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Reference
Endpoint:
oxidising solids
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 17 June 2021 to 29 September 2021
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Reason / purpose for cross-reference:
reference to same study
Remarks:
Other physico-chemical endpoints are covered in the study report of Demangel (2021).
Reason / purpose for cross-reference:
reference to same study
Remarks:
Other physico-chemical endpoints are covered in the study report of Demangel (2021).
Reason / purpose for cross-reference:
reference to same study
Remarks:
Other physico-chemical endpoints are covered in the study report of Demangel (2021).
Reason / purpose for cross-reference:
reference to same study
Remarks:
Other physico-chemical endpoints are covered in the study report of Demangel (2021).
Reason / purpose for cross-reference:
reference to same study
Remarks:
Other physico-chemical endpoints are covered in the study report of Demangel (2021).
Qualifier:
according to guideline
Guideline:
UN Manual of Tests and Criteria: Test O.3 (Gravimetric test for oxidizing solids)
Version / remarks:
Version: 2019
Deviations:
yes
Remarks:
Reference item purity was 78.5% CaO2 (75±1% described in the method). Test temperature was between 25.8 and 27.0°C (instead of 20±5 °C). These deviations were not considered to have affected the quality or the interpretation of the results obtained.
GLP compliance:
yes (incl. QA statement)
Remarks:
GLP certificate dated from 04 May 2021.
Contact with:
powdered cellulose
Key result
Sample tested:
4:1 sample-to-cellulose ratio
Parameter:
burning rate
Result:
0.046 g/s
Key result
Sample tested:
1:1 sample-to-cellulose ratio
Parameter:
burning rate
Result:
0.076 g/s
Key result
Sample tested:
reference: 1:2 mixture calcium peroxide + cellulose
Parameter:
burning rate
Result:
0.328 g/s

Mixture test item / cellulose – Ratio 4:1:


The mixture ignited, combustion was observed with smokes.






























































































Assay



1



2



3



4



5



Initial weight (g)



29.05



29.55



29.20



29.21



29.35



Final weight (g)



23.80



25.52



24.57



23.84



25.18



Weight difference (g)



5.25



4.03



4.63



5.37



4.17



Weight after 20% of the total mass loss



28.000



28.744



28.274



28.136



28.516



Weight after 80% of the total mass loss



24.850



26.326



25.496



24.914



26.014



Time corresponding to 20% of the reaction (s)



137.12



161.92



100.80



84.64



78.88



Time corresponding to 80% of the reaction (s)



217.44



248.80



180.00



163.20



146.40



Reaction time (s)



80.32



86.88



79.20



78.56



67.52



Burning rate (g/s)



0.045



0.041



0.045



0.046



0.053



Coefficient of correlation (R2)



0.9838



0.9450



0.9682



0.9738



0.9573



 


















Mean burning rate (g/s)



0.046



Standard deviation (SD, g/s)



0.004



Relative standard deviation (RSD, %)



9.4



 


Mixture test item / cellulose – Ratio 1:1:


The mixture ignited, combustion was observed with smokes.






























































































Assay



1



2



3



4



5



Initial weight (g)



29.17



29.29



29.51



29.62



29.86



Final weight (g)



18.05



17.54



15.70



19.74



15.95



Weight difference (g)



11.12



11.75



13.81



9.88



13.91



Weight after 20% of the total mass loss



26.946



26.940



26.748



27.644



27.078



Weight after 80% of the total mass loss



20.274



19.890



18.462



21.716



18.732



Time corresponding to 20% of the reaction (s)



142.72



121.76



76.48



104.32



131.68



Time corresponding to 80% of the reaction (s)



271.36



238.08



196.16



206.40



261.44



Reaction time (s)



128.64



116.32



119.68



102.08



129.76



Burning rate (g/s)



0.070



0.077



0.075



0.088



0.069



Coefficient of correlation (R2)



0.9890



0.9838



0.9833



0.9898



0.9442



 


















Mean burning rate (g/s)



0.076



Standard deviation (SD, g/s)



0.008



Relative standard deviation (RSD, %)



10.0



 


Mixture reference item / cellulose – Ratio 1:2:


The mixture ignited, combustion was observed with smokes.






























































































Assay



1



2



3



4



5



Initial weight (g)



29.18



29.39



29.55



29.83



29.29



Final weight (g)



11.81



11.59



11.37



15.27



13.57



Weight difference (g)



17.37



17.80



18.18



14.56



15.72



Weight after 20% of the total mass loss



25.706



25.830



25.914



26.918



26.146



Weight after 80% of the total mass loss



15.284



15.150



15.006



18.182



16.714



Time corresponding to 20% of the reaction (s)



64.80



54.72



61.12



73.44



66.24



Time corresponding to 80% of the reaction (s)



99.84



94.24



99.20



113.28



97.92



Reaction time (s)



35.04



39.52



38.08



39.84



31.68



Burning rate (g/s)



0.342



0.304



0.315



0.301



0.379



Coefficient of correlation (R2)



0.9858



0.9921



0.9834



0.9902



0.9809



 


















Mean burning rate (g/s)



0.328



Standard deviation (SD, g/s)



0.033



Relative standard deviation (RSD, %)



9.9



 


Conclusion:


The mean burning rate of reaction with the test item / cellulose mixture in proportion 4:1 (0.046 g/s) or 1:1 (0.076 g/s) was slower than the mean burning rate of reaction with the reference item / cellulose mixture in proportions 1:2 (0.328 g/s). Therefore, the test item was not considered to be an oxidizing solid.

Interpretation of results:
GHS criteria not met
Conclusions:
Cerium gadolinium oxide is not an oxidizing solid.
Executive summary:

The oxidizing properties of cerium gadolinium oxide were investigated in a GLP-compliant study according to UN O.3 method. The test item was mixed with dry fibrous cellulose in ratios of 1:1 and 4:1, by mass, of test item to cellulose. The burning rates of these mixtures were compared to the burning rate of the reference mixture of reference item (calcium peroxide) and cellulose in a ratio 1:2, by mass. The mass loss of the mixtures during combustion was determined using a balance connected to a software recording the data (loss of mass) as a function of time. The burning rate BR20-80 was calculated as the quotient of 60% of the total amount of cellulose in the conical pile and the main combustion time t20-80. The time t20-80 is the time between 20% and 80% of the total mass loss. The total mass loss is the difference in mass before ignition and at the end of the main reaction, defined as the time after which the mass loss rate is less than 1 g per minute. Five assays were conducted with each mixture and the mean burning rate was calculated. The mean burning rate of reaction with the test item / cellulose mixture in proportion 4:1 (0.046 g/s) or 1:1 (0.076 g/s) was slower than the mean burning rate of reaction with the reference item / cellulose mixture in proportions 1:2 (0.328 g/s). Therefore, it was concluded that cerium gadolinium oxide is not an oxidizing solid. 

Description of key information

Cerium gadolinium oxide has no oxidizing properties.

Key value for chemical safety assessment

Oxidising properties:
non oxidising

Additional information

An experimental study performed under GLP compliance and in accordance with UN O.3 method was flagged as a key study and assigned a Klimisch score of 1. It reports that cerium gadolinium oxide is not an oxidizing solid.

Justification for classification or non-classification

Based on the above described information, cerium gadolinium oxide does not need to be classified for its oxidizing properties under CLP.