2,2-bis(hydroxymethyl)butanoic 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

Study period:

21-01-1997 to 23-01-1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 and 100 mg/L
- Sampling method: Duplicate samples (50 mL) were taken from the pooled replicates of the control and test concentration at 0 hours and after 48 hours and were analysed using HPLC..
- Sample storage conditions before analysis: Remainder of all samples were stored at 4 °C in case a check analysis was required.

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test substance (100 mg) was dissolved in test water (1 L) to give the desired test exposure level of 100 mg/L.
- Controls: The control group was maintained under identical conditions and contained dilution medium only.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water Flea (Daphnia)
- Strain: Daphnia magna (Straus)
- Source: In-house laboratory cultures
- Age at study initiation: Juveniles (<24 hours old)
- Method of breeding: Parthenogenesis
- Feeding during test: The daphnids received no food during exposure

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

No data provided

Test temperature:

19-20 °C

pH:

6.5-7.7

Dissolved oxygen:

8.5-8.7 mg O2/L

Salinity:

Not applicable. Study was performed in fresh water.

Nominal and measured concentrations:

- Nominal concentration: 100 mg/L
- Measured concentration: 98 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL capacity glass jars containing 200 mL of test medium or diluent medium
- Type: Jars were loosely covered to minimise evaporative losses.
- Aeration: No
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): Duplicate
- No. of vessels per blank control (replicates): Duplicate
- Biomass loading rate: 20 mL test solution/organism

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted medium Elendt M4 prepared using analytical grade reagents and deionised water
- Intervals of water quality measurement: The temperature in each vessel was measured daily and the pH and dissolved oxygen levels were recorded at the start and at the end of the study.

OTHER TEST CONDITIONS
- Photoperiod: 16 hour light: 8 hour dark photoperiod

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Immobilization was recorded at 24 and 48 hours after the start of exposure. The criterion of effect used was that Daphnia were considered to be immobile if they were unable to swim within approximately 15 seconds following gentle agitation of the test vessel.

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 1.0, 10 and 100 mg/L (nominal)
- Results used to determine the conditions for the definitive study: In the range-finding test, no immobilization was observed at any concentration and the ‘no-observed effect level’ was 100 mg/L.

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 98 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: -

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Mortality of control: No

Results with reference substance (positive control):

Not applicable

None

Validity criteria fulfilled:

yes

Remarks:

mortality in control was 0%; dissolved oxygen concentration > 3 mg O2/L

Conclusions:

The 24 and 48-hour EC50 for DMBA to Daphnia magna was > 100 mg/L (nominal). The highest test concentration resulting in 0% immobilisation was 100 mg/L and the lowest test concentration resulting in 100% immobilisation was > 100 mg/L. All results are expressed in terms of nominal concentrations. The mean measured concentration was recorded as 98 mg/L.

Executive summary:

Introduction

A study was performed to assess the acute toxicity of DMBA to Daphnia magna under static exposure conditions. The study was conducted in accordance with EEC Methods for Determination of Ecotoxicity Annex to Directive 92/69/EEC (O.J. No. L383A, 29.12.92) Part C, Method 2 "Acute toxicity to Daphnia" and the OECD Guideline for Testing of Chemicals No. 202, Part I "Daphnia Acute Immobilisation Test”.

 

Methods

A group of twenty, first instar Daphnia, less than 24 hours old, was exposed to a single concentration of DMBA (nominally 100 mg/L dissolved in Elendt M4 medium), for 48 hours. The numbers of immobilised daphnids were recorded for the test and control group after 24 and 48 hours.

 

Results

No immobolisation was recorded in control and test vessels. The 24 and 48-hour EC₅₀ for DMBA to Daphnia magna was > 100 mg/L (nominal). The highest test concentration resulting in 0% immobilisation was 100 mg/L and the lowest test concentration resulting in 100% immobilisation was > 100 mg/L. All results are expressed in terms of nominal concentrations. The mean measured concentration was recorded as 98 mg/L.

Description of key information

A study was performed to assess the acute toxicity of DMBA to Daphnia magna under static exposure conditions. The study was conducted in accordance with EEC Methods for Determination of Ecotoxicity Annex to Directive 92/69/EEC (O.J. No. L383A, 29.12.92) Part C, Method 2 "Acute toxicity to Daphnia" and the OECD Guideline for Testing of Chemicals No. 202, Part I "Daphnia Acute Immobilisation Test”.

 

A group of twenty, first instar Daphnia, less than 24 hours old, was exposed to a single concentration of DMBA (nominally 100 mg/L dissolved in Elendt M4 medium), for 48 hours. The numbers of immobilised daphnids were recorded for the test and control group after 24 and 48 hours.

 

No immobolisation was recorded in control and test vessels. The 24 and 48-hour EC₅₀ for DMBA to Daphnia magna was > 100 mg/L (nominal). The highest test concentration resulting in 0% immobilisation was 100 mg/L and the lowest test concentration resulting in 100% immobilisation was > 100 mg/L. All results are expressed in terms of nominal concentrations. The mean measured concentration was recorded as 98 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

> 100 mg/L