Registration Dossier
Registration Dossier
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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.
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 233-340-5 | CAS number: 10124-53-5
Long-term toxicity to fish
Administrative data
Link to relevant study record(s)
Description of key information
A chronic nominal 34d-NOEC of ≥316 mg test substance for fish, i.e., ≥80.4 mg S/L is proposed for this endpoint. Translating this value to thiosulftate results in ≥140.6 mg S2032-/L.
Key value for chemical safety assessment
Fresh water fish
Fresh water fish
- Effect concentration:
- 140.6 mg/L
Additional information
- thiosulfates oxidize to sulfites (and subsequently to sulfate) under normal environmental conditions (e.g., through microbial activity);
- the acute toxicity of thiosulfates and sulfites/disulfites are both related to their impact on physicochemical parameters (decrease on the pH through formation of H2SO4, oxygen depletion due to oxidation of these reducing sulfur substances);
- acute fish toxicity data for sulfites/disulfites were lower than those that were identified for thiosulfates. The key acute value for sulfites was 149.6 mg SO32-/L, whereas the lowest value using a thiosultate as test substance was 831 mg/L as SO32-.Both data were generated for the same test species (Salmo gairdneri). Similar findings were observed for other trophic levels. It is therefore concluded that read-across from chronic sulfite toxicity data can be considered as a worst-case.
No reliable data on chronic toxicity of ammonium thiosulfate to fish were identified. Reliable chronic toxicity data, however, were reported in a GLP-OECD Guideline 210 early-life stage (ELS) study, using sodium sulfite (Na2SO3) as test substance. The following arguments are put forward that support a read-across approach of data generated with sulfites/disulfites:
In the ELS study with sodium sulfite, five different substance concentrations were evaluated, but no adverse effects on hatching , post–hatch mortality, health, length and dry weight of surviving fish were observed. Consequently, a chronic nominal 34d-NOEC of ≥316 mg test substance for fish, i.e., ≥80.4 mg S/L is proposed for this endpoint. Translating this value to thiosulftate results in ≥140.6 mg S2032-/L.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
