Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Ecotoxicological information

Short-term toxicity to fish

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Not acute toxic, no indication for classification

Key value for chemical safety assessment

Fresh water fish

Fresh water fish
Effect concentration:
1 000 mg/L

Additional information

The short-term toxicity of Guanidine carbonate (CAS 593-85-1) to fish was investigated in a GLP-compliant study (Fenzl 1998) using zebra fish (Danio rerio) according to the EU C.1 (2008) protocol. The experiment is deemed valid, conclusive and thus suitable for assessment without restrictions. The test organisms were exposed during 96 h to 0 or 100 mg/L. The analytical dose verification revealed > 99 % in the daily sampled probes. Thus the effects were related to nominal concentrations. No mortalities occurred during the test and no differences between treatment and control were observed. Accordingly the 96 h L(E)C0 = 96 h L(C)0 was ≥ 100 mg/L and in consequence the L(E)C50 was found significantly > 100 mg/L. In conclusion the test item was not acute toxic to fish and on the basis of this study no indication for classification is given.

This result is supported by another experimental LC50. Adema (1988) determined the 48 h LC50 of Guanidinium chloride (CAS 50-01-1) to orfe (Leuciscus idus) to be 1758 mg/L, which corresponds to 1658 mg/L of the submission item Guanidine carbonate. Read-across and conversion on the basis of equimolar Guanidinium kation formation seems justified regarding the dissociation behaviour in the environmentally relevant pH range of 4-9 (see discussion of dissociation constant) and the assumed comparable toxicological irrelevance of the chloride and the hydrogen carbonate/carbonate species. Careful extrapolation considering the reduced exposure time suggests the actual LC 50 of Guanidine carbonate in the order of 1000 mg/L.

In summary the acute toxicity of the submission item to fish is irrelevantly low and seem to range more than 10 times above the acute aquatic toxicity cut-off limit of 100 mg/L.

It is thus concluded that Guanidine carbonate is not acute toxic to fish and on the basis of data from the trophic level of secondary consumers in the aquatic environments no classification requirements are indicated.

  • Adema DMM (1988). The acute toxicity of Guanidine hydrochloride to Leuciscus idus L. TNO Division of Technology for Society. Report no.: R88/241. Report date: 1988-06-22. [European Chemicals Bureau; IUCLID Dataset, Guanidine chloride (CAS # 50-01-1) p 8 (2000 CD-ROM edition). Available from, as of March 4, 2008:]