline, a substance can be considered as not flammable, if the burning time exceeds 4 minutes for a 200 mm distance, which is the case for sodium azide.