Calcium diformate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study. Suitability of the test substance: formic acid is almost exclusively present as formate anion in aqueous solution at neutral pH. Data on formic acid may therefore be used to assess formate salts.

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Unnamed

Year:

1992

Report date:

1992

Reference 2

Reference Type:

publication

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Formic acid

EC Number:

200-579-1

EC Name:

Formic acid

Cas Number:

64-18-6

Molecular formula:

CH2O2

IUPAC Name:

formic acid

Details on test material:

- Name of test material (as cited in study report): formic acid
- Analytical purity: 97.4%

Method

Target gene:

reversion in the His-operon

Species / strain

Species / strain / cell type:

other: S. typhimurium TA97, TA98, TA100, TA1535

Metabolic activation:

with and without

Metabolic activation system:

10% and 30% induced male Sprague Dawley rat liver S9 and induced male Syrian hamster liver S9

Test concentrations with justification for top dose:

0, 10, 33, 100, 333, 1000, 3333 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: water

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

water

Positive controls:

yes

Positive control substance:

other: Without metabolic activation: sodium azide (Ta1535 and TA100); 9-aminoacridine (TA97 and TA1537); 4-nitro-phenylenediamine (TA98 and TA1538). With metabolic activation: 2-aminoanthracene in all strains

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation); preincubation


DURATION
- Preincubation period: 20 min
- Exposure duration: 48 hours
- Expression time (cells in growth medium): 48 hours



SELECTION AGENT (mutation assays): histidine



NUMBER OF REPLICATIONS: chemicals were tested in triplicate; repeat experiments were conducted


NUMBER OF CELLS EVALUATED: his+ revertants


DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

Evaluation criteria:

A chemical was judged to be mutagenic if it produced a reproducible, dose-related response over the solvent control, under a single metabolic activation condition, in replicate trials. According to OECD TG 471.

Results and discussion

Test results

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: 1000 µg/plate (TA100)

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: other: Preincubation; S. typhimurium TA97, TA98, TA100, TA1535

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Detail data are included in the attached document.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

Sodium formate is considered to be negative. Reason: data on formic acid may be used to assess formate salts, because formic acid is almost exclusively present as formate anion in aqueous solution at neutral pH.

Executive summary:

Formic acid was tested in an in-vitro genotoxicity test using bacteria (TA97, TA98, TA100, and TA1535) with and without metabolic activation (supernatant from induced male rat and Syrian hamster liver) at concentrations of 0, 10, 33, 100, 333, 1000, and 3333 µg/plate in accordance with OECD Guideline No. 471. Solvent and positive controls were included and performed as expected. Tests were conducted in triplicate, and two independent experiments were conducted. The number of revertants was not increased in any strain with or without metabolic activation up to and including the top dose of formic acid. Bacteriotoxicity was seen at 1000 µg/plate and above (Zeiger, 1992).

 

Conclusions:

1) Formic acid lacked genotoxicity in a valid bacterial cell in-vitro test performed according to OECD Guideline No. 471.

2) Sodium formate is not mutagenic in bacteria. Reason: data on formic acid may be used to assess formate salts, because formic acid is almost exclusively present as formate anion in aqueous solution at neutral pH.