Dibutyl phosphonate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23 June to August, 1977

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1977

Report date:

1977

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Dibutyl phosphonate

EC Number:

217-316-1

EC Name:

Dibutyl phosphonate

Cas Number:

1809-19-4

Molecular formula:

C8H19O3P

IUPAC Name:

dibutyl phosphonate

Test material form:

liquid

Method

Target gene:

No data

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Details on mammalian cell type (if applicable):

Salmonella typhimurium

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 1538

Details on mammalian cell type (if applicable):

Salmonella typhimurium

Species / strain 3

Species / strain / cell type:

Saccharomyces cerevisiae

Details on mammalian cell type (if applicable):

Strain: D4

Metabolic activation:

with and without

Metabolic activation system:

S9

Test concentrations with justification for top dose:

0.001, 0.01, 0.1, 1.0 and 5.0 µL

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: deionized water or DMSO

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: methylnitrosoguanidine

Remarks:

without S9

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

2-nitrofluorene

other:

Remarks:

without S9

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: quinacrine mustard

Remarks:

without S9

Controls 4

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: 2-Antramine

Remarks:

with S9

Controls 5

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

2-acetylaminofluorene

Remarks:

with S9

Controls 6

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 8-Aminoquinoline

Remarks:

with S9

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar

Approximately 10^6 cells from overnight culture of each indicator strain were added to separate test tubes containing 2.0 mL of molten agar supplemented with biotin and trace of histidine. For activation test, at least four dose levels of test compound were added to the contents of the appropriate tubes and poured over the surface of selection of four different concentrations of the test chemical were added to the contents of the appropriate tubes with cells.
Just prior to pouring, an aliquot of reaction mixture (0.5 mL containing the 9000 x g liver homogenate) was added to each of the activation overlay tubes, which were then mixed, and the contents poured over the sacrifice of a minimal agar plate and allowed to solidify. The plates were incubated for 48 hours at 37 °C, and scored for the number of colonies growing on each plate. The concentrations of all chemicals are given in the result section. Positive and solvent controls using both directly active positive chemicals and those that require metabolic activation were run with each assay.

STUDY DESIGN
The compound was tested over a series of concentrations such that chemically-induced physiological effects at the high dose level. The low dose in all cases was below a concentration that demonstrated any toxic effect. The dose range employed for the evaluation of this compound was from 0.001 µL to 5 µL per plate. The compound was toxic to all the strains at 5 µL per plate.

Statistics:

The number of colonies on each plate were counted and recorded on printed form. These raw data analyzed in a computer program and reported on a printout. The results are presented as revertant per plate for each indicator strain employed in the assay. The positive and the solvent controls are provided as reference points. Other relevant data are provided on the computer printout.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Species / strain:

Saccharomyces cerevisiae

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Toxicity test:
- The dose range employed for the evaluation of this of this compound was from 0.001 µL to 5 µL per plate. The compound was toxic to all the strains at 5µL per plate.
Nonactivation test results:
- The results of the tests conducted on the compound in the absence of a metabolic system were all negative.
Activation test results:
- The results of the tests conducted on the compound in the presence of the rat liver activation system were all negative.

Remarks on result:

other: all strains/cell types tested

Applicant's summary and conclusion

Conclusions:

Negative with and without metabolic activation

Executive summary:

The potential for the substance to induce an increase in reverse mutatitions in bacterial cells was evaluated in an AMES test, equivalent to the OECD Guideline 471. The objective of this test was to evaluate the compound for genetic activity in microbial assays of Salmonella typhimurium TA 1535, TA 1537, TA1538, TA 98 and TA 100, as well as Saccharomyces cerevisiae strain D4, with and without the addition of mammalian metabolic activation preparation, at test concentrations of 0.001, 0.01, 0.1, 1.0 and 5.0 µL.

The compound was toxic to all the strains at 5 µL per plate. The test item did not demonstrate increased mutagenic activity in any of the assays conducted in this evaluation and was considered not mutagenic under these test conditions.