fatty acid chloride, C12, reaction product with sodium glutamate and sodium hydroxide

Endpoint summary

Description of key information

Summary of the aquatic toxicity endpoints derived with the test item or via read-across (RA) to analogue substance

Test type	Guideline	Species	Effect	Value (mg/L)
Acute fish	OECD 249	Oncorhynchus mykiss gill cells	EC50 (24h)	211.38
Acute daphnia	OECD 202	Daphnia magna	EC50 (48h)	32.9
Algae	OECD 201	Pseudokirchneriella subcapitata	ErC50 (72h)	>100
Bacteria (RA)	OECD 209	Municipal sludge	EC50 (3h)	791
Chronic daphnia (RA)	OECD 211	Daphnia magna	NOEC (21d) Reprod	4
Algae	OECD 201	Pseudokirchneriella subcapitata	ErC10 (72h)	51.2

 

Short-term toxicity to fish

An alternative study according to OECD 249 with rainbow trout gill cells with the test item fatty acid chloride, C12, reaction product with sodium glutamate and sodium hydroxide has been performed.
EC50 (24h) = 211.38 mg/L (nominal) for Oncorhynchus mykiss gill cells (OECD 249).

The weight of evidence approach with argumentation lines 1-4 provide evidence and justifies the use of an alternative test system (RTgill-W1 assay) for the acute fish test following the 3R principles. Predictions, comparisons with structurally similar susbtances and experiments have clearly shown that fish are the least sensitive to the test item compared to other trophic levels. This allows, on the basis of scientifically based results in the sense of animal welfare and 3R principle, to avoid killing fish for an acute fish test and to use instead a recognized OECD guideline 249 for an in vitro test with RTgill-W1 cells.

 

Short-term toxicity to invertebrate

 

Based on the nominal concentrations of the test item, the 48 hours-EC50 for Daphnia magna was 36.0 mg/L (confidence limits: 32.4 – 40.2 mg/L) for the test item fatty acid chloride, C12, reaction product with sodium glutamate and sodium hydroxide.
Based on the geometric mean measured concentrations, the 48 hours-EC50 for Daphnia magna was 32.9 mg/L (confidence limits: 29.4 – 36.9 mg/L) for the test item.

 

Toxicity to aquatic algae

 

In this study, fatty acid chloride, C12, reaction product with sodium glutamate and sodium hydroxide was found to inhibit the growth of the freshwater green alga Pseudokirchneriella subcapitata after 72 hours with the following effect values (based on nominal test item concentrations):
The EC50-values for inhibition of growth rate (ErC50) and yield (EyC50) after 72 hours were > 100 mg/L and 80.7 (61.2 – > 100) mg/L, respectively. The ErC10 (72h) value for inhibition of growth rate was 51.2 mg/L. NOEC-values for inhibition of growth rate and yield after 72 hours were 10.0 and 1.00 mg/L, respectively.

 

Toxicity to microorganisms

 

No studies investigating the toxicity of fatty acid chloride, C12, reaction product with sodium glutamate and sodium hydroxide to microorganisms are available. Thus, available data for the source substance Sodium N-cocoyl glycinate was used in a read across approach. The read across is considered valid as both substances are structurally similar, which assume very similar physico-chemical properties resulting in identical environmental behaviour and ecotoxicity.

A Respiration Inhibition Test with activated sludge according to OECD Guideline No. 209 was carried out with the test item Sodium N-cocoyl-glycinate. Test system was activated sludge of the municipal treatment plant of D-31137 Hildesheim. The test was carried out under static conditions with the nominal active ingredient concentrations 100 - 180 - 320 - 580 - 1000 mg/L. The respiration rates of the control, reference and test item replicates were measured after a contact time of three hours, and the inhibitory effects of the test and reference item were determined in comparison to the control respiration rates. The mean inhibition of respiration for the test item replicates ranged from -33 % to 62 %.

The NOEC of the active ingredient is 320 mg/L, the EC10 is 372 mg/L and the EC50 791 mg/L to activated sludge of a municipal sewage treatment plant.

 

Long Term Toxicity to invertebrate

 

No long-term test with the test item fatty acid chloride, C12, reaction product with sodium glutamate and sodium hydroxide is available. No long-term test on invertebrates is required for Annex VIII. However, since invertebrates are the most sensitive species to the test item, this inclusion appears useful for evaluation and risk assessment. Therefore, the data of the anaolgue substance Sodium N-cocoyl glycinate were used. 

The Lowest Observed Effect Concentration (LOEC) and the No Observed Effect Concentration (NOEC) for the reproductive output were determined directly from reduction of the reproductive output. EC10- and EC50- values for the reproductive output and the adult mortality could not be estimated because effects > 10 % were not observed.

As the concentrations in the old media (48 h) were below LOQ, the endpoints were assessed based on the nominal test item concentrations corrected with a factor of 2. Endpoint assessment based on mean measured concentrations is not possible, because the toxicity cannot be attributed to any single compound of the test item Hostapon SG containing different C-chains of the N-Cocoyl glycine sodium salt. Therefore, it was concluded that an evaluation on half of the nominal concentrations sufficiently describes a worst case scenario. Additionally the endpoints are given based on half of nominal concentrations of the active ingredient (a.i.) taking its content of 19.8 % into account.

 

NOECReproduction       :       20 mg/L, corresponding to    3.96 mg a.i./L

LOECReproduction       :    > 20 mg/L, corresponding to > 3.96 mg a.i./L

 

NOECAdult Mortality       :       20 mg/L, corresponding to    3.96 mg a.i./L

LOECAdult Mortality       :    > 20 mg/L, corresponding to > 3.96 mg a.i./L