Sodium azide

Auto flammability

Link to relevant study record(s)

Reference

Endpoint:

relative self-ignition temperature (solids)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-01-12

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

EU Method A.16 (Relative Self-Ignition Temperature for Solids)

Deviations:

yes

Remarks:

: cylindrical instead of cubic test container

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

Key result

Relative self-ignition temperature:

309 °C

Remarks on result:

other:

Remarks:

Test pressure not reported in study report.

The self-ignition temperature of sodium azide was determined according to EU Method A.16. The report deviates from the guideline, as a cylindrical instead of a cubical test container was used; the volume was equal to that stated in the guideline. The oven was heated at 0.5 K/min.

One sample showed an exothermic reaction with a maximum temperature of 411 °C at an oven temperature of 309 °C. The other sample showed an exothermic reaction with a maximum temperature of 630 °C at an oven temperature of 340 °C.

Using a conservative approach, the lower value of the two experiments was used and the self-ignition temperature was therefore 309 °C.

Conclusions:

The self-ignition temperature of sodium azide was tested in two measurements according to the EU Method A.16. The self-ignition temperatures in the two measurements were 309°C and 340°C. Using a conservative approach, the lower value of the two measurements is used and therefore the self-ignition temperature of sodium azide is 309°C.

Executive summary:

The self-ignition temperature of sodium azide was determined according to EU Method A.16. The report deviates from the guideline, as a cylindrical instead of a cubical test container was used; the volume was equal to that stated in the guideline. The oven was heated at 0.5 K/min.

One sample showed an exothermic reaction with a maximum temperature of 411°C at an oven temperature of 309°C. The other sample showed an exothermic reaction with a maximum temperature of 630°C at an oven temperature of 340°C.

Using a conservative approach, the lower value of the two experiments was used and the self-ignition temperature was therefore 309°C.

Description of key information

The self-ignition temperature of sodium azide was determined according to EU Method A.16. The report deviates from the guideline, as a cylindrical instead of a cubical test container was used; the volume was equal to that stated in the guideline. The oven was heated at 0.5 K/min.

One sample showed an exothermic reaction with a maximum temperature of 411°C at an oven temperature of 309°C. The other sample showed an exothermic reaction with a maximum temperature of 630°C at an oven temperature of 340°C.

Using a conservative approach, the lower value of the two experiments was used and the self-ignition temperature was therefore 309°C.

Key value for chemical safety assessment

Autoflammability / Self-ignition temperature at 101 325 Pa:

309 °C