1,3-dichlorobenzene

Toxicity to microorganisms

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 guideline

Test guideline 1

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

Test guideline 2

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

Test guideline 3

Qualifier:

according to guideline

Guideline:

ISO 9509 (Toxicity test for assessing the inhibition of nitrification of activated sludge microorganisms)

Deviations:

not specified

Test guideline 4

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

Test material information

Constituent 1

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:

liquid

Remarks:

Colourless transparent 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 concentrations

Effect concentrations 1

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

Effect concentrations 2

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

Effect concentrations 3

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

Effect concentrations 4

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).