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

Long-term toxicity to aquatic invertebrates

Description of key information

The chronic toxicity of coco alkyl amine, tallow alkyl amine and oleylamine to Daphnia magna was studied under comparable conditions by Noack (2002) using a semi-static test system according to the OECD Guideline 211 (Sept. 1998). Five test concentrations in the nominal concentration range between 0.013 and 0.5 mg/L were applied by diluting a stock dispersion (10 mg/l). Test solutions were renewed three times per week. As dilution water natural river water of agricultural background (middle reach of the river “Böhme”, lower Saxony) was used. This river has been chosen due to its properties representing typical conditions of a German medium sized river. The concentration of suspended matter measured in the river water was in a range of 11.2 to 32.8 mg/L (mean value 18.4 mg/L) for coco alkyl amine and tallow alkyl amine and in a range of 10.0 to 26.2 mg/L (mean value 17.4 mg/L) for oleylamine. The content of humic acid amounted to 11.8 mg/L in all tests. A pre-treatment of the test vessels was not performed.

The concentrations of the active ingredient were determined in the old and new test media once per week in the stock solution, the highest test concentration of 0.5 mg/L and the control via GC-analysis. All samples were taken and analyzed without filtration to include test item adsorbed on suspended matter. In all tests the test item concentration decreased at the end of the test and recovery rates varied strongly (see Table). According to the test protocol the most probable reason for the decrease or incomplete recovery during the test was seen in adsorption on particulate matter and humic acids. The variation in the recovery rates were explained by small differences in the concentration of suspended matter. The results were therefore based on nominal concentrations representing the total exposure concentration (dissolved and adsorbed on humic acid / suspended matter).

Table Daphnia magna repro test with natural river water- analytically verified concentrations of the highest test item concentration (0.5 mg/L) [mg/l]

	Coco alkyl amine			Tallow alkyl amine			Oleylamine
Sample No.	new media (0 hours)	old media (3 days)	recovery	new media (0 hours)	old media (3 days)	recovery	new media (0 hours)	old media (3 days)	recovery
1	0.4	< LOQ	40%	0.2	< LOQ	20%	0.14	0.11	25%
2	0.2	< LOQ	20%	0.2	< LOQ	20%	0.22	< LOQ	22%
3	< LOQ	0.2	20%	0.3	0.2	50%	0.28	0.24	52%
4	< LOQ	< LOQ	0%	0.4	0.2	60%	0.24	0.23	47%
			mean 20%			mean 37.5%			mean 36.5%

           < LOQ   below limit of quantification

 

Referring to nominal concentrations a 21d-NOECrepro of 0.013 mg/L was derived for coco alkyl amine, tallow alkyl amine and oleylamine. When considering the validity of these studies, the following factors should be taken into account: 

-         No measures were taken to prevent the loss of test substance by adsorption onto surface of the test vessels. Therefore, a quantification of the fraction lost by adsorption onto the glass ware is not possible.

-         Only the highest test concentration was analytically verified showing highly variable recovery rates. At concentrations around the NOEC even lower recovery rates have to be expected. Due to this, the exposure concentrations maintained during the studies are highly uncertain.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.013 mg/L