Amides, C8-18 (even numbered) and C18-unsatd., N-(hydroxyethyl)

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

September, 2021 to October, 2022

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Refer to the section 13 for details on the category justification.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Version / remarks:

2012

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Samples will be taken from the control and each surviving test group from freshly prepared test
solutions (without food) and the corresponding aged test solutions (with food). Replicate vessels
will be pooled to give one sample. Sampling of the test solutions will start with day 0 samples
and will be performed at least once per week throughout the test. Two renewal periods of 48
hours and one renewal period of 72 hours (weekend) will be chosen for sampling.

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

The study was performed with young daphnids of the species Daphnia magna Straus, which
is the preferred test species recommended by the test guideline. A clone of this species was
originally supplied by Daphnia Collection of the University of Basel/Switzerland in 2015. The
clone is successfully bred at IES Ltd under temperature and light conditions identical to those of
the test.
Each stock animal was maintained separately in a 100 mL glass beaker filled with about 80 mL
Elendt M7 medium and was transferred twice a week to fresh medium. During the culturing period,
the parental daphnidswere fed three times a week with an algal suspension and a Tetramin®
suspension. Details are documented in the culturing records. Culture conditions ensure that
reproduction will be by parthenogenesis.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Post exposure observation period:

None

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

2.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

other: Mortality and inhibition of reproduction

Details on results:

See attachment.

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, the NOEC was equivalent to 2.2 mg/L (Loading Rate) based on mortality and inhibition of reproduction.

Executive summary:

A study was conducted to evaluate the potential toxicity of the read across substance amides, C12-18 and C18-unsatd., N-(hydroxyethyl) on the survival, growth, and reproduction of Daphnia magna during the exposure period of three weeks. The daphnids were exposed in a semi-static test to aqueous test media containing the test substance at various concentrations. The mortality, reproduction, and body length of the daphnids, as well as the intrinsic rate of reproduction, at the different test concentrations were compared with the corresponding parameters in the control. Additionally, the test animals were observed for visible abnormalities. Under the study conditions, the NOEC was equivalent to 2.2 mg/L (Loading Rate) based on mortality and inhibition of reproduction (Dupont, 2022).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

NOEC

Effect concentration:

2.2 mg/L

Additional information

A study was conducted to evaluate the potential toxicity of the read across substance amides, C12-18 and C18-unsatd., N-(hydroxyethyl) on the survival, growth, and reproduction of Daphnia magna during the exposure period of three weeks. The daphnids were exposed in a semi-static test to aqueous test media containing the test substance at various concentrations. The mortality, reproduction, and body length of the daphnids, as well as the intrinsic rate of reproduction, at the different test concentrations were compared with the corresponding parameters in the control. Additionally, the test animals were observed for visible abnormalities. Under the study conditions, the NOEC was equivalent to 2.2 mg/L (Loading Rate) based on mortality and inhibition of reproduction (Dupont, 2022).