2,4-di-tert-butylphenol

Toxicity to aquatic algae and cyanobacteria

Description of key information

ErC50 (72 h) = 0.37 mg/l (OECD 201)
NOErC (72 h)  = 0.073 mg/l

Key value for chemical safety assessment

EC50 for freshwater algae:

0.37 mg/L

EC10 or NOEC for freshwater algae:

0.073 mg/L

Additional information

ErC₅₀ (72h) for the growth rate was determined to be 9.85 mg/L, and for the yield, EyC50 (72h) to be 3.61 mg/l. The growth rate NOErC (72h) was calculated to be 2.2 mg/L; LOErC (72h) was 4.0 mg/L. The yield NOEyC (72h) was 1.2 mg/L; LOEyC (72h) was 2.2 mg/L.

Concentrations analysed were between 2.5 and 4.0% of the nominal concentrations (corresponding to the theoretical concentration of the saturated solution of 33 mg/L). Measured exposure concentrations decreased to 31.9 - 39.1% of the initial concentrations during the course of the test. The geometric mean of the exposure concentrations analysed were between 0.48 and 0.030 mg/L. ErC50(72h, conc, analysed) was determined to be 0.37 mg/l, EyC50 (72h, concentration analysed) was 0.13 mg/l. NOErC (72h concentration analysed) was 0.073 mg/l and NOE_yC (72h concentration analysed) was 0.030 mg/l.