C12-18-(even numbered, C18 unsaturated)-alkylamines acetates

Short-term toxicity to fish

Description of key information

The available data reveal an increasing toxicity with raising chain length. The only exception is stearylamine where only a summary test report is available which indicates a slight drop of toxicity.

The lowest, well documented 96h-LC50 reported for fish is 0.11 mg/L (nominal) for oleylamine. In this study the short-term toxicity to Pimephales promelas was examined by Akzo Nobel (1995) in the presence and absence of humic acid using a static water test system according to the OECD Guideline 203 (1984). Fish were exposed at about 21°C for 96 h in reconstituted freshwater (pH 7.7-8.3, oxygen content 9.0-8.3 mg/l). Since the test material was insoluble in water, stock dispersions (approx. 0.1 g/L) were freshly prepared by ultrasonic treatment before each test was started. During each dosing step, the stock solutions were stirred to prevent any inhomogeneity of the stock solutions. At the start of the tests, all test solutions were clear and homogeneous. Five test concentrations in the nominal concentration range between 0.05 and 0.49 mg/L were employed. As test substance Oleyl alkyl amine with a purity of 94% was used. During all tests the test substance content decreased strongly showing a rather wide spread of the recovery rates. The test protocol explained this by the following factors:

-         Adsorption onto the walls of test vessels or – especially - on other surfaces (such like the surfaces of the test animals).

-         Reaction with organic materials (humic acid).

-         Humic acid might act as an emulsifier and hence is likely to influence the extraction process during the chemical analysis (HPLC).

-         An incomplete water removal during the analytical procedure causes disturbances of the chemical analysis.

However, based on nominal concentrations a 96 h-LC50 of 0.11 mg/L was derived from this study. When taking the results of the chemical analysis into account by using the mean recovery rate (about 51%) as the actual test concentration throughout the test, the 96 h-LC50 can be calculated as 0.06 mg/L.

From this study it can also be concluded that humic acid clearly has an effect on bioavailability of oleylamine for fish. As compared to the test results without humic acid, the addition of 10 mg/L humic acid resulted in an approximate 14-fold decrease the calculated LC50 based on nominal concentrations and about 20-fold based on analytically determined concentrations.

Acute fish tests were also conducted in natural river water (River Boehme) with a DOC of 6.3 mg/L and suspended matter of 16.7 mg/L (Noack, 2006). The lowest 96h-LC50bulk of 0.84mg/L was derived for cocoamine. In river water the Primary alkyl amines which are cationic surfactants at pH relevant in the environment, are either dissolved in water or sorbed to dissolved and particulate matter. No or negligible sorption to glass ware occurs under these conditions which was confirmed by measurements. This ensures reliable as well as reproducible results. The ecotoxicity is mitigated due to sorption but this kind of tests at least ensures that all added test substance is present in the test system and available for the exposure of the organism in dissolved or sorbed form. Mitigation can be taken into account by a factor of 10 applied to the ecotoxicity result (L(E)C₅₀) for C&L. For risk assessment purposes these ecotoxicity results can be compared with the total or bulk concentration in surface water.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.84 mg/L