Perhydroimidazo[4,5-d]imidazole-2,5-dione

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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:

08-02-2018 to 09-02-2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Performed under GLP, all relevant validity criteria were met.

Reason / purpose for cross-reference:

assessment report

Qualifier:

according to guideline

Guideline:

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

Principles of method if other than guideline:

Apparatus :
Oven: 2 litre temperature programmed oven with natural air circulation.
Wire mesh cube: 20 mm cube constructed of stainless steel wire mesh with 0.045 mm openings.
Thermocouples: 2 calibrated K type thermocouples.

Principle of the Test:
The test item is heated in a fine mesh stainless steel cube that is suspended in an oven. The temperature/time-curves of both test item and oven were recorded.

Performance of the Test:
The test is conducted in accordance with the procedure described in EU Regulation (EC) 440/2008, Annex Part A test A.16.

GLP compliance:

yes

Specific details on test material used for the study:

Batch number: PHI/051217.
Appearance: Observed to be a light brown solid.

Key result

Remarks on result:

no self-ignition observed up to the melting point

Remarks:

/No relative self-ignition below its melting temperature (272.0°C) was observed. The substance on completion of the study at atmospheric pressure of 1013.0hPa.

The test item was observed to be a light brown solid. Whilst heating the sample, one exothermic event was recorded with an onset temperture of 300°C and a peak temperature at 324.27°C.

Conclusions:

The relative self-ignition temperature of the substance was determined using a relevant test method (EU Method A.16). No relative self-ignition temperature below its melting temperature was observed (at up to 272.0°C).

Executive summary:

The relative self-ignition temperature for solids was examined using EU Method A.16 under GLP for the test item. This involved the test item being heated in a fine mesh stainless steel cube that is suspended in an oven with a thermocouple placed within the sample and another within the oven. The oven temperature was programmed to increase from ambient to 400°C at a rate of 0.5 °C/min. The temperature/time curves relating to the condition in the centre of the sample and the oven were recorded. The test item was observed to be a light brown solid.

Whilst heating the sample, one exothermic event was recorded with an onset temperture of 300°C and a peak temperature at 324.27°C.

The test item was determined not to have a relative self-ignition temperature below its melting temperature.

Description of key information

Relative self-ignition temperature for solids: no relative self-ignition below the melting temperature (272 °C) was observed.

Additional information

The relative self-ignition temperature for solids was examined using EU Method A.16 under GLP for the test item. This involved the test item being heated in a fine mesh stainless steel cube that is suspended in an oven with a thermocouple placed within the sample and another within the oven. The oven temperature was programmed to increase from ambient to 400°C at a rate of 0.5C/min. The temperature/time curves relating to the condition in the centre of the sample and the oven were recorded. The test item was a light brown solid. The sample had one exothermic event with an onset temperature of 300°C and a peak temperature of 324.27°C. The sample did not reach 400°C by self-heating.

Applicant assessment indicates that: the classification of self-heating substances and mixtures does not apply and that further testing in a method consistent with the UN Test N.4 test method for self-heating substances is not scientifically necessary. The EU Method A.16 test served as a suitable screening test for self-ignition properties and in accordance with REACH Regulation (EC) No. 1907/2006: Annex VII section 7.12 the test item clearly had a melting point <272.0 °C and was entirely molten above 300 °C. Substances which are entirely molten < 160 °C should not be considered for classification in this class since the melting process is endothermic and the substance-airsurface is drastically reduced.

 

Therefore there is sufficient evidence to conclude on classification and labelling and to preclude further testing according to UN Transport of Dangerous Goods Manual of Tests and Criteria: Test N.4.

 

References:

1. UN Transport of Dangerous Goods Manual of Tests and Criteria, Sixth Edition (2015)

3. ECHA Guidance on Information Requirements and Chemical Safety Assessment (Chapter R.7a: Endpoint Specific Guidance, R.7.1.12, July 2017).

4. REACH Regulation (EC) 1907/2006, Annex XI, section 1

5. CLP Regulation (EC) 1272/2008, Annex I, section 2.11

6. ECHA Guidance on Application on the CLP Criteria, section 2.11 (v5.0, July 2017)