1,2-dichloro-3-nitrobenzene

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms, other

Type of information:

other: applicant's summary entry

Adequacy of study:

other information

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Principles of method if other than guideline:

applicant's summary entry

GLP compliance:

not specified

Activated sludge

Bayer AG, 1990

Reliability: 2; Rational for reliability: Guideline study with acceptable restrictions.

The toxicity of 2,3-dichloronitrobenzene to activated sludge was tested under GLP compliance according to the method ISO 8192-1986. A defined amount of activated sludge (6 g/l) was mixed with a synthetic nutrient solution and the respiration rate was measured. The respiration rates at different test substance concentrations were compared. Activated sludge used in the experiment was originated from the laboratory sewage treatment plant, its sensitivity was reviewed with the reference substance 3,5-dichlorophenol. Examined 2,3-dichlorobenzene had a purity of 99.6% and was tested in the following concentrations: 100, 180, 320, 560, and 1000 mg/l. However at concentrations exceeding 100 mg/l 2,3-dichloronitrobenzene was not completely soluble in water anymore. Accompanying analytical measurements of the test substance were not performed. Based on nominal concentrations an EC50 of 592 mg/l was determined.

 

Photobacterium phosphoreum

 

Deneer et al., 1989

Reliability: 2; Rational for reliability: Study according to standard procedure. Basic data given.

The test with Photobacterium phosphoreum, and calculations of concentrations causing 50% reduction of bioluminescence after 15 min of exposure were carried out as described in the Beckman Instruments Manual (1982). Test concentrations increased geometrically with a factor of 3.2. The effective concentration was calculated on the basis of added amounts of test material. The 15-min EC50 determined was 1.5 mg/l. This value closely corresponds to the value given by Kaiser and Ribo (1985). Since they determined a 30-min EC50 value the distribution of the test substance between the aqueous phase and the bacteria apparently proceeds very rapidly. This was also observed by Ribo and Kaiser (1983), who found that the differences between 5-, 15- and 30-min EC50 values for a number of chlorinated phenols and benzenes were very small compared to experimental error for compounds with log P up to 5.

 

Kaiser and Ribo, 1985

Reliability: 2; Rational for reliability: Study according to standard procedure. Basic data given.

The acute toxic concentration (EC50) of 2,3-dichloronitrobenzene to the luminescent Photobacterium phosphoreum was determined with the Microtox test system. The bioassay was performed with some minor changes according to the procedure described by the instrument manufacturer (Beckman Instruments, Inc., Microtox TM System Operating Manual, 1982). Following that procedure, the light emitted by aliquot volumes of the suspension of the reconstituted bacteria, was recorded before and 5, 15 and 30 minutes after the addition of the sample solution. The test was run at least three times, taking as final value the mean of the values falling within the 20% deviation limits after the data reduction. The concentration causing a 50% reduction of the light emitted after 30 minutes of exposure, are reported as the toxicity values for the compound: 30 min-EC50 = 1.46 mg/l.

 

Maas-Diepeveen and van Leeuwen, 1986

Rel. 2; Rational for reliability: Study according to standard procedure. Basic data given.

The test with Photobacterium phosphoreum (Microtox test: Beckman, model 2055) and the calculation of the EC50 value were carried out in accordance with the procedure described in the Beckman Instruments Manual (1982). Tested 2,3-dichloronitrobenzene had a purity of > 98%. The stock solution of the compound was prepared in dimethylsulfoxide (DMSO; Merck, purity 99%). After an exposure period of 15 minutes an EC50 of 1.5 mg/l (95%C.L. 1.4-1.6) was found.

 

Tetrahymena pyriformis

 

Schultz, 1999

Rel. 2; Rational for reliability: Basic data given.

Population growth impairment testing with the common ciliate Tetrahymena pyriformis (strain GL-C) was conducted following the protocol described by Schultz (1997). This 40-h assay is static in design and uses population density quantitated spectrophotometrically at 540 nm as its end point. The test substance was tested in three replicates. Each test replicate consisted of six to eight different concentrations with duplicate flasks with each concentration. Only replicates with control absorbency values of > 0.6 but < 0.75 were used in the analysis. Two controls were used. In the test an IC50 of 233.5 mg/l was determined.

Description of key information

For transported isolated intermediates according to Reach, Annex XVIII, this endpoint is not a data requirement. However, data is available for this endpoint and is thus reported under the guidance of "all available data".

Other applicant's summary, 2009

Activated sludge

Bayer AG, 1990

Reliability: 2; Rational for reliability: Guideline study with acceptable restrictions.

The toxicity of 2,3-dichloronitrobenzene to activated sludge was tested under GLP compliance according to the method ISO 8192-1986. A defined amount of activated sludge (6 g/l) was mixed with a synthetic nutrient solution and the respiration rate was measured. The respiration rates at different test substance concentrations were compared. Activated sludge used in the experiment was originated from the laboratory sewage treatment plant, its sensitivity was reviewed with the reference substance 3,5-dichlorophenol. Examined 2,3-dichlorobenzene had a purity of 99.6% and was tested in the following concentrations: 100, 180, 320, 560, and 1000 mg/l. However at concentrations exceeding 100 mg/l 2,3-dichloronitrobenzene was not completely soluble in water anymore. Accompanying analytical measurements of the test substance were not performed. Based on nominal concentrations an EC50 of 592 mg/l was determined.

 

Photobacterium phosphoreum

Deneer et al., 1989

Reliability: 2; Rational for reliability: Study according to standard procedure. Basic data given.

The test with Photobacterium phosphoreum, and calculations of concentrations causing 50% reduction of bioluminescence after 15 min of exposure were carried out as described in the Beckman Instruments Manual (1982). Test concentrations increased geometrically with a factor of 3.2. The effective concentration was calculated on the basis of added amounts of test material. The 15-min EC50 determined was 1.5 mg/l. This value closely corresponds to the value given by Kaiser and Ribo (1985). Since they determined a 30-min EC50 value the distribution of the test substance between the aqueous phase and the bacteria apparently proceeds very rapidly. This was also observed by Ribo and Kaiser (1983), who found that the differences between 5-, 15- and 30-min EC50 values for a number of chlorinated phenols and benzenes were very small compared to experimental error for compounds with log P up to 5.

 

Kaiser and Ribo, 1985

Reliability: 2; Rational for reliability: Study according to standard procedure. Basic data given.

The acute toxic concentration (EC50) of 2,3-dichloronitrobenzene to the luminescent Photobacterium phosphoreum was determined with the Microtox test system. The bioassay was performed with some minor changes according to the procedure described by the instrument manufacturer (Beckman Instruments, Inc., Microtox TM System Operating Manual, 1982). Following that procedure, the light emitted by aliquot volumes of the suspension of the reconstituted bacteria, was recorded before and 5, 15 and 30 minutes after the addition of the sample solution. The test was run at least three times, taking as final value the mean of the values falling within the 20% deviation limits after the data reduction. The concentration causing a 50% reduction of the light emitted after 30 minutes of exposure, are reported as the toxicity values for the compound: 30 min-EC50 = 1.46 mg/l.

 

Maas-Diepeveen and van Leeuwen, 1986

Rel. 2; Rational for reliability: Study according to standard procedure. Basic data given.

The test with Photobacterium phosphoreum (Microtox test: Beckman, model 2055) and the calculation of the EC50 value were carried out in accordance with the procedure described in the Beckman Instruments Manual (1982). Tested 2,3-dichloronitrobenzene had a purity of > 98%. The stock solution of the compound was prepared in dimethylsulfoxide (DMSO; Merck, purity 99%). After an exposure period of 15 minutes an EC50 of 1.5 mg/l (95%C.L. 1.4-1.6) was found.

 

Tetrahymena pyriformis

Schultz, 1999

Rel. 2; Rational for reliability: Basic data given.

Population growth impairment testing with the common ciliate Tetrahymena pyriformis (strain GL-C) was conducted following the protocol described by Schultz (1997). This 40-h assay is static in design and uses population density quantitated spectrophotometrically at 540 nm as its end point. The test substance was tested in three replicates. Each test replicate consisted of six to eight different concentrations with duplicate flasks with each concentration. Only replicates with control absorbency values of > 0.6 but < 0.75 were used in the analysis. Two controls were used. In the test an IC50 of 233.5 mg/l was determined.

 

BUA report, 1990

In a test in fermentation tubes the effect of 1,2-dichloronitrobenzene to activated sludge bacteria from municipal sewage treatment plants was determined by measuring the inhibition of gas evolution under anaerobic conditions. A 24h-EC50 of 45 mg/L was determined.

Key value for chemical safety assessment