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Ecotoxicological information

Toxicity to microorganisms

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Administrative data

Endpoint:
toxicity to microorganisms
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Conducted on 19 November 1996
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: done under GLP and OECD method

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report Date:
1997

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: EC Directive 88/302 'Biodegradation-Activated Sludge Respiration Inhibition test' and OECD guideline No.209'
Principles of method if other than guideline:
The study was conducted in accordance with OECD Guideline for Testing of Chemicals No. 209 and EEC Methods for the Determination of Ecotoxicity, EEC Directive 67/548 Annex VIII Part C (87/302/EEC), Activated Sludge, Respiratiqn Inhibition Test
Cultures of activated sewage sludge were incubated with synthetic sewage under vigorous aeration and in the presence of the test substance. Aeration was interrupted after 3 hours and the rates of respiration measured electrochemically for each culture. Percentage inhibition of respiration was calculated for each culture after a 3 hour contact period by comparing oxygen depletion rates for the test substance with those for the negative control culture
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
Intended use: Pharmaceutical intermediate
Appearance: White powder
Storage conditions: In darkness at room temperature
Expiry: Not supplied
Purity: >97 %
Date received: 2 October 1996
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
REFERENCE SUBSTANCE

Identity

3,5-Dichlorophenol (C6H3Cl2.0H)
Aldrich Chemical Co Ltd, Batch no. 41205, Purity 97%.

The reference substance was dissolved in dilution water with the aid of ultrasonic disruption

Sampling and analysis

Analytical monitoring:
no
Details on sampling:
check if analytical sampling done to verify concnetration

Test solutions

Vehicle:
no
Details on test solutions:
Test substance concentrations: 100mg/l in duplicate of test substance was dissolved directly in test water without the aid of auxiliary solvents or dispersing agents, with the aid of ultrasonic disruption

Reference substance: 3.2, 10 and 32 mg/l.
At time "O", 16 ml of synthetic sewage was made up to 300 ml with water in a 1 litre glass beaker. 200 ml of inoculum was added and the mixture aerated at approximately 0.5 - 1 litre per minute with compressed air via a narrow bore glass tube. This preparation was designated Control R1 Thereafter, at 15-minute intervals, further cultures were prepared following the same procedure but with the addition of appropriate amounts of test or reference substance to the vessels prior to adjusting the volume and adding the inoculum.

Test organisms

Test organisms (species):
sewage, domestic
Details on inoculum:
Type: A mixed population of activated sewage sludge micro-organisms.
Source: The aeration stage of the Anglian Water (Godmanchester) sewage treatment plant treating predominantly domestic sewage.
Preparation: A sample of activated sewage sludge was collected from the sewage treatment plant on 18 November 1996. The sample was maintained at 20°C with continuous aeration and used within 24 hours of collection. The pH was 7.9 and the suspended solids level of the sample was 7.2 g/l. Consequently, it was necessary to dilute the inoculum by a factor of two to obtain a suspended solid content of 3.6 g/l, to be within the 2 - 4 g/l range specified in the guidelines.




DILUTION WATER

Type


Laboratory tap water, dechlorinated by passage through activated carbon and softened by reverse osmosis (hardness approximately 120 - 180 mg/I as CaC03 , pH 7.5 ± 0.5).

Study design

Test type:
other: activated sewage sludge were incubated with synthetic sewage under vigorous aeration and in the presence of the test substance
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
3 h
Post exposure observation period:
As each culture reached 3 hours contact time its pH was recorded and the rate of respiration measured. A 280 ml darkened glass BOD bottle was completely filled with the culture and sealed by the Yellow Springs Dissolved Oxygen Meter (Model No. 57) dissolved oxygen probe whilst being stirred by a magnetic stirrer. The dissolved oxygen level was recorded for approximately 10 minutes (between approximately 6.5 and 2.5 mg02/l). Separate measuring bottles were used for control, test and reference cultures to eliminate the possibility of cross-contamination

Test conditions

Hardness:
No data
Test temperature:
21 °C
pH:
no data in report but was recorded
Dissolved oxygen:
dissolved oxygen level was recorded for approximately 10 minutes (between approximately 6.5 and 2.5 mg02/l).
Salinity:
No Data
Nominal and measured concentrations:
UK-143,108:

3,5-dichlorophenol:
EC50 (3 hours):> 100 mg/I.
EC50 (3 hours):13 mg/l

Details on test conditions:
TEST SYSTEM: series
- Test vessel: 1 liter glass beaker
- Aeration: yes
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

test has test substance+synthetic sewage + inoculumn
controls has synthetic sewage + inoculumn only

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Laboratory tap water, dechlorinated by passage through activated carbon and softened by reverse osmosis (hardness approximately 120 - 180 mg/I as CaC03 , pH 7.5 ± 0.5).
TEST CONCENTRATIONS
- Test concentrations: Test substance: 100 mg/l in duplicate. Reference substance: 3.2, 10 and 32 mg/l.
Reference substance (positive control):
yes
Remarks:
3.5 dichlorophenyl

Results and discussion

Effect concentrationsopen allclose all
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
> 0 - < 100 mg/L
Remarks on result:
other: UK-143,108
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
13 mg/L
Remarks on result:
other: 3,5-dichlorophenol
Details on results:
Variation in respiration rates of Controls 1 and 2: ± 2 % .

Results with reference substance (positive control):
3,5-dichlorophenol:EC50 (3 hours): 13 mg/I
Reported statistics and error estimates:
No Data

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
The validation criteria for (i) Control culture respiration and (ii) respiration inhibition by the reference substance, were fulfilled during this study
Conclusions:
The EC50 (respiration inhibition) value for UK-143, 108 with activated sewage sludge has been determined as > 100 mg/I for the 3 hour contact time.