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Ecotoxicological information

Toxicity to microorganisms

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Administrative data

Endpoint:
activated sludge nitrification inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: endpoint study record was created to contribute to the overall results; acceptable, well documented publication which meets basic scientific principles

Data source

Reference
Reference Type:
publication
Title:
A database of chemical toxicity to environmental bacteria and ist use in interspecies comparisons and correlations
Author:
Blum DJW and RE Speece
Year:
1991
Bibliographic source:
Research Journal WPCF 63(3): 198-207

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
other: Test with Methanogens by Owen, 1979 (Owen, W.F.: Bioassay for Monitoring Biochemical Methane Potential and Anaerobic Toxicity. Water Res. 13, 485, 1979)
Deviations:
not specified
Qualifier:
equivalent or similar to guideline
Guideline:
ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)
Version / remarks:
Test with aerobic heterotrophs (Inhibition of respiration; prolonged incubation compared to ISO 8192)
Deviations:
not specified
Qualifier:
according to guideline
Guideline:
ISO 9509 (Toxicity test for assessing the inhibition of nitrification of activated sludge microorganisms)
Deviations:
not specified
Qualifier:
according to guideline
Guideline:
other: Test with Photobacterium phosphoreum (Microtox test by Microbics Corp.); data from Kaiser and Ribo (1987)
Deviations:
not specified
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
1,3-dichlorobenzene
EC Number:
208-792-1
EC Name:
1,3-dichlorobenzene
Cas Number:
541-73-1
Molecular formula:
C6H4Cl2
IUPAC Name:
1,3-dichlorobenzene
Test material form:
other: liquid

Sampling and analysis

Analytical monitoring:
not specified

Test organisms

Test organisms (species):
other: See "Details on inoculum"
Details on inoculum:
1-Methanogens
2-Aerobic heterotrophs
3-Nitrosomonas
4-Photobacterium phosphoreum

Results and discussion

Effect concentrationsopen allclose all
Duration:
5 min
Dose descriptor:
IC50
Remarks:
Photobacterium phosphoricum
Effect conc.:
3.1 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth inhibition
Remarks on result:
other: method: bioluminiscence
Duration:
24 h
Dose descriptor:
IC50
Remarks:
Nitrosomas
Effect conc.:
93 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of nitrification rate
Remarks on result:
other: ammonia use
Duration:
48 h
Dose descriptor:
IC50
Remarks:
Methanogens
Effect conc.:
260 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of anaerobic gas production
Duration:
24 h
Dose descriptor:
IC50
Remarks:
aerobic heterotrophhics
Effect conc.:
720 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of heterotrophic respiration

Any other information on results incl. tables

 Results:

 Organism  Measure of activity  pH value  Atmosphere  Temperature  Exposure time  IC50
     initial  °C  minutes  hours  mg/L
Photobacteriumphosphoreum    bioluminiscence   6.5 - 7.5  atmosphere  15  5   3.1 
Nitrosomas   ammonia use  6.5 - 8.0  atmosphere + 25 mL O21.6 N2 : 1 O2 25    24   93
Methanogens  gas production  7  2 N2 : 1 O2  35   24, 48, 72, 96   260(48h)
Aerobic heterotrops

 oxygen consumption

 7  atmosphere + 50 mL O21 N2 : 1 O2  25, 35    15, 27, 38, 49  720*(24 h)

* estimated

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Conclusions:
The toxicity to bacteria of 1,3-dichlorobenzene were determined at various species and various measurement of activity. Photobacterium phosphoreum showed an IC50 (bioluminiscence) of 3.1 mg/L after 5 minutes. Nitrosomas showed an IC50 (ammonia use) of 93 mg/L after 24 hours. Methanogens showed an IC50 (gas production of 160 mg/L after 48 hours and aerobic heterotrops an IC50 (oxygen consumption) of 720 mg/L after 48 hours (this value is estimated).
Executive summary:

The toxicity to bacteria of 1,3-dichlorobenzene were determined at various species and various measurement of activity according to four methods.

Photobacterium phosphoreum was determined with the method "Microtox test by Microbics Corp." (data from Kaiser & Ribo, 1987) and showed an IC50 (bioluminiscence) of 3.1 mg/L after 5 minutes.

Nitrosomas was determined with the method ISO DIS 9509 "Method for Assessing the Inhibition of Nitrification of Activated Sludge Microorganisms by Chemicals and Waste Waters" and showed an IC50 (ammonia use) of 93 mg/L after 24 hours.

Methanogens was determined with the method "Test with Methanogens by Owen, 1979" and showed an IC50 (gas production of 160 mg/L after 48 hours.

Aerobic heterotrops was determined with the method ISO 8192 "Test for Inhibition of Oxygen Consumption by Activated Sludge" and showed an IC50 (oxygen consumption) of 720 mg/L after 48 hours (this value is estimated).