A mixture of: 3,5-dimethylthio-2,4-toluenediamine; 3,5-dimethylthio-2,6-toluenediamine

Short-term toxicity to fish

Description of key information

The test item was found to be toxic to Rainbow trout showing the following results:
- EC50: 16.9 mg/l based on nominal concentrations / 7.3 mg/l based on mean measured concentrations
- NOEC: 10 mg/l based on nominal concentrations

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

7.3 mg/L

Additional information

The toxicity to fish was determined in a GLP study under semi-static conditions over a test period of 96 hours, in accordance with EU-method C.1 and OECD guideline 203.

Measured test article concentrations at the start of the test ranged from 4.03 to 9.08 mg/l, despite the nominal concentrations ranging up to 1000 mg/l. Concentrations increased over the 96 hour test period, but were greatly less than nominal concentrations. Test dilutions showed undissolved test article, and became discolored over time. This indicated that the test article was tested above it's water solubility. The acute lethal toxicity of rainbow trout was assessed under static conditions over 96 hrs. In a definitive test, groups of 10 fish were exposed to 5 nominal concentrations between 10 and 100 mg/l. The fish were observed 0.25, 2 and 4 hrs after the start of the test and then at least every 24 hrs for the remainder of the study. No fish died at the lowest concentration. The lowest nominal exposure concentration which caused 100% mortality after 96 hrs. was 32 mg/l. Based on measured concentrations the 96-h LC50 was 7.3 mg/l

The test item was found to be toxic to Rainbow trout showing the following results:

- EC50: 16.9 mg/l based on nominal concentrations / 7.3 mg/l based on mean measured concentrations

- NOEC: 10 mg/l based on nominal concentrations