2,4,6-trimethylphenol

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant, compliant to the current guideline.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,4,6-trimethylphenol

EC Number:

208-419-2

EC Name:

2,4,6-trimethylphenol

Cas Number:

527-60-6

Molecular formula:

C9H12O

IUPAC Name:

2,4,6-trimethylphenol

Test material form:

solid: crystalline

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Details on test solutions:

Medium preparation
As diluition water, reconstituted water has been used. It has been prepared dissolving the following salts in 1 litre of deionised water:
Bihydrated calcium chloride: 11.76 g/L (batch SLBD4625V)
Eptahydrated magnesium sulphate: 4.93 g/L (batch SLBD3500V)
Acid sodium bicarbonate: 2.59 g/L (batch SLBH4108V)
Potassium chloride: 0.23 (batch SLBC2414V)

25 ml of solution 1,2,3,4 taken to 1000 ml volume with deionised water
For higher volumes the medium has been prepared according to the same proportion.

Test organisms

Test organisms (species):

Daphnia sp.

Details on test organisms:

Daphnia magna straus, Crustacean, Cladocero.
Age: 6-24h
Breeder in Eurofins Biolab Test Facility.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

48 hours

Test conditions

Hardness:

140-250 mg CaCO3/l

Test temperature:

20°C±2°C

pH:

7.83-7.93

Dissolved oxygen:

6.68-7.56

Nominal and measured concentrations:

Nominal concentrations: 0, 1.28, 3.20, 8, 20, 50 mg/L

Details on test conditions:

ASSAY SYSTEM
N. of animals: 20 for each treated - 20 for control
N. of replications: 4 for control and 4 for treated concentration of the definitive test (EC50 test)
N. of concentrations: 5 for range finding test and definitive EC50 test

Maintenance
Culture vessel
Glass beaker (500 ml)
Maintenance in culture
Daphnie have been kept in reconstituted water in the following conditions:
Temperature: 20°C±2°C
Lightning: Photoperiod: 16 hours of light, 8 hours of darkness.
Water hardness: 250 mg CaCO3/l
Type of feeding: Green alga Pseudokirchneriella subcapitata and Saccharomices cervisiae
Water change: 3 times per week

Equipment
- pH-meter O2 meter with microelectrode
- Thermometer
- Incubator
- Laboratory glassware

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

3.403 mg/L

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 2.692-4.3

Reported statistics and error estimates:

Probit Analysis

Any other information on results incl. tables

EC50 was evaluated using EPA Probit Analysis Program Version 1.5.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

The immobilisation of control animals must not be higher than 10% at the end of the test. The conc. of dissolved oxygen ought to be higher than 3 mg/L during the assay. pH must not change more than 1.5 units. Validity criteria have been satisfied.

Conclusions:

Under the test conditions, the 48h Daphnia magna straus EC50 (immobility) of 2,4,6 trimethylphenol is 3.403 mg/L.

Executive summary:

According to OECD 202 and in compliance with GLP, an acute immobilization study was conducted with Daphnia magna. A range-finding test was conducted to determine the test concentrations to be used for the definitive test.

For the definitive test the following concentration were used: 50, 20, 8, 3.2, and 1.28 mg/L and a control. In the definitive study, the test concentration were interpolated from the measured test concentration. The 48 -hour Daphnia magna straus EC50 for immobility was 3.403 mg/L (evaluated using EPA Probit Analysis Program Version 1.5).