1,2,4-trichlorobenzene

Toxicity to soil microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil microorganisms

Type of information:

other: EU Risk Assessment

Adequacy of study:

other information

Reliability:

other: EU Risk Assessment

Rationale for reliability incl. deficiencies:

other: No reliability is given as this is a summary entry for the EU RAR.

Principles of method if other than guideline:

EU Risk Assessment

GLP compliance:

not specified

EU Risk Assessment (2003):

1,2,4-TCB was toxic to soil microbiota as CO2 development was reduced at increasing concentrations. At 50µg/g sandy soil, the total CO2 evolution was depressed to approximately 50% of the normal and the turnover optimum measured as percent 1,2,4-TCB degradation was

between 10 and 25µg/g during a 24-hour study period (Marinucci and Bartha, 1979).

 

The toxicity of 1,2,4-TCB on terrestrial microorganisms was studied on a terrestrial bacterium by insertion of lux genes into the genome of Pseudominas fluorescens. The bioluminiscence was determined after 20 minutes of exposure to mono-, di-, tri-, tetra-, penta- and hexachlorobenzene. The toxicity increased with the chlorination. For 1,2,4-TCB, the EC50 was 18.3 mg/l (Boyd et al., 1998). The test was performed with a soil bacteria, but in a short-term test in an aqueous solution.

Executive summary:

EU Risk Assessment, 2003:

 

1,2,4-TCB was toxic to soil microbiota as CO2 development was reduced at increasing concentrations. At 50µg/g sandy soil, the total CO₂ evolution was depressed to approximately 50% of the normal and the turnover optimum measured as percent 1,2,4-TCB degradation was between 10 and 25µg/g during a 24 h study period (Marinucci and Bartha, 1979).

The toxicity of 1,2,4-TCB on terrestrial microorganisms was studied on a terrestrial bacterium by insertion of lux genes into the genome of Pseudominas fluorescens. The bioluminiscence was determined after 20 minutes of exposure to mono-, di-, tri-, tetra-, penta- and hexachlorobenzene. The toxicity increased with the chlorination. For 1,2,4-TCB, the EC₅₀ was 18.3 mg/l (Boyd et al., 1998).

The test was performed with a soil bacteria, but in a short-term test in an aqueous solution.

Description of key information

For transported isolated intermediates according to REACh, Article 18, 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".

 

EU Risk Assessment, 2003:

1,2,4-TCB was toxic to soil microbiota as CO2 development was reduced at increasing concentrations. At 50µg/g sandy soil, the total CO2 evolution was depressed to approximately 50% of the normal and the turnover optimum measured as percent 1,2,4-TCB degradation was between 10 and 25µg/g during a 24 h study period (Marinucci and Bartha, 1979).

The toxicity of 1,2,4-TCB on terrestrial microorganisms was studied on a terrestrial bacterium by insertion of lux genes into the genome of Pseudominas fluorescens. The bioluminiscence was determined after 20 minutes of exposure to mono-, di-, tri-, tetra-, penta- and hexachlorobenzene. The toxicity increased with the chlorination. For 1,2,4-TCB, the EC50 was 18.3 mg/l (Boyd et al., 1998).

The test was performed with a soil bacteria, but in a short-term test in an aqueous solution.