Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Short-term toxicity to fish:

96-h-LC50: 89.1 mg/l nominal (100 % a.i)

 

Short-term toxicity to aquatic invertebrates:

48h-EC50: 42.4 mg/l (nominal, 100 % a.i.).

 

Toxicity to aquatic algae and cyanobacteria: 

EC50: 130 mg/l (nominal). 

  

Toxicity to microorganisms: 

EC50: 1380 mg/L (nominal)

10d-EC10: 200 mg/L (nominal)

Additional information

Short-term toxicity to fish:

The acute toxicity of Guanidine thiocyanate was tested in a 96-h toxicity test in Poecilia reticulate (Guppy). The 96-h-LC50 was 89.1 mg/l nominal (100 % a.i)

 

Short-term toxicity to aquatic invertebrates:

The 48h-acute toxicity of Guanidine thiocyanate to aquatic invertebrates (Daphnids) was studied. A 48h-EC50 based on immobilization was found to be 42.4 mg/l (nominal, 100 % a.i.).

 

Toxicity to aquatic algae and cyanobacteria: 

In a 72 hour acute toxicity study, the cultures of Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) were exposed to Guanidine Thiocyanate under static conditions. 

EC50values based on measurement of in vivo chlorophyll fluorescence was 130 mg/l (nominal). 

  

Toxicity to microorganisms: 

The acute toxicity to bacteria of Guanidine Thiocyanate was tested in a Bacterial Luminescence Assay (LUMIStox (Dr. Lange GmbH, Dusseldorf, Germany)).Cultures of Photobacterium phosphoreum were exposed to 5 different concentrations for 30 min. The EC50 was determined to be 1380 mg/L (nominal) by bioluminescence measurement.

 

The biodegradability of Guanidinium Thiocyanate exposed to activated sludge of a municipal sewage treatment plant was investigated under aerobic static conditions according to OECD guideline 302B. The test substance reached a biodegradation of 46 % after 28 days and is thus inherently biodegradable. As the test substance is proven to be inherently biodegradable, according toTGDs, Chapter R.10,the respective test concentration can be used to derive a NOEC.

According to the degradation curve, the inocculum was active until the end of test (28d). As most of degradation occured until day10 (42% degradation), 10d-EC10, as a worst case assumption, was estimated to  be 200mg/L.