N-(3-aminopropyl)-N- (C12-18 even numbered) alkyl-propane-1,3-diamine

Long-term toxicity to aquatic invertebrates

Description of key information

One long-term toxicity test with daphnia has been performed with Triamine C12-18, C18-unsaturated. The 21 d NOEC for reproduction is 270 μg a.i./L and the EC10 for parental mortality is 235 μg a.i./L. The effects are expressed as nominal values because the test was performed with river water as it is intended to be used in an evaluation of the environmental risks based on the Bulk approach. The parental EC50 (21d) was 342 μg a.i./L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

270 µg/L

Additional information

In the long term daphnia study no reduction of the reproductive output, but hormesis was observed. The statistically significant increase of 28 % of the reproductive output in comparison to the control at the concentration level 270 µg/L was the most sensitive effect in this study. The EC10-value for the reproductive output was calculated by sigmoidal dose-response regression based on the nominal test item concentrations. An EC50-value for the reproductive output was not determinable because no effects ≥ 50 % (reduction or increase of the reproductive output) occurred within the tested concentration range. The NOEC was assessed as adverse effect level directly from the observation data taking the observed hormesis not into account. All effect values are given based on the nominal concentrations. Effect values EC10, Reproduction: 63.7 µg/L (reproduction increase) EC50, Reproduction: Not determinable Adverse effect value NOEC Reproduction: 270 µg/L. The recoveries in the fresh media were in the range of 81 to 108 % of the nominal values. In the old media (after 48 h or 72 h) recoveries in the range of < LOQ to 88 % were determined. Biodegradation as possible reason for the observed decrease of the test concentration during the exposure period is very unlikely considering the short time frame between the refreshments of the test solutions. The concentration of the test item adsorbed to the glassware as determined exemplarily at the test concentration level of 270 µg/L was 64.8 µg/L which corresponds to 24 % of the nominal concentration. The observed concentration decrease between fresh and old media is thus only for a small fraction caused by sorption to the glassware. The main reduction is therefore most likely caused by thermodynamically more favourable redistribution of the sorbed fraction resulting in an additional sorption to suspended matter and DOC. Because of the limited sorption to glassware and unlikeliness of biodegradation as possible reason for the reduction of the observed concentration it must be concluded that the test organisms were fully exposed to the bulk concentration of the test substance during the test. All effect values given are therefore based on the nominal test item concentrations.