Dipraseodymium dizirconium heptaoxide

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

Reference 2

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 3

Endpoint:

self-heating substances / mixtures

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Reference 4

Endpoint:

flammable solids

Type of information:

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

Adequacy of study:

weight of evidence

Justification for type of information:

Data available on the individual constituents of the substance were considered to conclude on the endpoint. For praseodymium(III,IV) oxide, an experimental study is available, which is used for read across. For zirconium dioxide no data are available on the endpoint, because there was no need for performing an experimental study (study waived, see further). The read across justification document is attached to IUCLID Section 13.

Reason / purpose for cross-reference:

read-across source

Specific details on test material used for the study:

Initially, this substance was considered as a reaction mass and named "reaction mass of praseodymium(III,IV) oxide and zirconium dioxide".
But after discussion with ECHA, it was stipulated that it is a substance and we had to change the name to "Dipraseodymium dizirconium heptaoxide".

So, in the different endpoints with studies, the sustance named "reaction mass of praseodymium(III,IV) oxide and zirconium dioxide" corresponds to the substance Dipraseodymium dizirconium heptaoxide. They are the same, the analytical dossier did not changed.

Test procedure:

other: based on read-across

Remarks on result:

other: The reaction mass of praseodymium(III,IV) oxide and zirconium dioxide is not considered to be flammable.

Remarks:

This conclusion is based on two types of information. First, the results of an experimental study performed with praseodymium(III,IV) oxide according to the UN N1 guideline demonstrated that praseodymium(III,IV) oxide is not flammable. Second, zirconium dioxide is concluded not to be flammable either, based on the fact that inorganic oxides in which the element is in its highest possible oxidation state are incapable of further reaction with oxygen, which is the case for zirconium dioxide (zirconium in oxidation state +IV). Consequently, the reaction mass of these two oxides can safely be concluded not to be flammable either.

Reference 5

Endpoint:

flammable 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

Qualifier:

according to guideline

Guideline:

UN Manual of Tests and Criteria: Test N.1 (Test method for readily combustible solids)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test procedure:

burning rate test: preliminary screening test

Burning time:

s

Remarks on result:

substance does not ignite and propagate combustion either by burning with flame or smouldering along 200 mm of the powder train within the 2 minutes test period

Preliminary Screening Test

The pile of test material failed to ignite during the 2 minutes that the Bunsen flame was applied.

Burning Rate Test

Due to the results obtained during the preliminary screening test, no definitive test was performed.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, the test material is not a flammable or readily combustible solid.

Description of key information

There is no experimental data available for dipraseodymium dizirconium heptaoxide on the endpoints of flammability, pyrophoricity, self-heating and flammability in contact with water. Based on information on its oxide constituents, the substance is not considered to be flammable nor pyrophoric nor flammable in contact with water, nor is it expected to exhibit self-heating properties.

Key value for chemical safety assessment

Flammability:

not classified

Additional information

1. Information on praseodymium(III,IV) oxide

Based on a guideline study (White, 2013; Klimisch 1), it is concluded that praseodymium(III,IV) oxide is not a flammable substance. In addition to this study, based on the physical and chemical properties of the substance and experience in its handling and use, praseodymium(III,IV) oxide is not expected to be pyrophoric or flammable in contact with water. Further, based on the observations made in the autoflammability test performed according to the EU A.16 guideline, the substance is also concluded not to have self-heating properties.

2. Information on zirconium dioxide

Zirconium dioxide is considered non-flammable since zirconium is in its highest possible oxidation state (+IV) and is therefore not capable of further reaction with oxygen. In addition, based on its physical and chemical properties and experience in its handling and use, it is concluded that zirconium dioxide is not pyrophoric or flammable in contact with water and does not have self-heating properties.

3. Conclusion on the substance dipraseodymium dizirconium heptaoxide

Based on above mentioned information on its individual oxide, the substance dipraseodymium dizirconium heptaoxide is not considered to be flammable nor pyrophoric nor flammable in contact with water, nor is it expected to exhibit self-heating properties.

Justification for classification or non-classification

Based on information available for its individual constituents, the substance dipraseodymium dizirconium heptaoxide is not considered to be flammable nor phyrophoric nor flammable in contact with water, nor is it expected to exhibit self-heating properties. The substance is not classified for any of these physical hazards.