1,1-dimethylurea

Auto flammability

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

relative self-ignition temperature (solids)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

September 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

not specified

Specific details on test material used for the study:

- Analytical purity: 99.9 %
- Lot/batch No.: 301601

Key result

Remarks on result:

no self-ignition observed up to the melting point

The test phenomena and results of the test are shown in the following table:

No.	1	2
Sample volume	8cm^3	8cm^3
Heating rate	0.5^oC/min	0.5^oC/min
Oven Temperature when Sample Temperature reached its melting point/range	About 2^oC higher thanSample Temperature	About 2^oC higher thanSample Temperature
Test phenomena	1) The sample temperature could not reach 400^oCuntil the sample was heated to its melting point. 2) There was no substance in the vessel after the test completed.	1) The sample temperature could not reach 400^oCuntil the sample was heated to its melting point. 2) There was no substance in the vessel after the test completed.

1) It could be considered as an endothermic effect from the sample melting that the oven temperature was about 2 °C higher than the sample temperature when the sample was heated to its melting point.

2) There was no substance in the vessel after the test was completed. This could prove that the sample in the vessel had melted and flowed away from the cribriform vessel.

3) The sample temperature could not reach 400 °C prior to that of the oven until the sample was heated to its melting point. It could be confirmed that the relative self-ignition temperature was above the melting point.

Conclusions:

The sample temperature could not reach 400 °C prior to that of the oven, until the sample was heated to its melting point. Therefore the relative self-ignition temperature of 1,1 -Dimethylurea lies above its melting point.

Executive summary:

The relative self-ignition temperature of 1,1 -Dimethylurea was determined in a test sccording to EC Regulation No.440/2008 Annex A.16. A certain volume of the sample was placed in an oven and was heated at a constant but low rate. The temperature of the oven and in the centre of the sample were continuously recorded at the same time. For the purpose of this test, the tamperature of the oven at which the sample temperature reached 400 °C prior to the oven by self-heating was called the relative self-ignition temperature.

The sample temoperature could not reach 400 °C prior to that of the oven, until the sample was heated to its melting point. Therefore the relative self-ignition temperature of 1,1 -Dimethylurea lies above its melting point.

Reference 2

Endpoint:

self-ignition of dust accumulation

Remarks:

deposited dust

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

February 2004

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

DIN EN 15188 (Determination of the spontaneous ignition behaviour of dust accumulations)

Principles of method if other than guideline:

This test determines the ignition temperature of a dry product on a hot surface. For a description of the method see "any other information on materials and methods".

GLP compliance:

not specified

Key result

Self-ignition temperature:

> 360 °C

At the highest temperature (360 °C) no ignition, but the test substance 1,1-Dimethylurea starts to smoke when put onto the hot surface.

Conclusions:

No auto-ignition of deposited 1,1-Dimethylurea dust occured on surfaces until 360 °C.

Executive summary:

The test determines the ignition temperature of a deposited dusty test substance on hot surfaces. The test is conducted according to the test protocol. The surface area of the substance is increased intentionally in this test by preparing the test substance accordingly to simulate the deposited dusty properties. The ignition temperature of deposited dusty test material is expected to be lower than the ignition temperature of the solid with larger particle diameters. At the hottest temperature in this test (360°C) no auto-ignition of deposited 1,1-Dimethylurea dust occured.

Reference 3

Endpoint:

self-ignition of dust accumulation

Remarks:

dispersed dust

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

February - March 2004

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

DIN EN 15188 (Determination of the spontaneous ignition behaviour of dust accumulations)

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

Key result

Self-ignition temperature:

425 °C

Weighted sample	Temperature	Reaction
100 mg	455 °C	ignition
100 mg	450 °C	ignition
100 mg	442 °C	ignition
100 mg	435 °C	no ignition
100 mg	430 °C	no ignition
300 mg	448 °C	ignition
300 mg	445 °C	ignition
300 mg	437 °C	no ignition
300 mg	432 °C	no ignition
300 mg	426 °C	no ignition
500 mg	423 °C	no ignition
500 mg	426 °C	ignition
500 mg	420 °C	no ignition
500 mg	414 °C	no ignition
500 mg	408 °C	no ignition

Conclusions:

The autoflammabilty temperature of dispersed dust of 1,1-Dimethylurea was tested to be 425 °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 autoflammabilty temperature of dispersed dust of 1,1 -Dimethylurea was tested to be 425 °C.

Description of key information

No auto-ignition of deposited dust of 1,1 -Dimethylurea occurred on hot surfaces until 360°C.

The autoflammability temperature of dispersed dust of 1,1 -Dimethylurea was tested to be 425 °C.

Furthermore the relative self-ignition temperature of 1,1 -Dimethylurea was determined in a test according to EC Regulation No.440/2008 Annex A.16. The test indicates that the relative self-ignition temperature of 1,1 -Dimethylurea lies above its melting point.

Key value for chemical safety assessment

Autoflammability / Self-ignition temperature at 101 325 Pa:

425 °C