N-(2-carboxyethyl)-N-octyl-β-alanine

Endpoint summary

Description of key information

Short-term toxicity to fish: An analogue test material gave LC50 (96 h) > 100 mg a.i./L based on mortality of Oncorhynchys mykiss (OECD 203).

 

Short-term toxicity to aquatic invertebrates: The registered substance gave EC50 (48 h) > 600 mg a.i./L based on immobilisation of Daphnia magna (OECD 202).

 

Long-term toxicity to aquatic invertebrates: The NOEC (21 d) reported for an analogue test item was > 24.06 mg a.i./L based on reproduction of Daphnia magna (OECD 211).

 

Algal growth: The registered substance gave EC50 (48 h) > 600 mg a.i./L based on growth rate of Chlorella vulgaris (OECD 201). An investigation involving an analogue substance reported a NOEC (72 h) value of > 46.2 mg a.i./L based on growth rate of Pseudokirchneriella subcapitata (OECD 201).

Microorganisms: Exposure of activated sludge to an analogue test item gave EC50 (3 h) > 246.4 mg a.i./L. No effect on microbial respiration was observed at the highest test concentration (OECD 209).

Additional information

Short-term toxicity to Fish

The acute toxicity of an analogue test item towards Oncorhynchys mykiss was investigated according to OECD Guideline 203 under GLP. Fish were exposed to a concentration 100 mg a.i./ for 96 hours. The 96h-NOEC and 96h-LC50 were found to be > 100 mg a.i./l.

 

Short-term toxicity to aquatic invertebrates

A stock solution was prepared by dissolving a known quantity of the sample in a specified volume of dilution water. Test solutions were prepared by adding the stock solution to the dilution water in appropriate quantities. The EC50 (48 h) value was estimated as > 1000 mg/L (equivalent to > 600 a.i./L). The highest NOEC after 48 hours was 560 mg/L (equivalent to 336 mg a.i./L). The LOEC (48 h) could not be determined because only 5 % immobilisation was observed at the highest test concentration of 1000 mg/L.

Long-term toxicity to aquatic invertebrates

The purpose of this study was to assess the toxicity of an analogue test substance dissolved in fresh water, on the reproductive efficacy of Daphnia magna STRAUS - clone 5, in a semi-static test complying with the OECD Guideline No. 211

 

The test criterion of toxicity used was reproductive capacity expressed as the number of neonates per daphnid per day.

 

The nominal concentrations used in the study were as follows: 0,1.6, 4, 10, 25 and 62.5 mg/L. All concentrations given refer to the technical product as supplied by the sponsor.

 

Analytical determinations of the test solutions were made on 6 occasions during the test. The results of the chemical analyses show that the concentrations in the test solutions fresh and used are close to the nominal concentration. All measured concentrations stayed within 80 to 120% of the nominal. Therefore, nominal test substance concentrations are used to calculate the effects.

 

The validity criteria were respected: No mortality occurred in the control group over the test period. The average number of juveniles per parent in the control was 155 after 21 days.

 

The No Observed Effect Concentration (NOEC) is determined as the concentration used in the study that is immediately below the Lowest Observed Effect Concentration (LOEC), the latter derived statistically from the data using the appropriate statistical test. EC10-and EC50-values were determined where possible, using statistical analysis.

 

No significant effects were found up to the highest test concentration on reproduction, parental length or weight using Dunnett’s test. Therefore, the LOEC was found to be > 62.5 mg/L and the NOEC is≥62.5 mg/L (equivalent to 24.06 mg a.i./L).

Algal growth inhibition

Stock cultures were maintained and the tests performed in deionised water with added nutrients. Test item concentrations were 63, 125, 250, 500 and 1000 mg/L in the definitive test. The EC50 (72 h) value was estimated as > 1000 mg/L (equivalent to 600 mg a.i./L) baed on growth rate. Inhibition was only 28 % at 48 hours and 40 % at 72 hours for the highest test concentration.

 

Inhibition of sewage sludge micro-organisms

In order to predict effects of chemicals in the environment and in biological waste water treatment plants, an activated sludge respiration inhibition test was performed. The toxicity of an analogue test item to activated sludge was determined in accordance with OECD Test Guideline 209, and in compliance with the OECD principles of Good Laboratory Practice.

 

Test validity was shown by the EC50 of the reference compound 3,5 -dichlorophenol (15 mg/L), the coefficient of variation of the replicates of the control oxygen uptake rates (10%) and the average oxygen uptake rate for the control replicates (29 mg O2/g dry weight/hour). The toxicity of sodium capryliminodipropionate to activated sludge was determined at a contact time of 3 hours, using various concentrations of the test substance. The inhibitory effect of sodium capryliminodipropionate at a particular concentration was expressed as a percentage of the two controls. From the results EC values were calculated.

The EC50 of sodium capryliminodipropionate for activated sludge after 3 hours contact time was determined to be >640 mg/L (equivalent to 246.4 mg a.i./L. Inhibition of the activated sludge respiration by sodium capryliminodipropionate did not follow a classical dose-response curve and varied from 11% to 19% over the measured concentration range. Sodium capryliminodipropionate was therefore considered not harmful to activated sludge.