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Ecotoxicological information

Toxicity to microorganisms

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Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
other information
Study period:
19.06.1998
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1998
Report Date:
1998

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
Batch: 351681/1796 (deliverd by Fluka)
water solubility: mixable in any relation till 10 g/L
purity: 98 %
Homogeneity: homogeneous
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
no data available

Sampling and analysis

Analytical monitoring:
no
Details on sampling:
no data available

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
activated sludge, domestic
Details on inoculum:
Activated sludge from laboratory wastewater treatment plants fed with municipal and synthetic wastewater. The inoculum was washed, brought to a concentration of 5 g/L dry substance and aerated for 24 hours. 50 ml were added to a test 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:
yes
Total exposure duration:
30 min
Post exposure observation period:
no data available

Test conditions

Hardness:
no data available
Test temperature:
20 +/- 2 °C
pH:
no data available
Dissolved oxygen:
> 2.5 mg/L during aeration
>6.5 mg/L immidiately before measurement
Salinity:
no data available
Nominal and measured concentrations:
nominal concentration of 1000 mg/L
Details on test conditions:
Stock solution
Name input (g)
Test substance Methoxyessigsäure 2 g/L
Reference substance 3,5-dichlorophenol 0.5 g/L

Synthetic medium: 8 mI/vessel 100-fold concentrated OECD Medium
The pH value has been measured and adjusted to pH 7.0 - 8.0 before the addition of activated sludge.
Reference substance (positive control):
yes
Remarks:
3,5-dichlorophenol

Results and discussion

Effect concentrations
Duration:
30 min
Dose descriptor:
EC50
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Results with reference substance (positive control):
The IC50 for 3,5-dichlorophenol was ca. 12 mg/L.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Based on the results of this study the IC50 of Methoxyacetic acid on activated sludge is > 1000 mg/L.
Executive summary:

This study was designed to determine the effects of Methoxyacetic acid on sewage sludge micro-organisms by measuring the respiration rate after exposure to the test substance after a 30 min contact time. Based on the results of this study the EC50 of Methoxyacetic on activated sludge is higher than 1000 mg/L.