C16-18-(even numbered)-alkyl fatty acid, compound with C16-18-(even numbered)-alkylamine

Endpoint summary

Description of key information

The registered substance is a salt composed of a primary alkyl amine and a fatty acid (stearic acid). Terrestrial toxicity data are available for equivalent chain length fatty amine and it is appropriate to use these data by a read-across approach for the registered substance. Indeed, the presence of stearate has no effect on the fate of the salt in the environment and thus the sorption to soil is expected to be similar between the registered substances and the primary alkyl amines.

Short-term and long-term toxicity data on earthworms, and toxicity to terrestrial plants are available for hydrogenated and non-hydrogenated tallow alkyl amine.

Toxicity to soil macro organisms

Acute toxicity

Noack (1999) determined the acute effects of tallow alkyl amine (CAS 61790 -33 -8) on earthworm Eisenia fetidaaccording to OECD Guideline 207. Different concentrations of test substance (100, 180, 320, 580, 1000 mg/kg dry weight) were applied once at the beginning of the test. No significant mortality was observed in any of the tested concentrations after 14 days of exposure. As test result a LC50 > 1000 mg/kg dry weight was obtained from this study.

Long-term toxicity

The effects of amines, hydrogenated tallow (CAS 61788 -45 -2) on mortality, biomass and reproduction of Eisenia fetida were tested according to OECD 222 under a static exposure for56 days (Noack, 2006). Natural soil (Lufa 2.2) was used as substrate, and the different concentration of the substance mixed with the substrate. The concentrations applied were 50, 100, 200, 500, and 1,000 mg/kg soil dry weight. In addition tests using control and vehicle control were performed.

The test is valid without restrictions and the results are reliable. After 28 days of exposure, no effects on survival of the adult worms were observed in all concentrations. After the following four weeks, the reproduction rate (average number of juveniles) was significantly reduced in the concentrations of 500 and 1,000 mg/kg soil compared to the control. Hence, the LOEC is 500 mg/kg soil and the NOEC 200 mg/kg soil.This NOEC can be used as a chronic endpoint representing heterotrophs (consumer) in the terrestrial environment.

Toxicity to terrestrial plants

Two acute studies have been performed on terrestrial organisms (plants and earthworms) using both tallow alkyl amine (CAS 61790 -33 -8) as test substance:

The growth test with terrestrial plants was conducted according to the OECD Guideline 208 by Noack (2000). Test systems were a monocotyledon (oat) and two dicotyledons (red clover and radish). Seeds of each plant were exposed to different concentrations of tallow alkyl amine (1, 10, 100 mg test item per kg soil dry weight) and a control. No vehicles were used to dissolve the test substance. The toxic effects of the soil incorporated test item on the emergence of seedlings and the early stages of growth were determined by visual observations and dry weight determination. No phytotoxic effects were observed throughout the test in all replicates resulting in a LC50 (emergence) and a EC50 (growth) of > 100 mg/kg dw.As no effect on growth and emergence for all three species was observed at the highest concentration of 100 mg/kg dw. the NOEC is > 100 mg/kg dw. as well. The NOEC can be used as a chronic endpoint representing autotrophs (producer) in the terrestrial compartment.