Iridium

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant, guideline study, available as unpublished report, acceptable without restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

other: EC No 1272/2008 using modified N.4 (Self Heating Substances) of the United Nations Recommendations on the Transport of Danergous Goods, Manual of Tests and Criteria, fifth revised edition 2009

Deviations:

yes

Remarks:

the test item was only available in very limited amounts and was extremely expensive. Therefore, in order to obtain as much information as possible on the self heating properties of the test item a modified procedure was employed

Principles of method if other than guideline:

An aliquot of the test item was suspended in a stainless steel mesh cube (approximately 25 x 25 x 25 mm) in an oven. A thermocouple was placed in the centre of the sample and another in the oven. The oven was heated to 140°C and held at this temperature for a period of 24 hours. The temperature of the oven and the sample were continuously monitored over the 24 hour period. After this period the oven temperature was increased from 140 to 400°C at a rate of 30°C/hour. The temperature of the oven and the sample were continuously monitored throughout.

GLP compliance:

yes (incl. QA statement)

Relative self-ignition temperature:

> 400 °C

Remarks on result:

other: Standard pressure assumed. There were no signs of self-ignition or self-heating over the duration of the test.

Remarks:

at atm. press. of 101.3 kPa

Conclusions:

Iridium (solid only) showed no signs of self-ignition or self-heating over the duration of the test.

Executive summary:

This is a GLP compliant, guideline study considered suitable for use as the key study for this endpoint. Iridium (solid only) showed no signs of self-ignition or self heating over the duration of the test.

Reference 2

Endpoint:

relative self-ignition temperature (solids)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant, guideline study, available as unpublished report, acceptable without restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

other: EC No 1272/2008 using modified N.4 (Self Heating Substances) of the United Nations Recommendations on the Transport of Danergous Goods, Manual of Tests and Criteria, fifth revised edition 2009

Deviations:

yes

Remarks:

the test item was only available in very limited amounts and was extremely expensive. Therefore, in order to obtain as much information as possible on the self heating properties of the test item a modified procedure was employed

Principles of method if other than guideline:

An aliquot of the test item was suspended in a stainless steel mesh cube (approximately 25 x 25 x 25 mm) in an oven. A thermocouple was placed in the centre of the sample and another in the oven. The oven was heated to 140°C and held at this temperature for a period of 24 hours. The temperature of the oven and the sample were continuously monitored over the 24 hour period. After this period the oven temperature was increased from 140 to 400°C at a rate of 30°C/hour. The temperature of the oven and the sample were continuously monitored throughout. Failure of the chart recorder at a sample temperature of 365°C led to no data being collected above that temperature. However, it was considered that the data collected, i.e. up to a sample temperature of 365°C, was sufficient for the basic requirements of the (modified) test.

GLP compliance:

yes (incl. QA statement)

Relative self-ignition temperature:

> 365 °C

Remarks on result:

other: Standard pressure assumed. Iridium (black) showed no signs of self-ignition or self-heating when held at 140°C for 24 hours. When heated from 140 to 365°C, the sample temperature did not exceed the oven temperature by >60°C.

Remarks:

at atm. press. of 101.3 kPa

Conclusions:

Iridium (black) showed no signs of self-ignition or self-heating when the test item was held at 140°C for 24 hours. Additionally, when the test item was heated from 140 to 365°C, the sample temperature did not exceed the oven temperature by great than 60°C

Executive summary:

This is a GLP compliant, guideline study considered suitable for use as the key study for this endpoint. Iridium (black) showed no signs of self-ignition or self-heating when the test item was held at 140°C for 24 hours. Additionally, when the test item was heated from 140 to 365°C, the sample temperature did not exceed the oven temperature by great than 60°C.

Description of key information

No signs of self-ignition or self-heating over the duration of the test were observed for iridium or iridium black.

Additional information

Iridium showed no signs of self-ignition or self-heating over the duration of the test (Harlan 2011a). Iridium (black) showed no signs of self-ignition or self-heating when the test item was held at 140°C for 24 hours (Harlan 2011b). Additionally, when the test item was heated from 140 to 365°C, the sample temperature did not exceed the oven temperature by greater than 60°C. Both studies follow a modified N4 guideline, adapted to use a smaller amount of sample, and are GLP-compliant. They are considered suitable for use as the key studies for this endpoint.