Benzoic acid

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro cytogenicity / micronucleus study

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Limited report, non-GLP, the omission of information on status of cell division does not lower the reliability

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1999

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

other: OECD 487

Deviations:

yes

Remarks:

no method included to check cell division status

Principles of method if other than guideline:

Mouse lymphoma L5178Y cells were used in this study. Three types of treatment were carried out parallel: two treatments without metabolic activation with or without a recovery period after 24 h continuous treatment and one treatment with metabolic activation by S9 mix. The concentrations of the test substance were 1000, 500, 250 μg/mL in the three type of treatment. Mitomycin C was used as a positive control in the absence of S9 mix and cyclophosphamide was used as a positive control in the presence of S9 mix.

GLP compliance:

not specified

Type of assay:

in vitro mammalian cell micronucleus test

Test material

Test material information

Constituent 1

Reference substance name:

Benzoic acid

EC Number:

200-618-2

EC Name:

Benzoic acid

Cas Number:

65-85-0

Molecular formula:

C7H6O2

IUPAC Name:

benzoic acid

Details on test material:

Batch No.: not specifiedPurity: > 99%

Method

Target gene:

None stated

Species / strain

Species / strain / cell type:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

1000, 500, 250 μg/mL (cytotoxicity at 200 ug/mL)

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO- Justification for choice of solvent/vehicle:

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

no

True negative controls:

no

Positive controls:

yes

Positive control substance:

mitomycin C

Remarks:

In the absence of S9 mix

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

no

True negative controls:

no

Positive controls:

yes

Positive control substance:

cyclophosphamide

Remarks:

In the presence of S9 mix

Details on test system and experimental conditions:

METHOD OF APPLICATION: in mediumDURATION- Preincubation period: 10-12 h- Exposure duration: 24 h without S9 mix, 4 h with S9 mix- Expression time (cells in growth medium): 0 or 20 hours without S9 mix, 24 hours with S9 mix- Selection time (if incubation with a selection agent):- Fixation time (start of exposure up to fixation or harvest of cells): 10 minSELECTION AGENT (mutation assays):SPINDLE INHIBITOR (cytogenetic assays): ethanol/acetic acidSTAIN (for cytogenetic assays): with 2% Giemsa water solutionNUMBER OF REPLICATIONS: 2NUMBER OF CELLS EVALUATED: 1000DETERMINATION OF CYTOTOXICITY- Method: colometric method

Evaluation criteria:

The criteria for determining a positive result were a concentration-related increased in the number of micronucleated cells and a statistically significant increase over the spontaneous level in at least one treatment schedule. Cells with more than 5 micronuclei were excluded from the evaluation to prevent nuclear fragmentation prvent.

Statistics:

The statistical significance of differences between groups was determined using the X2 test.

Results and discussion

Test results

Species / strain:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

None stated

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):negativeThe test substance gave negative responses both with or without metabolic activation.

Executive summary:

Mouse lymphoma L5178Y cells were used in this study. Three types of treatment were carried out parallel: two treatments without metabolic activation with or without a recovery period after 24 h continuous treatment and one treatment with metabolic activation by S9 mix. The concentrations of the test substance were 1000, 500, 250 μg/mL in the three type of treatment. Mitomycin C was used as a positive control in the absence of S9 mix and cyclophosphamide was used as a positive control in the presence of S9 mix.

The test substance gave unequivocal negative responses both with or without metabolic activation or cytotoxicity.