Sodium 2-heptyl-2,3-dihydro-3-(2-hydroxyethyl)-1H-imidazole-1-propionate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

48 hours

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Test substance name Crodateric CYAP
Scymaris reference number 1014TS047
Physical state and appearance Dark solid
Supplier Croda Europe Ltd.
Lot/batch number PS-196-555

Analytical monitoring:

yes

Vehicle:

yes

Remarks:

Culture medium. The reconstituted water medium used for testing (and maintenance of stock cultures) was Elendt's M4 D. magna medium

Details on test solutions:

This study was run with a dilution water control and nominal exposure concentrations of 6.25, 12.5, 25, 50 and 100 mg/L.
A primary stock concentrate of Crodateric CYAP, with a nominal concentration of 100 mg/L, was prepared by adding a nominal 0.2 g (actual weight: 0.19992 g) of test substance to 2000 mL of culture medium. The stock was then stirred for 27 minutes. The resultant stock was observed to be clear and colourless with no particles visible and was used to prepare the test solutions. This was achieved by the direct addition of the appropriate amount of concentrate to dilution water in a volumetric flask. The 100 mg/L stock concentrate was also dispensed directly to the 100 mg/L test concentration test vessels. The control consisted of culture medium only. After approximately 15 minutes stirring, all test solutions were observed as clear and colourless with no particles visible

Test organisms (species):

Daphnia magna

Details on test organisms:

The test organism was the freshwater crustacean, Daphnia magna, obtained from continuous laboratory cultures held at Scymaris.
The stock cultures of D. magna were maintained in a reconstituted water medium, the same as the test dilution water, at a temperature of 20 ± 2°C. The cultures were maintained in 2 L glass vessels with a working volume of 1.6 L. A photoperiod of 16 hours’ light:8 hours dark, with 20-minute transition periods was provided.
The D. magna cultures were fed on a mixed algae diet of Chlorella vulgaris, strain CCAP 211/12 and Pseudokirchneriella subcapitata, strain CCAP 278/4. The D. magna cultures were fed daily ad libitum depending on age and density of the culture. Culture conditions were such that the D. magna reproduction was by diploid parthenogenesis.
D. magna <24 hours old, obtained from a single culture vessel, were used for testing. The parent animals were 18  1 days old and had been maintained with a twice weekly renewal of reconstituted water medium since birth. The test organisms and the cultures from which they were obtained showed no evidence of disease before the test period

Test type:

static

Water media type:

other: Elendt's M4 D. magna medium

Total exposure duration:

48 h

Hardness:

236.7 mg/l as CaCO3

Test temperature:

20 +/- 1C

pH:

7.74

Conductivity:

623 µS/cm

Nominal and measured concentrations:

This study was run with a dilution water control and nominal exposure concentrations of 6.25, 12.5, 25, 50 and 100 mg/L
Control and mean measured concentrations of 5.6, 11, 20, 41 and 88 mg/L

Reference substance (positive control):

yes

Remarks:

Dilution water control

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 88 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 88 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

There was no immobility observed in the dilution water control. At the 48 hour time point, one Daphnia in the 41 mg/L test concentration appeared inactive compared to the control and only mobile upon gentle agitation of the test vessel. At 48 hours, all remaining mobile Daphnia in the 88 mg/L test concentration appeared less active and slow moving compared to the control.

Validity criteria fulfilled:

yes

Conclusions:

Based on immobility compared to the control (p <0.05) the 48 hour No Observed Effect Concentration (NOEC) was determined to be
88 mg/L and the Lowest Observed Effect Concentration (LOEC) was >88 mg/L.

Description of key information

Based on immobility compared to the control (p <0.05) the 48 hour No Observed Effect Concentration (NOEC) was determined to be

88 mg/L and the Lowest Observed Effect Concentration (LOEC) was >88 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

88 mg/L