N,N''-(4-methyl-m-phenylene)bis[N',N'-dimethylurea]

Auto flammability

Link to relevant study record(s)

Reference

Endpoint:

self-ignition of dust accumulation

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2003-01-14

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

no guideline followed

Principles of method if other than guideline:

Dispersed dust: This test determines the ignition temperature of flammable dispersed dusty substances on hot surfaces. See section "any other information on materials and methods" for detailed description of the method.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (as cited in study report): TDI Uron
- Substance type: organic
- Physical state: solid

Key result

Self-ignition temperature:

>= 435 °C

The lowest temperature at which ignition of dispersed TDI-Urone dust was observed was 435°C.

Conclusions:

The lowest temperature at which ignition of dispersed TDI-Urone dust was observed was 435°C.

Executive summary:

The test determines the ignition temperature of a dispersed dusty test substance on hot surfaces. The test is conducted according to a test protocol. The surface area of the substance is increased intentionally in this test by preparing the test substance accordingly to simulate the dispersed dusty properties. The ignition temperature of dispersed dusty test material is expected to be significantly lower than the ignition temperature of the solid with larger particle diameters. The lowest temperature at which ignition of dispersed TDI-Urone dust was observed was 435°C.

Description of key information

Two tests for dusty TDI-Urone are available evaluating the auto-flammability on hot surface for deposited and dispersed

TDI-Urone with particle diameter of 0.25 mm. No auto-ignition of deposited TDI-Urone dust occurred on surfaces until 360°C.
The lowest temperature at which ignition of dispersed TDI-Urone dust was observed was 435°C.

Additional information

The test for deposited TDI-Urone (100 mg) was conducted for 5 min on a hot surface up to 360°C. No reaction was observed.

The test for dispersed TDI-Urone was conducted on a surface up to 600°C. The lowest temperature at which ignition of dispersed TDI-Urone dust was observed was 435°C.

As the tests were conducted with smaller particle diameters due to grinding and sieving the tested dusty TDI-Urone is expected to react even more sensible with regard to auto-flammability as original TDI-Urone produced directly from the operating facilities. Therefore it is concluded that the self-ignition temperature of TDI-Urone is higher than 360°C. This temperature is higher than the melting point (approx. 185°C). Thus TDI-Urone melts before it is self-ignited.