Triclocarban

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Justification for type of information:

Data is from secondary literature

Qualifier:

according to guideline

Guideline:

other: Refer below principle

Principles of method if other than guideline:

To evaluate the effect of test chemical on the domestic sewage by providing the exposure period of 16 days.

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

not specified

Test organisms (species):

other: domestic sewage

Details on inoculum:

Sludge source: Ocean County South Treatment Plant Test

Test type:

other: Anaerobic Digester Inhibition Test

Water media type:

not specified

Total exposure duration:

16 d

Test temperature:

32 degree C

pH:

7.4

Details on test conditions:

Total alkalinity: 2,600 mg/l CaCO3

Reference substance (positive control):

not specified

Key result

Duration:

16 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of anaerobic gas production

Remarks on result:

other: Other details not known

Validity criteria fulfilled:

not specified

Conclusions:

After the exposure period of 16 days, effect of test chemical on the domestic sewage were determine. The NOEC was determine to be at 100 mg/l.

Executive summary:

To evaluate the effect of test chemical on the domestic sewage by providing the exposure period of 16 days. Domestic sewage was obtain ocean County South Treatment Plant Test. Anaerobic Digester Inhibition test was performed. After the exposure period of 16 days, effect of test chemical on the domestic sewage were determine. The NOEC was determine to be at 100 mg/l.

Description of key information

Toxicity to microorganisms:

The MIC values were determined by the microbroth dilution assay according to the National Committee for Clinical Laboratory Standards methods for antimicrobial susceptibility tests for aerobically growing bacteria (Approved Standard M7-A2, NCCLS, Villanova, PA, 1990).

Approximately 6.5 3 108 cells of strain RN4220 (25) were plated on to brain-heart infusion agar medium (Becton-Dickinson) containing 0.5 mg/ml test material. The plates were incubated at 37 °C with periodic monitoring. After 48 h, resistant clones were picked and their phenotype confirmed by regrowth on the original selective concentration of test material.

Three strains of Staphylococcus aureus namely RN4220 (wild-type) , RN4220/pTri-1 , GR664 (fabIG23S) and three starins of E.coli

W3110 (wild-type) , W3110/pFabI , RJH108 (fabIG93V) . The wild-type FabI proteins from either S. aureus or E. coli were expressed using plasmids pTri-1 or pFabI, respectively, to determine if resistance was conferred by the presence of multiple copies of the fabI genes.

The minimum ihhibition concentration (MIC) was observed in the range of 0.25 to 2 mg/l in case of Staphylococcus aureus and for E.Coli MIC was observed in concentration range of 0.5 - 35 mg/l.

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

100 mg/L

Additional information

Toxicity to microorganisms:

The MIC values were determined by the microbroth dilution assay according to the National Committee for Clinical Laboratory Standards methods for antimicrobial susceptibility tests for aerobically growing bacteria (Approved Standard M7-A2, NCCLS, Villanova, PA, 1990).

Approximately 6.5 3 108 cells of strain RN4220 (25) were plated on to brain-heart infusion agar medium (Becton-Dickinson) containing 0.5 mg/ml test material. The plates were incubated at 37 °C with periodic monitoring. After 48 h, resistant clones were picked and their phenotype confirmed by regrowth on the original selective concentration of test material.

Three strains of Staphylococcus aureus namely RN4220 (wild-type) , RN4220/pTri-1 , GR664 (fabIG23S) and three starins of E.coli

W3110 (wild-type) , W3110/pFabI , RJH108 (fabIG93V) . The wild-type FabI proteins from either S. aureus or E. coli were expressed using plasmids pTri-1 or pFabI, respectively, to determine if resistance was conferred by the presence of multiple copies of the fabI genes.

The minimum ihhibition concentration (MIC) was observed in the range of 0.25 to 2 mg/l in case of Staphylococcus aureus and for E.Coli MIC was observed in concentration range of 0.5 - 35 mg/l.

In another secondary data for test chemical the effect of test chemical on the domestic sewage by providing the exposure period of 16 days. Domestic sewage was obtain ocean County South Treatment Plant Test. Anaerobic Digester Inhibition test was performed. After the exposure period of 16 days, effect of test chemical on the domestic sewage were determine. The NOEC was determine to be at 100 mg/l.