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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

In accordance with REACH Annex XI, section 2, testing is technically not feasible as a consequence of the properties of the substance:

  • And In vitro tests on the mutagenic potential of disodium oxide in bacteria are considered dispensable for principal considerations, since inorganic metal compounds are frequently negative in this assay due to limited capacity for uptake of metal ions (guidance on Information Requirements and Chemical Safety Assessment - Chapter R.7a: Endpoint Specific Guidance), an Ames study is not relevant for metal (guide 7a, p565).
  • Disodium oxide, in contact of humidity, gives Sodium Hydroxide. The modification of the pH, due the sodium hydroxide, are known to lead to artefactual, positive results which do not reflect intrinsic mutagenicity of the test substance. Therefore, positive results from these references should be considered with extreme care, and require a very thorough case-by-case validation.

 And there are sufficient data on the breakdown product (sodium hydroxide n°CAS 1310 -73 -2) which was investigated (European RAR and REACH registration). Thereover, the breakdown substances are exempted to Registration following Annex V (Entry I).

Link to relevant study records

Referenceopen allclose all

Endpoint:
in vitro cytogenicity / micronucleus study
Data waiving:
study technically not feasible
Justification for data waiving:
other:
Justification for type of information:
JUSTIFICATION FOR DATA WAIVING
In accordance with REACH Annex XI, section 2, testing (OECD 487) is technically not feasible as a consequence of the properties of the substance (hydrolytically unstable substance and quasi-instantaneously degraded in contact with moist skin or mucuous membranes). See Attached justification for more details.
Endpoint:
in vitro gene mutation study in mammalian cells
Data waiving:
study technically not feasible
Justification for data waiving:
other:
Justification for type of information:
JUSTIFICATION FOR DATA WAIVING
In accordance with REACH Annex XI, section 2, testing (OECD 476) is technically not feasible as a consequence of the properties of the substance (hydrolytically unstable substance and quasi-instantaneously degraded in contact with moist skin or mucuous membranes). See Attached justification for more details.
Endpoint:
in vitro gene mutation study in bacteria
Data waiving:
study technically not feasible
Justification for data waiving:
other:
Justification for type of information:
JUSTIFICATION FOR DATA WAIVING
Testing is technically not feasible as a consequence of the properties of the substance (hydrolytically unstable substance and quasi-instantaneously degraded in contact with moist skin/ mucuous membranes). See Attached justification for more details.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Additional information

Justification for classification or non-classification

Disodium oxide quasi-instantaneously degraded in contact with moist skin or mucuous membranes to form Sodium Hydroxide. Testing disodium oxide for genetic toxicity is for this reason not relevant at all, but breakdown products have to be considered (classification for sodium hydroxide has been elaborated in the frame of REACH and sodium hydroxide is not genotoxic). For these reasons, no classification could be set for genetic toxicity.