Reaction mass of sodium 3-{[3-(diethylamino)propyl]carbamoyl}-2-(dodecylamino)propanoate and sodium 3-{[3-(diethylamino)propyl]carbamoyl}-3-(dodecylamino)propanoate

Long-term toxicity to aquatic invertebrates

Description of key information

OECD 211, EU Method C.20, GLP, key study, validity 2:

21d-NOEC = 1.29 mg dry extract/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

1.29 mg/L

Additional information

One key study is available to assess the long-term toxicity of the test item Chimexane HB to Daphnia magna. This study was conducted according to OECD 211 and Commission EC Regulation 440/2008 Method C.20, under semi-static condition with a three times per week renewal of the test solutions. Aim of this study over 21 days was to assess effects on the reproduction capacity and other test item-related effects or parameters such as time of production of first brood, adult mortality, intrinsic rate of natural increase, occurrence of aborted eggs and stillborn juveniles and body length of the parental daphnids.

Nominal concentrations of the test item were selected as follows: 0.128, 0.320, 0.800, 2.00 and 5.00 mg/L, corresponding to the nominal dry extract concentrations of 0.0696, 0.174, 0.435, 1.09 and 2.72 mg/L. The test concentration levels of the test item and the control were analytically verified via LC-MS/MS. The recoveries in the fresh media were determined to be in the range of 95 to 146%. The recoveries in the old media were in the range of 98 to 137%. Therefore, all effect values given are based on the geometric mean measured concentrations of the test item. The geometric mean measured concentrations were calculated to be 0.151, 0.387, 0.971, 2.38 and 5.91 mg/L, corresponding to the geometric mean dry extract concentrations of 0.0821, 0.211, 0.528, 1.29 and 3.22 mg/L.

A statistically significant increase of the reproduction output of 23% in comparison to the control was determined at the geometric mean measured concentration of 2.38 mg/L. The highest concentration level of 5.91 mg/L showed an increase of the reproduction output of 17% in comparison to the control group, which is not statistically significant but biologically noticeable. The determination of endpoint values for the reproduction was not taken into account due to the fact that no reduction of the reproduction was observed.

Related to the total number of produced juveniles (dead + alive) the percentage of dead juveniles and aborted eggs came to a statistically significant maximum of 7% at the geometric mean measured concentration 5.91 mg/L. At this concentration level the mean number of produced juveniles was biologically significant increased in comparison to the control.

Further parameters such as the intrinsic rates of natural increase, the first appearance of juveniles, the number of broods, the growth of the parental daphnids (total body length and dry weight) and the occurrence of males and ephippia were not statistically or biologically significant. These parameters were not used for the assessment of the NOEC/LOEC.

Related to adult mortality, the test item induced biologically significant adult mortality of 60% only at the geometric mean measured concentration of 5.91 mg/L after 21 days. Adult mortality of >20% is seen to be biologically significant. At the other concentration levels from 0.151 to 2.38 mg/L and in the control all parental daphnids survived until the end of the test after 21 days.

The assessment of the endpoints was based on the high mortality of the parental daphnids as adverse effect. The NOEC after 21 days was determined to be 2.38 mg test item/L, corresponding to 1.29 mg dry extract/L,with some statistical uncertainty.