Triethylamine

Toxicity to aquatic algae and cyanobacteria

Description of key information

Pseudokirchneriella subcapitata, OECD Guideline 201: ErC50(72h): 8.0 mg/L, NOECr(72h): 1.1 mg/L; based on AUC: EC50(72h): 6.8 mg/L, NOEC(72h): 1.8 mg/L (Ministry of the Environment in Japan, 1999) 
RA approach (tripropylamine, CAS 102-69-2), Desmodesmus subspicatus, DIN 38423 L9: EC50(96h): 24.82 mg/L (growth rate), EC50(96h): 15.14 mg/L (biomass) (BASF AG, 1989) 
Effect concentration: 1 mg/L (Bringmann and Kuhn, 1959). 

Key value for chemical safety assessment

EC50 for freshwater algae:

8 mg/L

EC10 or NOEC for freshwater algae:

1.1 mg/L

Additional information

The Ministry of the Environment in Japan (1999d) conducted an ecotoxicity experiment to investigate the acute toxicity towards the freshwater algae Pseudokirchneriella subcapitata. The experimental conditions were in accordance with OECD Guideline 201. Based on the growth rate, the ErC50(72h) was determined as 8.0 mg/L while the NOEC(72h) amounts to 1.1 mg/L. Based on the Area Under the Curve (AUC), the EC50(72h) is reported as 6.8 mg/L while the NOEC(72h) amounts to 1.8 mg/L.

As supporting information, a read-across approach is intended to tripropylamine (CAS 102-69-2) which is based on the structural analogy to the test substance triethylamine (CAS 121-44-8). The toxicity of tripropylamine towards Desmodesmus subspicatus was investigated according to German industrial standard test guideline DIN 38423, part L9 (BASF AG, 1989). No GLP compliance is reported. Following a preliminary range-finding test, the test organisms were exposed to nominal concentrations of the test substance of 0, 5, 10, 25, 50, 100 and 250 mg/L as well as 250 mg/L neutralised test solution. The test duration was 96 hours at a temperature of 21.8 °C. EC50 values based on growth rate as well as on biomass were reported as 24.82 mg/L and 15.14 mg/L, respectively. The toxic effects of the substance are probably due to an increase in pH at high concentrations of the test substance. The read-across is based upon the structural analogy of both chemicals.

Another supporting study was performed by Bringmann and Kuhn (1959). Scenedesmus quadricauda was exposed to triethylamine in a static freshwater test for 96 hours. As basis of effects, the cell number population and the abundance in the population were taken into consideration. As final result, an effect concentration of 1 mg/L is reported which is based on cell number population. Further specifications of the effective concentration are not provided in the publication.