Dilithium tetraborate

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:

14 September 2017 – 04 January 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: UN Manual of Tests and Criteria: Test N.4 (Test method for self-heating substances)

Deviations:

no

Principles of method if other than guideline:

As stated in the ECHA guidance, Guidance on Information Requirements and Chemical Safety Assessment Chapter R.7a, the UN Test N.4 is preferable for solids to generate information for this endpoint.

GLP compliance:

yes (incl. QA statement)

Key result

Remarks on result:

other: Negative outcome (no effect observed)

A substance is classified as a self-heating substance of UN Class 4, Division 4.2 if a positive test result is observed in a 100 mm basket at 140°C. A positive result is defined as a sample temperature rise of 60°C (or more) above the oven temperature during a 24 hour period.

No changes to the sample temperature were observed during the testing over a 24 hour period. The results can therefore exclude the test item as a self-heating solid and is therefore not subject to transportation restrictions of UN Class 4 Division 4.2.

Table 1: Detailed UN 4.2 Test Results

Basket Number	Basket Size (mm cube)	Test temperature (°C)	Test System	Sample Weight (g)	Ignition
1	100	140	9	685.8	N

Conclusions:

No changes to the sample temperature were observed during the testing over a 24 hour period. The results can therefore exclude the test item as a self-heating solid and is therefore not subject to transportation restrictions of UN Class 4 Division 4.2.

Executive summary:

For solids, self-heating may occur by reaction with air with subsequent ignition. According to the CLP Regulation, Annex I, section 2.11, a self heating substance or mixture is a liquid or solid substance or mixture, other than a pyrophoric liquid or solid, which, by reaction with air and without energy supply, is liable to self-heat. Therefore the self ignition temperature of solids are considered under self heating and as a result, the UN Test N.4 is preferable for solids to generate information for this endpoint

For a substance to be classified as a self-heating substance of UN Class 4, Division 4.2 then a positive test result needs to observed in a 100 mm basket at 140°C. A positive result is defined as a sample temperature rise of 60°C (or more) above the oven temperature during a 24 hour period. No changes to the sample temperature were observed during the testing over a 24 hour period. The results can therefore exclude the test item as a self-heating solid and is therefore not subject to transportation restrictions of UN Class 4 Division 4.2.

Description of key information

As stated in the ECHA guidance, Guidance on Information Requirements and Chemical Safety Assessment Chapter R.7a,  the UN Test N.4 is preferable for solids to generate information for this endpoint.

No changes to the sample temperature were observed during the testing over a 24 hour period. The results can therefore exclude the test item as a self-heating solid and is therefore not subject to transportation restrictions of UN Class 4 Division 4.2.