Registration Dossier

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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

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Disodium peroxide (Na2O2) in contact with water, being quasi-instantaneously degraded according to the reaction:

Na2O2 + H20 -> 2NaOH + 1/2O2

 

According to annex XI.2 and OECD guidance document on aquatic toxicity testing of difficult substances and mixtures (OECD 2000), if the substance is likely to be unstable, a decision to test the parent substance and/or its degradation products, if identified, should be based on a consideration of its half-life under test and real-world conditions.

The following decision criteria are suggested in the OECD guidance (OECD, 2000) document only as a guide for static and semi-static tests with medium renewal times of 24 hours:

  • Half-life > 3 days: test parent substance;
  • Half-life < 3 days and >1 hour: consider on a case-by-case basis, and include possible testing of degradation products;
  • Half life < 1 hour: test degradation products

Testing of both parent compound and/ or degradation products will depend on the physico-chemical properties of the substance, the objectives and regulatory requirement.

In the present case, considering the high reactivity with water of the parent substance (half life of Na2O2 < 1 hour), the disodium peroxide can be considered as a hydrolytically unstable substance justifying a non-testing decision for the evaluation of it toxicity to aquatic organisms.

 

Hence, the toxicity of the substance needs to be estimated by taking into account the indirect toxicity of its degradation products, which is beyond the scope of this report.

 

The environmental risk assessment is to be performed using the toxicity data of disodium peroxide degradation product (NaOH) which is considered in its relative registration dossier. Considering the nature of the degradation product, sufficient data related to ecotoxicological properties are generated for this substance (European RAR available). The results of the chemical safety assessment clearly indicate that there is no need to investigate further the effects of the substance and/or the relevant degradation products.

Additional information