Tris(oxiranylmethyl) benzene-1,2,4-tricarboxylate

Toxicity to microorganisms

Description of key information

Toxicity of tris(oxiranylmethyl) benzene-1,2,4-tricarboxylate to Activated Sludge in a Respiration Inhibition Test

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

28.9 mg/L

Additional information

In comparison to the inoculum controls the respiration rate of the activated sludge was slightly inhibited by 8.1% at the lowest nominal test concentration of 10 mg/L. At the next higher concentrations of nominal 32 and 100 mg/L the inhibition was 10.8%. The respiration rate of the activated sludge was moderately inhibited by 27.0% at 320 mg/L. At a nominal concentration of 1000 mg/L, the respiration rate was inhibited by 29.7% at a plateau. Concentrations exceeding 1000 mg/L nominal were not tested.

Based on measured inhibition rates, the 3-hour EC₁₀, and EC₂₀and their 95% confidence limits were determined. Based on measured inhibition rates, the 3-hour EC₅₀could not be quantified because up to the highest nominal test concentration of 1000 mg/L less than 30% inhibition was noted after three hours incubation

The results are listed below:

      Parameter         EC₁₀           EC₂₀           EC₅₀

   Value [mg/L]           28.9           211.4             n.d.

   lower 95%-cl             0.0            33.6             n.d.

   upper 95%-cl         100.2           742.8             n.d.

n.d.: not determined due to mathematical reasons