(3E)-1,7,7-trimethyl-3-(4-methylbenzylidene)bicyclo[2.2.1]heptan-2-one

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Limited method details provided and no details of whether analysis of test concentrations was conducted.

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

not specified

GLP compliance:

not specified

Remarks:

Published study from a peer-reviewed journal.

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

Daphnia magna

Test type:

semi-static

Water media type:

not specified

Limit test:

no

Total exposure duration:

21 d

Nominal and measured concentrations:

Nominal concentrations: 1.28, 3.2, 8, 20 and 50 μg/L

Details on test conditions:

TEST SYSTEM
- Renewal rate of test solution (frequency/flow rate): Renewal of medium took place every 48 hours.

EFFECT PARAMETERS MEASURED: The offsprings produced by each parent animal were counted daily.

Reference substance (positive control):

not specified

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

50 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks:

and body length

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

20 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks:

and body length

Validity criteria fulfilled:

not specified

Conclusions:

Reproduction and body length were reduced at 50 μg/L test item. No adverse effects on either the number or sex of offsprings or body size were observed up to 20 μg/L test item.

Executive summary:

The chronic toxicity of 3-(4-methylbenzylidene-camphor) to Daphnia magna was determined in a 21-day test conducted according to OECD Guideline 211. Test organisms were exposed to five nominal concentrations of 1.28, 3.2, 8, 20 and 50 μg/L 3-(4-methylbenzylidene-camphor) under semi-static conditions with media renewal every 48 hours. The offspring produced by each parent animal were counted daily. Reproduction and body length were reduced at 50 μg/L test item. No adverse effects on either the number or sex of offspring or body size were observed up to 20 μg/L test item. This study is considered to be reliable with restrictions (Klimisch 2) as limited method details are provided and no details are reported of whether analysis of test concentrations was conducted.

Description of key information

No adverse effects on either the number or sex of offsprings or body size of Daphnia magna were observed up to 20 μg/L test item (nominal concentration).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

20 µg/L

Additional information

The chronic toxicity of 3-(4-methylbenzylidene-camphor) to Daphnia magna was determined in two 21-day studies conducted according to OECD Guideline 211. In the first study, test organisms were exposed to five nominal concentrations of 1.28, 3.2, 8, 20 and 50 μg/L under semi-static conditions with media renewal every 48 hours. The offspring produced by each parent animal were counted daily. Reproduction and body length were reduced at 50 μg/L test item. No adverse effects on either the number or sex of offspring or body size were observed up to 20 μg/L test item. This study is considered to be reliable with restrictions (Klimisch 2) as limited method details are provided and no details are reported of whether analysis of test concentrations was conducted (2010).

In the second study, test organisms were exposed to five nominal concentrations of 0.013, 0.025, 0.05, 0.1, 0.2 mg/L test item under semi-static conditions with media renewal twice a week. The reproductive output was analysed daily by counting the number of living offspring per parent animal. The time of first release of neonates was also recorded and the body length of parent daphnids were measured at the end of the test. The test item did not affect the number of released neonates significantly at nominal concentrations up to 0.2 mg/L. However, the length of the parental animals was significantly decreased (p < 0.01) after 21 d at the highest nominal test concentration (0.2 mg/L). The time-weighted mean concentrations of 0.13 and 0.2 mg/L nominal concentrations were determined to be 0.058 and 0.07 mg/L, respectively. This study is considered to be reliable with restrictions (Klimisch 2), as the test renewal frequency was not sufficient to maintain the test concentrations and the full analytical verification results were not reported (2011).

Both studies show adverse effects on body length in the range 0.050 (nominal) to 0.070 (TWA) mg/L test item. Adverse effects on reproductive success were also observed in one study at 0.050 mg/L test item (nominal), however no effects on reproduction were observed in the second study up to 0.070 mg/L test item (TWA), the highest concentration tested. The NOEC is therefore considered to be 0.020 mg/L test item (nominal). Although the effects on reproduction were not confirmed in the second study, the NOEC is also relevant to Daphnia reproduction as the worst-case scenario.