2,5-di-tert-butylhydroquinone

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:

2017 to 2018

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples of the test media were taken at initiation, before and after the test medium renewal and termination.

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

In-house cultures

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

18 to 22°C +/-1°C

Nominal and measured concentrations:

Nominal concentrations: control, 10, 18, 32, 56 and 100 %v/v

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 50 mL
- Aeration:
- Type of flow-through (e.g. peristaltic or proportional diluter):
- Renewal rate of test solution (frequency/flow rate):
- No. of organisms per vessel :5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 5
- No. of vessels per vehicle control (replicates): 4
- Biomass loading rate:

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M7 medium
- Total organic carbon:
- Particulate matter:
- Metals:
- Pesticides:
- Chlorine:
- Alkalinity:
- Ca/mg ratio:
- Conductivity:
- Salinity:
- Culture medium different from test medium:
- Intervals of water quality measurement:

OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod:
- Light intensity:

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

VEHICLE CONTROL PERFORMED: yes/no

RANGE-FINDING STUDY
- Test concentrations:
- Results used to determine the conditions for the definitive study:

Reference substance (positive control):

yes

Remarks:

twice yearly

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.4 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Details on results:

Chemical analysis of the fresh test preparations at 0 and 24 hours showed measured test concentrations to range from 0.26 to 5.4 mg/L. Analysis of the old or expired test preparations at 48 hours showed measured test concentrations had declined, to between less than the limit of quantification (LOQ) which was determined to be 0.017 mg/L and 0.63 mg/L and hence it was considered appropriate to calculate the results based on the geometric mean measured test concentrations in order to give a “worst case” analysis of the data.

Validity criteria fulfilled:

yes

Conclusions:

An acute toxicity study with the freshwater invertebrate, Daphnia magna, was conducted following OECD 202. The test substance was considered to be a "difficult substance" following OECD 2000 guidance and therefore codncetrations were based on %v/v. Therefore, endpoints were reported based on geometric mean measured concentrations. The 48hr EC50 value was 0.4 mg/L.

Executive summary:

An acute toxicity study with the freshwater invertebrate, Daphnia magna, was conducted following OECD 202. The test substance was considered to be a "difficult substance" following OECD 2000 guidance and therefore codncetrations were based on % v/v. Therefore, endpoints were reported based on geometric mean measured concentrations. The 48hr EC50 value was approximately 0.4 mg/L.

Description of key information

An acute toxicity study with the freshwater invertebrate, Daphnia magna, was conducted following OECD 202. The test substance was considered to be a "difficult substance" following OECD 2000 guidance and therefore codncetrations were based on %v/v. Therefore, endpoints were reported based on geometric mean measured concentrations. The 48hr EC50 value was approximately 0.4 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.4 mg/L