2,3,5-trimethylhydroquinone

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: German Standard DIN 38412 L9

Principles of method if other than guideline:

Determination of in vivo chlorophyll a-fluorescence at 685 nm as a measure for the biomass

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

2,3,5-trimethylhydroquinone

EC Number:

211-838-3

EC Name:

2,3,5-trimethylhydroquinone

Cas Number:

700-13-0

Molecular formula:

C9H12O2

IUPAC Name:

2,3,5-trimethylhydroquinone

Details on test material:

- Name of test material (as cited in study report): 2,3,6-Trimethylhydrochinone (synonym: 2,3,6-Trimethylhydrochinone);
no further details on the test substance characteristics given.

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A concentrated stock solution of the test substance in test medium (nominal 1000 mg/l) was prepared using Cremophor (100 mg/l) as a solvent. Then, serial dilutions of this stock solution were prepared to obtain the desired test concentrations. The maximum solvent concentration in the test was 10 mg/l.

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Strain: Scenedesmus subspicatus, Chodat, Strain SAG 86.81
- Source (laboratory, culture collection): Supplier: Sammlung für Algenkulturen, University of Göttingen

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

23 °C

pH:

7.6 - 9.5

Nominal and measured concentrations:

Nominal test concentrations (mg/l):
0.63,
1.25,
2.50,
5.00,
10.0,
20.0,
40.0,
60.0,
control

Details on test conditions:

TEST SYSTEM
- Test vessel: 10 ml flat bottom glass tubes
- Initial cells density: about 10000 cells/ml
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to OECD 201

OTHER TEST CONDITIONS
- Photoperiod: continuous white light

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: fluorimeter, Fluorometric measurement of cell density after 0, 24, 48 72 and 96 hours.

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: fluorescence at 685 nm

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

13 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: fluorescence at 685 nm

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

EC90

Effect conc.:

20 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: fluorescence at 685 nm

Reported statistics and error estimates:

EC50 values were determined with appropriate statistical methods (according to Tallarida & Jacob, 1979).

Any other information on results incl. tables

Growth in % of control
Nominal test  / Exposure time [h]
concentration /
(mg/l)        /   24  /  48    /  72  /   96  / 
Control       / 100.0 / 100.0 / 100.0 / 100.0 /
0.63          / 102.9 / 140.6 / 121.0 / 105.4 /
1.25          / 100.5 / 145.1 / 123.4 / 110.1 / 
2.50          / 107.5 / 138.5 / 117.2 / 107.3 /
5.0           /  94.1 / 114.6 / 101.7 / 103.5 /
10.0          /  63.1 /  58.5 /  67.6 /  86.4 /
20.0          /  26.2 /  14.3 /   9.7 /  14.6 /
40.0          /   4.8 /   0.9 /   0.2 /   0.08
80.0          /   1.3 /   0.3 /   0.06 /  0.0

EC-values after 96 hours:
growth rate
EC20: 11 mg/l
EC50: 15 mg/l
EC90: 26 mg/l

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

The toxicity of trimethylhydroquinone to algae was investigated in a study acc. to DIN 38412 L9. The 72 h EC50 was determined to be 13 mg/L.

Executive summary:

The toxicity of trimethylhydroquinone to algae was investigated in a study acc. to DIN 38412 L9. The effect concentration for biomass is EC₅₀ (72 h) = 13 mg/L that can be used for the hazard assessment.