Aniline

Long-term toxicity to aquatic invertebrates

Description of key information

Daphnia magna: NOEC (21d) = 0.016 mg/L (Hutton 1989)
Daphnia magna: NOEC (21d) = 0.004 mg/L (Kuehn et al. 1988 1989)
Daphnia magna: NOEC (21d) = 0.024 mg/L (Gersich and Milazzo 1988)

Additional information

Hutton (1989) examined the effects of long-term exposure of Daphnia magna to aniline. The daphnids were exposed in a flow-through system at about 20°C. As dilution water hardened unfiltered fish tank water was used. During the test the daphnids were fed with trout chow and yeast daily. Five test concentrations; a DMF control and a water control were used. Nominal test concentrations were between 11 μg/l and 105 μg/l. However, weekly HPLC analysis of the test samples showed that the measured test concentration in all samples was about 50% of the nominal concentration. A 21-day NOEC related to reproduction of 16 μg/l (based on measured concentrations) was derived. The decreasing aniline concentration that was found in this flow-through study is attributed by the author to the presence of daphnid food.

 

In a semi-static test (three renewals per week) Kühn et al. (1988,1989) studied the long-term toxicity of aniline to Daphnia magna. The study was conducted at 25°C. During the test the daphnids were fed on fish food and activated sludge. Eight test concentrations ranging nominally from 0.1 μg/l to 316 μg/l were employed. A 21-day NOEC for reproduction of 10 μg/l based on nominal concentration was found. As it was not possible to analyse the real aniline concentrationlin the samples (detection limit of the used method was 0.1 mg/l an additional test vessel without daphnids and food but with a nominal aniline concentration of 316 μg/l was employed. After 2 days the aniline concentration in this sample was only 40 to 60% of the nominal concentration. Therefore, a NOEC value of 4 μg/l is extrapolated from this recovery rate. This extrapolation does not take into account the possibly enhanced degradation of aniline in the presence of daphnid food.

 

Gersich and Milazzo (1988) examined the effect of aniline to Daphnia magna in a long-term study. The daphnids were exposed under semi-static conditions at 20°C for 21 days. During the tests the daphnids were fed on green algae. Aniline concentrations ranging nominally from 10.6 μg/l to 170 μg/l were employed. The stability of aniline over the renewal period was examined by analyzing particular test solutions at 0-hour and 48-hour. A mean deviation of about 82% was found. A NOEC of 24 μg/l for reproduction based on mean analysed concentrations was reported.