Phthalic anhydride

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: guideline study

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1996

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Principles of method if other than guideline:

Preincubation method according to OECD TG 471.

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Phthalic anhydride

EC Number:

201-607-5

EC Name:

Phthalic anhydride

Cas Number:

85-44-9

Molecular formula:

C8H4O3

IUPAC Name:

1,3-dihydro-2-benzofuran-1,3-dione

Details on test material:

purity: 99.5 %

Method

Target gene:

No data

Species / strain

Species / strain / cell type:

other: Salmonella typhimurium TA100, TA 102, TA1535, TA98, TA1537, E. coli WP2uvrA

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

Preparation of S9 fraction:
Male Sprague-Dawley rats were used for the preparation of liver fractions. Sodium phenobarbital and 5,6-benzoflavone were used as an inducer of the rat metabolic activation system. Sodium phenobarbital was injected intraperitoneally into the rats 4 days before killing and 1, 2 and 3 days before killing 5,6 benzoflavone was injected intraperitoneally. From these rats liver S9 fraction was prepared according to Ames et al. (1975) Methods for detecting carcinogens and mutagens in the Salmonella /mammalian microsome mutagenicity test. Mutat. Res. 31, 347-364. S9 was dispensed into freezing ampules and stored at -80° C. Once the stock S9 had been thawed, remained S9 was not reused.

Test concentrations with justification for top dose:

0, 20, 39, 78, 156, 313, 625, 1250, 2500, 5000 ug/plate dissolved in DMSO

Vehicle / solvent:

solvent: DMSO

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: see 'Any other information on materials and methods incl. tables'

Details on test system and experimental conditions:

Ames test

Evaluation criteria:

The chemicals are considered to be mutagenic when dose-related increase in revertant colony count is observed and the number of revertant colonies per plate with the test substance is more than twice that of the negative control (solvent control) and when a reproducibility of the test result is observed.

Results and discussion

Test results

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:

other: 2500 ug/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: negative

Any other information on results incl. tables

Phthalic anhydride was tested up to 5000 µg/plate. Cytotoxic effects were observed in the absence or in the presence of metabolic activator at concentrations equal or higher than 5000 or 313 µg/plate, respectively. Phthalic anhydride did not induce mutations in the bacterial mutation test, neither in the absence, nor in the presence of metabolic activator.

Positive and negative controls gave the expected values.

Applicant's summary and conclusion

Executive summary:

Ames test preincubation method according to OECD TG 471.

Result: negative, phthalic anhydride did not induce mutations in the bacterial mutation test, neither in the absence or presence of metabolic activator.