Cerium gadolinium oxide

Oxidising properties

Link to relevant study record(s)

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 (R^2)	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 (R^2)	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 (R^2)	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.