[No public or meaningful name is available]

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:

2021-07-26 - 2021-07-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: • UN Manual of Tests and Criteria, 7th rev. edition, New York and Geneva, 2019: Part III, Section 33, Test N.4 Test method for self-heating substances (UN) and Appendix 6 Screening Procedures, A6.5.3.2 (a) Grewer Oven test

Deviations:

no

GLP compliance:

no

Key result

Relative self-ignition temperature:

> 190 °C

The self-ignition behaviour of the test item was determined in the Grewer Oven according to VDI guideline 2263, part 1. For this purpose, the test item was filled in a small wire basket of a volume of 8 cm³ and this wire-basket was placed in the Grewer Oven. An additional basket was filled with a reference material (graphite) and was also places in the Grewer Oven. For information: in this oven, the self-ignition behaviour of five test items can be determined simultaneously.

The temperature of the oven was increased with a constant heating rate (1.2 K/min) in an air stream of 100 to 120 L/h and the temperature of the sample was recorded as a function of time at intervals of 10 seconds. The self-ignition behaviour of the pure test item was indicated as a deviation between sample temperature and reference temperature.

Very often, the test item melts before a self-ignition takes place. In this case, the sample flows out of the basket and no self-ignition can occur. Thus, the self-ignition behaviour of the sample blended with 50 wt.-% Kieselguhr was investigated in a third wire basket simultaneously. Kieselguhr has a high specific surface area and prevents the test item from flowing out of the baskets.

For the evaluation of the experimental data, the data points were first smoothed using the program PTC MathCad. Afterwards, the smoothed data were fitted by cubical splines with a minimum number of system points. The number of system points for the sample, the sample blended with Kieselguhr and the reference material were minimized by the program. The rate of temperature increase of the analytical polynoms was then analytically calculated.

In the investigation of self-ignition in the Grewer Oven for the pure test item an exothermic multi-stage process was detected from above 190 °C, which led to a maximum temperature of approx. 600 °C (200 °C above the corresponding temperature of the reference material). A black residue remained in the wire basket after the test.

Conclusions:

The pure test item indicated self-ignition at atmospheric pressure starting at a temperature of 190 °C.

Executive summary:

The self-heating behaviour of the test material was determined in the Grewer Oven according to VDI guideline 2263, part 1 and with respect to the classification procedure of the UN Transport Regulation (Class 4, Division 4.2) and GHS or Regulation (EC) No 1272/2008 (CLP Regulation) Annex I: 2.11), respectively.The pure test item Proteinpulver indicated self-ignition at atmospheric pressure starting at a temperature of 190 °C.

Description of key information

The pure test item indicated self-ignition at atmospheric pressure starting at a temperature of 190 °C.

Key value for chemical safety assessment

Autoflammability / Self-ignition temperature at 101 325 Pa:

190 °C