Zirconium dichloride oxide

Flammability

Link to relevant study record(s)

Reference

Reference 1

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

other:

Reference 2

Endpoint:

flammable solids

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

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:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Description of key information

When zirconium dichloride oxide is heated it decomposes. This decomposition becomes significant at approximately 60°C and results in the formation of zirconium dioxide under the release of water and hydrochloric acid. Decomposition is an endothermic reaction making the substance not liable to burning. Furthermore, 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 zirconium in zirconium dichloride oxide as well as in zirconium dioxide is in its highest possible state (4+) and thus zirconium dichloride oxide can be considered as non-flammable.

Key value for chemical safety assessment

Flammability:

not classified

Additional information

Pyrophoricity

In the daily use and handling of zirconium dichloride 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 zirconium dichloride oxide has pyrophoric properties.

Flammability in contact with water

Under conditions where zirconium dichloride 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 zirconium dichloride oxide is flammable in contact with water.

Flammability

When zirconium dichloride oxide is heated it decomposes. This decomposition becomes significant at approximately 60°C and results in the formation of zirconium dioxide under the release of water and hydrochloric acid. Decomposition is an endothermic reaction making the substance not liable to burning. Furthermore, 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 zirconium in zirconium dichloride oxide as well as in zirconium dioxide is in its highest possible state (4+) and thus zirconium dichloride oxide can be considered as non-flammable.

Self-heating

Although zirconium dichloride oxide decomposes before melting, the endothermic reaction from the decomposition which starts around 60°C indicates that this substance can be considered not to be sensitive to self-ignition. The decomposition product zirconium dioxide is also concluded not to be sensitive to self-ignition (data taken from the IUCLID data base on zirconium dioxide). Therefore, the substance is not considered to be self-heating.

Justification for classification or non-classification

Zirconium dichloride oxide is not considered to be flammable, pyrophoric, self-heating, nor a substance which emits flammable gases in contact with water based on waiver statements (see above).