Calcium oxide

Storage stability and reactivity towards container material

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

storage stability and reactivity towards container material

Type of information:

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

Adequacy of study:

supporting study

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

This study was performed by a governmental agency (the German "Bundesanstalt für Materialforschung und -prüfung, BAM; Federal Institute for Material Research and Testing) with respect to classification according to transport regulations. However, documentation of the testing procedure is relatively brief. Therefore, in view of the general reliability of governmental institutes, the report was considered to be reliable with restrictions. Since calcium oxide reacts to calcium hydroxide in contact with water the results of this study can be considered relevant also for calcium oxide.

Qualifier:

no guideline available

Principles of method if other than guideline:

According to IMDG-Code S.8003, if the corrosion rate at 55 °C test temperature is lower than 6.25 mm/year, the test material is non-corrosive to metal surfaces.

GLP compliance:

no

Type of method:

testing for reactivity towards container material

Remarks:

Testing of the corrosivity of milk of lime (turbid aqueous solution of calcium dihydroxide) towards steel and aluminium (potential container materials).

Specific details on test material used for the study:

PACKAGING
- Type of container / packaging: Aluminium sheets were used as surrogate for a container
- Pack size: Not applicable
- Approximate empty weigth or volume: Not applicable

TEST CONDITIONS
- Study duration: 60 days
- Temperature: 55 °C
- Humidity: No data, sheets were immersed half or completely
- Sampling times: End of study

ANALYTICAL METHODS
- Analytical method used: None
- Handling of test samples prior to sampling: Not applicable

OTHER
- The corrosion rate was determined in mm/year according IMDG-Code S.8003.
- The oxide layer of the aluminium sheet was removed prior to exposure.

Results:

40 % milk of lime: Corrosion rate: < 6.25 mm/year (at 55 °C)
10 % milk of lime: Corrosion rate: < 6.25 mm/year (at 55 °C)

Transformation products:

not specified

Storage stability / reactivity towards container material:

corrosive to container material

Conclusions:

According to the criteria of IMDG-Code S.8003, milk of lime (40 % or 10 % aqueous solution of calcium dihydroxide) is not corrosive to aluminium (and steel).

Reference 2

Endpoint:

storage stability and reactivity towards container material

Type of information:

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

Adequacy of study:

supporting study

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

This study was performed by a governmental agency (the German "Bundesanstalt für Materialforschung und -prüfung, BAM; Federal Institute for Material Research and Testing) with respect to classification according to transport regulations. However, documentation of the testing procedure is relatively brief. Therefore, in view of the general reliability of governmental institutes, the report was considered to be reliable with restrictions. Since calcium oxide reacts to calcium hydroxide in contact with water the results of this study can be considered relevant also for calcium oxide.

Qualifier:

no guideline available

Principles of method if other than guideline:

According to IMDG-Code S.8003, if the corrosion rate at 55 °C test temperature is lower than 6.25 mm/year, the test material is non-corrosive to metal surfaces.

GLP compliance:

no

Type of method:

testing for reactivity towards container material

Remarks:

Testing of the corrosivity of milk of lime (turbid aqueous solution of calcium dihydroxide) towards steel and aluminium (potential container materials).

Specific details on test material used for the study:

PACKAGING
- Type of container / packaging: Steel sheet was used as surrogate for a container
- Pack size: Not applicable
- Approximate empty weigth or volume: Not applicable

TEST CONDITIONS
- Study duration: 60 days
- Temperature: 55 °C
- Humidity: No data, sheets were immersed half or completely
- Sampling times: End of study

ANALYTICAL METHODS
- Analytical method used: None
- Handling of test samples prior to sampling: Not applicable

OTHER
- The corrosion rate was determined in mm/year according IMDG-Code S.8003.
- The oxide layer of the aluminium sheet was removed prior to exposure.

Results:

40 % milk of lime: Corrosion rate: < 6.25 mm/year (at 55 °C)
10 % milk of lime: Corrosion rate: < 6.25 mm/year (at 55 °C)

Transformation products:

not specified

Storage stability / reactivity towards container material:

corrosive to container material

Conclusions:

According to the criteria of IMDG-Code S.8003, milk of lime (40 % or 10 % aqueous solution of calcium dihydroxide) is not corrosive to steel (and aluminium).

Description of key information

The corrosion rate of aluminium and steel at 55 °C test temperature by aqueous solutions of calcium hydroxide is lower than 6.25 mm/year, thus the test material is non-corrosive to metal surfaces. This result is read-across to calcium oxide.

Additional information

Non-corrosive to metal surfaces. Since calcium oxide reacts to calcium hydroxide in contact with water the results of this study can be considered relevant also for calcium oxide.In addition, according to long years of experience manufacturing and handling the substance calcium carbonate, it is not considered corrosive to carbon steel and aluminium. Thus it may be concluded that all grades of calcium oxide will be non-corrosive to metal surfaces, irrespective of their calcium carbonate content.