reaction mass of cerium(IV)oxide, praseodymium(III,IV)oxide and zirconium (IV)oxide

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:

weight of evidence

Study period:

17 July 2012 - 21 January 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks on result:

other: The test material has been determined not to have a self-ignition temperature below 400 °C.

The test material was a brown powder. Whilst heating, the sample showed no significant temperature rise above the oven temperature. On completion of the test, the cube remained full of a brown powder.

Conclusions:

The test material has been determined not to have a self-ignition temperature below 400 °C.

Executive summary:

The relative self-ignition temperature of the test material was investigated in accordance with the standardised guideline EU Method A.16.

A wire mesh cube was completely filled with the test material and placed in the centre of an oven at room temperature. A thermocouple was placed in the centre of the sample and another in the oven. The oven temperature was increased from ambient to 400 °C at a rate of 0.5 °C/min.

Whilst heating, the test material showed no significant temperature rise above the oven temperature.

The test material has been determined not to have a self-ignition temperature below 400 °C.

Reference 2

Endpoint:

relative self-ignition temperature (solids)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

10 June 2005 - 13 October 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

Cited as Directive 92/69/EEC, A.16

Deviations:

yes

Remarks:

The maximum oven temperature was 300°C instead of 400°C as required by the guideline. A Grewer test was done in addition, in order to confirm the results up to 500°C.

GLP compliance:

yes

Relative self-ignition temperature:

> 400 °C

Pressure not indicated.

Conclusions:

Cerium dioxide has no self-ignition temperature up to at least 400°C.

Executive summary:

The determination of the relative self-ignition temperature of cerium dioxide was performed according to EU Method A16 only up to 300°C with a plateau. No self-ignition was observed up to 300°C. A Grewer test, performed up to 500°C, was done as a complement to the previous test.
No exothermic reaction was observed up to 500°C. The test item has no self-ignition temperature up to at least 400°C.

Reference 3

Endpoint:

relative self-ignition temperature (solids)

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

Since no reliable studies on this endpoint are available for the reaction mass of cerium dioxide, praseodymium(III,IV) oxide and zirconium dioxide, read across was performed using studies performed with praseodymium(III,IV) oxide and cerium dioxide. No such study is available for zirconium dioxide, however, as explained below, zirconium dioxide can be concluded to be not autoflammable based on non-testing information. The read across justification document is attached to IUCLID Section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Remarks on result:

other: The reaction mass of cerium dioxide, praseodymium(III,IV) oxide and zirconium dioxide is not expected to exhibit self-ignition properties.

Remarks:

This conclusion is based on testing information for cerium dioxide and praseodymium(III,IV) oxide and non-testing information for zirconium dioxide.

Conclusions:

Cerium dioxide and praseodymium(III,IV) oxide have been demonstrated not to be autoflammable up to a temperature of 400°C. No testing information is available for zirconium dioxide, however, inorganic oxides in which the element bound to oxygen is in its highest possible oxidation state are incapable of further reaction with oxygen and can thus be designated as non-flammable. The oxidation state of zirconium in zirconium dioxide is in its highest possible state (4+) and thus zirconium dioxide can be considered as non-flammable and will not be sensitive to self-ignition either. Based on this information on its main constituents, the reaction mass of cerium dioxide, praseodymium(III,IV) oxide and zirconium dioxide can be considered not to be sensitive to self-ignition either.

Description of key information

No key information is available on the auto-flammability and/or self-ignition temperature of the reaction mass of cerium dioxide, praseodymium(III,IV) oxide and zirconium dioxide. Cerium dioxide and praseodymium(III,IV) oxide have been demonstrated not to be autoflammable up to a temperature of 400°C (White, 2013, Klimisch 1; Cerutti, 2005, Klimisch 1). No testing information is available for zirconium dioxide, however, inorganic oxides in which the element bound to oxygen is in its highest possible oxidation state are incapable of further reaction with oxygen and can thus be designated as non-flammable. The oxidation state of zirconium in zirconium dioxide is in its highest possible state (4+) and thus zirconium dioxide can be considered as non-flammable and will not be sensitive to self-ignition either. Based on this information on its main constituents, the reaction mass of cerium dioxide, praseodymium(III,IV) oxide and zirconium dioxide can be considered not to be sensitive to self-ignition either.

Additional information

1. Information on cerium dioxide

Based on a guideline study (Cerutti, 2005; Klimisch 1) it can be concluded that cerium dioxide has no auto-ignition temperature up to at least 400°C.

2. Information on praseodymium(III,IV) oxide

Based on a guideline study (White, 2013; Klimisch 1) it can be concluded that praseodymium(III,IV) oxide has no auto-ignition temperature up to at least 400°C.

3. Information on zirconium dioxide

Given that zirconium dioxide is an inorganic oxide in which zirconium is in its highest possible oxidation state (4+), it can be concluded to be incapable of further reaction with oxygen and can thus be designated as non-flammable and will not be sensitive to self-ignition.

4. Conclusion on the reaction mass of cerium dioxide, praseodymium(III,IV) oxide and zirconium dioxide

Based on the results for the three substances forming this reaction mass it can be safely concluded that the reaction mass does not exhibit auto-flammability or self-heating properties.