Graphene

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:

06 Feb 2017 - 27 Feb 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: UN Transportation of Dangerous Goods Recommendations, Test N.4

Principles of method if other than guideline:

The cubic sample containers of 25 mm and 100 mm side lengths are employed. They are open at the top and manufactured from stainless-steel net, with a mesh opening of 0.053 mm. Each container is housed in an outer cubic container cover, manufactured from stainless-steel net with a mesh opening of 0.595 mm which is slightly larger than the sample container, so that the container fits in this cover. In order to minimise the effects of air circulation, another stainless-steel cage, manufactured with a mesh opening of 0.595 and 150 x 150 x 250 mm in size, houses both these baskets.
The test material, in its commercial form, is filled to the brim of the sample basket which is then tapped several times. If the sample has been seen to settle then more material is added. The container is housed in the covers and placed in the centre of the oven at the required test temperature.
A hot air, circulating type oven with an inner capacity of approximately 120 litres and capable of controlling the internal temperature at 140 ± 2 °C is utilised. In the initial test (with a 100 mm cube), the oven temperature is raised to 140 °C and held isothermally for a test period of 24 hours. The temperature of the sample and oven are continually monitored / recorded with inconel sheathed thermocouples to provide accurate temperature measurement. One thermocouple is placed in the centre of the sample and the other between the sample container and the oven wall

GLP compliance:

not specified

Specific details on test material used for the study:

As received, the sample is observed to be a black powder. In order to obtain sufficient sample quantity of finer particle size, it was necessary to mechanically mill the material.
Moisture content 7.90 % by weight

Key result

Relative self-ignition temperature:

> 140 °C

Remarks on result:

no self ignition observed under the test conditions

Remarks:

On completion of testing, the sample remained unchanged

Table2 : Detailed UN 4.2 Test Results

Basket Number	Basket Size (mm cube)	Test Temperature (°C)	Test System	Sample Weight (g)	Ignition Yes (Y) / No (N)
1	100	140	10	7.4	N

Conclusions:

No self ignition was observed for the test item graphene under the test conditions, indicating a relative self-ignition temperature > 140°C.

Executive summary:

Auto-ignition temperature of the test item was assessed according to UN Transportation of Dangerous Goods Recommendations, Test N.4. No self ignition was observed for the test item graphene under the test conditions, indicating a relative self-ignition temperature > 140°C.

Description of key information

Auto-ignition temperature of the test item was assessed according to UN Transportation of Dangerous Goods Recommendations, Test N.4. No self ignition was observed for the test item graphene under the test conditions, indicating a relative self-ignition temperature > 140°C.

Key value for chemical safety assessment

Autoflammability / Self-ignition temperature at 101 325 Pa:

140 °C