Disodium (Z)-4-(9-octadecenylamino)-4-oxo-2(or 3)-sulphonatobutyrate

Short-term toxicity to fish

Description of key information

96 h LC50 > 100 mg as/L

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

100 mg/L

Additional information

In the Klimisch 2 GLP study from Kimmel (2013) the acute toxicity of Butanoic acid, 4-amino-4-oxo-2(or 3)-sulfo-,N-(C16-C18 (even numbered), C18 unsaturated alkyl)), disodium salts to rainbow trout (Oncorrhynchus mykiss) was determined in a 96‑hour static test according to the EU Commission Directive 92/69/, Part C.1, the Commission Regulation (EC) No 440/2008, Part C.1 and the OECD Guideline for Testing of Chemicals No. 203 (1992).

A limit test was performed in accordance with the test guidelines to demonstrate that the test item (product) has no lethal effect on the test fish up to the highest concentration which could be dissolved in the test water. Thus, an undiluted filtrate of a saturated dispersion with the loading rate of 285 mg/L was tested as a single concentration of the test item (product). Additionally, a control was tested in parallel (test water without addition of the product).

A limit test was performed in accordance with the threshold approach requiring that the fish test be performed with a single concentration close to or slightly higher than the lowest EC50 value obtained in tests with algae and daphnia. The threshold approach (based on the Guidance on Information Requirements and Chemical Safety Assessment, ECHA (2008), and the OECD Series on Testing and Assessment No. 126, Short guidance on the threshold approach for acute toxicity (2010)) was used to demonstrate that rainbow trout is not the most sensitive species for this product. Due to the low water solubility of the test item (product) in the test medium, two dispersions with the loading rate of 285 mg/L were prepared at the start of the test by dispersing 2.2796 and 2.2798 g of the test item (product) in 8 L of test water, respectively. This preparation was supported by ultrasonic treatment for 15 minutes and intense stirring on a magnetic stirrer over 3 hours in the dark, to dissolve a maximum amount of the product in the dispersions. No auxiliary solvent or emulsifier was used. After the 3-hour stirring period, the dispersions of the test item (product) were filtered through a membrane filter (pore size 0.45 μm). The test medium was prepared just before introduction of the fish (= start of the exposure).

In the control and test medium with the loading rate of 285 mg test item (product) /L (100 mg solid content/L), all fish survived until the end of the test, but visible abnormalities (changed body color, fish mainly at the bottom of the test vessel, tumbling during swimming) were observed at some test fish from Day 1 to 4. Due to the lack of mortality the 96-hour LL50 was higher than the loading rate of 285 mg test item (product)/L (100 mg solid content/L).

As stated in the ECHA document "Guidance on the application of the CLP criteria, Guidance to Regulation (EC) No 1272/2008 of classification, labelling and packaging (CLP) of substances and mixtures, version 3.0 November 2012" page 493 Annex I.4.5 Complex substances "This loading level from the ... WAF may be used directly in the classification criteria."

The read across for this fish study is justified since the main constituents of unsaturated C₁₈alkyl rests are similar in both substances and the similarity of the ecotoxicological findings for the algae and daphnia studies for both substances. CAS 58353-68-7 (disodium (Z)-4-(9-octadecenylamino)-4-oxo-2(or 3)-sulphonatobutyrate) has a higher portion of unsaturated material and does not contain relevant parts of C₁₆and C18(unsaturated) alkyl groups which make up 20-40% and 10 -30% ofbutanoic acid, 4-amino-4-oxo-2(or 3)-sulfo-,N-(C₁₆-C₁₈(even numbered), C₁₈unsaturated alkyl)), disodium salts. Based on the almost identical physico-chemical parameters for both substances and the similar findings for the algae and daphnia studies this difference in the saturated/unsaturated C₁₈portion is considered to be of only minor relevance for the ecotoxicity. Hence, read across frombutanoic acid, 4 -amino-4 -oxo-2(or 3)-sulfo-,N-(C₁₆-C₁₈(even numbered), C₁₈unsaturated alkyl)),disodiumsalts to CAS 58353-68-7 is justified. Based on the data set and the supporting evidence for read across, no further risk assessment factor is needed.

Therefore, the LL50 of > 100 mg solid content/L is considered as relevant and reliable for the risk assessment.