3,4,5-trimethoxytoluene

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes

Test material

Test material information

Constituent 1

Details on test material:

- Name of test material (as cited in study report): 3,4,5-Trimethoxytoluol
- Physical state: yellowish, solid
- Analytical purity: 96.6%
- Impurities (identity and concentrations): 3-Brom-4,5-dimethoxytoluol: 0.6%; Wasser : 0.15%
- Lot/batch No.: 30364/143
- Storage condition of test material: room temperature

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test substance was added in the required amount to the test vessel with about 180 ml deionized water. The mixture was stirred for 22 ± 2 h to obtain an optimal solution. Then synthetic medium was added , the pH-value was adjusted to 7.5 ± 0.5.

Test organisms

Test organisms (species):

activated sludge

Details on inoculum:

- Preparation of inoculum for exposure: The inoculum was washed, brought to a concentration of 5 g/L dry substance and aerated during the night . 50 ml were added to a total volume of 250 ml to obtain a concentration of 1 g/L dry substance in the test.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

180 min

Test conditions

Test temperature:

20 ± 2 °C

pH:

7.2-8.0

Nominal and measured concentrations:

Nominal test concentrations: 110, 513, 1031 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, nominal volume, fill volume: Erlenmeyer-vessel, 250 ml, 250 ml
- Synthetic medium: 8 ml/vessel 100-fold concentrated OECD medium
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 3
- Biomass loading rate: 1 g/L dry substance

EFFECT PARAMETERS MEASURED: respiration rate after 180 min

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

180 min

Dose descriptor:

other: EC20

Effect conc.:

ca. 590 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 2

Duration:

180 min

Dose descriptor:

EC50

Effect conc.:

ca. 920 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 3

Duration:

180 min

Dose descriptor:

other: EC80

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Results with reference substance (positive control):

Effect concentrations (180 min):
EC20 = ca. 1.7 mg/L
EC50 = ca. 12 mg/L
EC80 = ca. 66 mg/L