Adipic acid

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

not specified

Analytical monitoring:

yes

Remarks:

HPLC

Details on sampling:

At the start of exposure and at the end of exposure

Vehicle:

not specified

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20 +- 1°C

pH:

no data

Dissolved oxygen:

no data

Nominal and measured concentrations:

nominal: 100, 76.9, 59.2, 45.5, 35 mg/L (ratio 1.3), control

Details on test conditions:

- Number of organisms: 20 animals / concentration (5 animals per test vessel)
- Exposure period: 48 h
- Exposure method: static
- Test concentration: 100, 76.9, 59.2, 45.5, 35 mg/L (ratio 1.3), control
- Number of vessels: 4 vessels per concentration
- Test volume: 200 mL / vessel
- Test water temperature: 20 +-1°C
- Lighting: Room light, 16 hours light / 8 hours dark

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

46 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: immobilization

Details on results:

The effect concentrations relate to nominal concentrations.

Conclusions:

A 48h-EC50 of 46 mg/L was determined for the adipic acid towards daphnids under exposure conditions.

Executive summary:

A study was performed to assess the acute toxicity of adipic acid to Daphnia magna STRAUS under static conditions in accordance with the OECD Guideline for Testing of Chemicals No. 202 'Daphnia sp., Acute Immobilisation Test'.

Daphnia magna were exposed to a range of concentrations (nominal: 100, 76.9, 59.2, 45.5, 35 mg/L) and a control for 48 h. 20 daphnis (4 vessels, 5 animals/vessel) were exposed per concentration. The test temperature was 20 +- 1°C.

After 48 h an EC50 of 46 mg/L was determined for adipic acid towards daphnids under exposure conditions.

Description of key information

A study was performed to assess the acute toxicity of adipic acid to Daphnia magna STRAUS under static conditions in accordance with the OECD Guideline for Testing of Chemicals No. 202 'Daphnia sp., Acute Immobilisation Test'.

Daphnia magna were exposed to a range of concentrations (nominal: 100, 76.9, 59.2, 45.5, 35 mg/L) and a control for 48 h. 20 daphnis (4 vessels, 5 animals/vessel) were exposed per concentration. The test temperature was 20 +- 1°C.

After 48 h an EC50 of 46 mg/L was determined for adipic acid towards daphnids under exposure conditions.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

46 mg/L

Additional information

With the invertebrate Daphnia magna one acute test according to the European guideline 79/831/EEC, method C.2 is available. For a test period of 24 hours an EC50 value of 85.6 mg/l was obtained. The same effect concentration was reported after a test period of 48 hours (BASF AG 1988b). pH values in the test solutions ranged from 4 (500 mg/l) to 7.7 (15.6 mg/l) and pH related effects on the daphnids cannot be excluded.

This study on daphnids was characterized by a concentration-dependant decrease of pH. During the test on Daphnia, the treatments testing adipic acid's concentrations near the EC50 value presented a pH markedly inferior to the control treatment. At the end of the 48-hour exposure period, the pH in the control treatment was 7.95, whereas it decreased from 7.2 to 5.26 in the range of concentrations (62.5 - 125 mg/L) covering the EC50 value (85.6 mg/L). Furthermore, it should be noticed that the pH value in the control treatment is high compared to the guideline's requirements. Based on this observation, a pH effect cannot be ruled out when considering the toxicity reported in this study.

Describing the toxicity towards aquatic invertebrates, the study conducted by the National Institute of Technology and Evaluation, Japan is preferred, despite deficiencies in study documentation concerning pH.