Yttrium zirconium oxide

Flammability

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

flammable solids

Data waiving:

other justification

Justification for data waiving:

other:

Reference 2

Endpoint:

substances / mixtures which in contact with water emit flammable gases

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the experience in production or handling shows that the substance does not react with water, e.g. the substance is manufactured with water or washed with water

Reference 3

Endpoint:

pyrophoric solids

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is known to be stable in contact with air at room temperature for prolonged periods of time (days) and hence, the classification procedure does not need to be applied

Reference 4

Endpoint:

self-heating substances / mixtures

Data waiving:

other justification

Justification for data waiving:

other:

Reference 5

Endpoint:

flammability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2005-10-17 to 2005-11-08

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Well conducted study, however no proper assessment can be made due to major deficiencies in comparison with today's accepted standards and the lacking information on substance identity.

Qualifier:

no guideline followed

Principles of method if other than guideline:

3 cm³ of sample was put on an inorganic heat insulating plate. A test flame of 70 mm was applied to the sample in an area of 1-2 cm² and at an angle of approx. 30°. After 10 seconds the test flame was taken away from the sample. A stopwatch was used to measure the time required to ignite the sample from the application of the test flame. Observation was made if combustion continued or not. The test was repeated 10 times.

GLP compliance:

not specified

Following criteria were applied to determine the flammability of the sample:

very ignitable:       ignition time =< 3 seconds

ignitable:              3 seconds < ignition time <= 10 seconds

non-hazardous:     No combustion or Not measurable

For all 10 replicates no ignition occurred within 10 seconds, the sample was therefore considered to be non-hazardous

Conclusions:

The test sample was considered non-hazardous under the study conditions as it did not ignite in contact with a flame.

Description of key information

Based on the chemical structure of yttrium zirconium oxide and experience in daily use it can be concluded that yttrium zirconium oxide is non flammable. This is supported by a supporting Klimisch 3 study by Akari (2005).

Key value for chemical safety assessment

Flammability:

not classified

Additional information

Testing on yttrium zirconium oxide is considered not to be required as based on the chemical structure and experience with daily use and handling it can be concluded that yttrium zirconium oxide is non flammable. The study from Akari (2005) confirms the non-flammability, however, this study was considered not entirely reliable because - although well performed - there were too much deviations from today's accepted standards.

Justification for classification or non-classification

Pyrophoricity

In the daily use and handling of yttrium zirconium oxide during which continuous exposure to air can occur, no spontaneous ignition is observed. The absence of structural alerts furthermore confirms that it is highly unlikely that yttrium zirconium oxide has pyrophoric properties.

Flammability in contact with water

Under conditions where yttrium zirconium oxide is in contact with water no ignition and/or liberation of flammable gases is observed. The absence of structural alerts furthermore confirms that it is highly unlikely that yttrium zirconium oxide is flammable in contact with water.

Flammability

Inorganic oxides in which the inorganic element 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 yttrium and zirconium in yttrium zirconium oxide is in its highest possible state (4+ for zirconium and 3+ for yttrium) and thus yttrium zirconium oxide can be considered as non-flammable.

Self-heating

The oxidation state of zirconium and yttrium in yttrium zirconium oxide is in its highest possible state (4+ for zirconium and 3+ for yttrium) and thus yttrium zirconium oxide can be considered as non-flammable and not sensitive to self-heating.