Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Potassium thiocyanate has been subject to a recent review as a biocide, where Netherlands was the rapporteur member state. (DAR, KSCN, February 2008). In general most of the studies used in this report have also been used for this registration. A comparison of aquatic toxicity data for ammonium and potassium containing substances showed that for invertebrates, the toxicity of ammonium is similar to or higher than that of potassium, and is higher for fish. Therefore toxicity data of NH4SCN are found to be suitable as an indication of toxicity of KSCN, if no data on KSCN are available. In those cases the endpoint as determined on the basis of NH4SCN is recalculated into the equivalent KSCN concentration using the relative molar mass. Since the phys-chem properties of KSCN are mostly similar to those of NaSCN, data for these compounds can be used interchangeably.

Summary of key studies for aquatic toxicity (values in bold indicate the compound which was tested)

Endpoint Key study   SCN- NH4SCN KSCN NaSCN
  Reference Organism mg/L mg/L mg/L mg/L
             
Short term toxicity to fish (96 h LC50) Bogers, M. (1999) Oncorhynchus mykiss 49,60 65,00 82,98 69,23
Long term toxicity to fish (124 d NOEC Lanno, R.P. and Dixon, D.G. (1994) Pimephales promelas 1,10 1,31 1,84 1,53
Short term toxicity to aquatic invertebrates (48 h EC50) van Wijk, R.J. and Garttener-Arends, I.C.M. (1999) Daphnia magna 2,72 3,56 4,54 3,79
Long term toxicity to aquatic invertebrates (21 d NOEC) Thomas, P., van der Togt, B., and Kluskens, B. (2005) Daphnia magna 0,95 1,25 1,60 1,33
Toxicity to aquatic algae and cyanobacteria (72 h NOEC) van Wijk, R.J. and Garttener-Arends, I. (1999b) P. subcapitata 81,26 106,50 135,97 113,43
Toxicity to microorganisms Garttener-Arends, I.C.M and van Ginkel. (1999)  activated sludge 1,52 2 2,55 2,13

Where one compound has been tested, read across has been performed to the other analogues, by recalculation based on molecular weight.