Carboxylic acids, di-, C4-6

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

Study period:

1997

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Justification for type of information:

A read-across approach is taken from adipic acid, which is a structural analogue and serves as a good representation for the carboxylic acid mixture.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

GLP compliance:

not specified

Analytical monitoring:

yes

Remarks:

HPLC

Details on sampling:

On Day 0, 7, 14 and 18.

Test organisms (species):

Daphnia magna

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Test temperature:

20 +- 1°C

Nominal and measured concentrations:

nominal: 50.0, 25.0, 12.5, 6.25 and 3.13 mg/L (common ratio: 2.0) and control group

Details on test conditions:

- Number of organisms: 20 animals / concentration (5 animals per test vessel)
- Exposure period: 21 d
- Exposure method: Flow-through type (Continuous supply of test solution)
- Test concentration: 50.0, 25.0, 12.5, 6.25 and 3.13 mg/L (common ratio: 2.0) and control group
- Number of vessels: 4 vessels per concentration
- Test volume: Approx. 1.8 L / vessel
- Test water temperature: 20 +-1°C
- Lighting: Room light, 16 hours light (less than 1200 lux) / 8 hours dark

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

6.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

17.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Details on results:

The results relate to nominal concentrations, based on test substance concentrations.

Any information on pH during the test was not reported. Regarding the effect concentrations, pH effects can be excluded, due to the low range of concentrations.

Conclusions:

A 21d-NOEC of 6.25 mg/L was determined for the test substance towards daphnids under exposure conditions.

Executive summary:

A study was performed to assess the long-term toxicity of adipic acid to Daphnia magna STRAUS under flow-throug conditions in accordance with the OECD Guideline for Testing of Chemicals No. 211 'Daphnia magna, Reproduction Test'.

Daphnia magna were exposed to a range of concentrations (nominal: 50.0, 25.0, 12.5, 6.25 and 3.13 mg/L) and a control for 21 d. 20 daphnis (4 vessels, 5 animals/vessel) were exposed per concentration. The test temperature was 20 +- 1°C.

After 21 d a NOEC of 6.25 mg/L was determined for adipic acid towards daphnids under exposure conditions.

Description of key information

For the mixture no data on long-term toxicity to aquatic invertebrates are availabe. Adipic acid is applied for read-across approach. The long-term toxicity of adipic acid to aquatic invertebrates was determined in a test condicted according to OECD Guideline 211 (Daphnia magna Reproduction Test). A 21d-NOEC of 6.3 mg/L was obtained (MITI, 2002).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

NOEC

Effect concentration:

6.3 mg/L

Additional information

For the mixture no data on long-term toxicity to aquatic invertebrates are available. Adipic acid is applied for read-across approach. Adipic acid is one of the constituents of the dicarboxylic acid mixture. All constituents are homologues linear alkyl dicarboxylic acids with a chain length of four to six carbon atom. The mixture is composed of three discrete carboxylic acids. Due to the structural relationship, adipic acid is a good representative for the dicarboxylic acid mixture. Adipic acid is well assessed on behalf of the ICCA/OECD HPV-program.

The long-term toxicity of adipic acid to aquatic invertebrates was determined in a test condicted according to OECD Guideline 211 (Daphnia magna Reproduction Test). A 21d-NOEC of 6.3 mg/L was obtained. (MITI, 2002).

Any information on pH during the test was not reported. Following the discussion about concentration-dependant decrease of pH, it can be concluded that effects found in this study are likely not due pH effects, based on the low range of concentrations used in this test.