Hydroquinone

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:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study is comparable to guideline study with the following acceptable restrictions: other positive control substance used for TA98; only 4 bacteria strains tested, no strain used sensitive to oxidative damage; sufficient documentation of testing procedure and test results; study acceptable as key study for mutagenicity testing in strains TA98, TA100, TA1535, and TA1537

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference 1

Reference Type:

review article or handbook

Title:

Salmonella mutagenicity test results for 250 chemicals.

Author:

Haworth S, Lawlor T, Mortelmans K, Speck W, Zeiger E

Year:

1983

Bibliographic source:

Environ Mutagen 5 (Suppl 1), 1 - 142

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

(other positive control for TA98; only 4 bacteria strains tested, no strain used sensitive to oxidative damage)

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Hydroquinone

EC Number:

204-617-8

EC Name:

Hydroquinone

Cas Number:

123-31-9

Molecular formula:

C6H6O2

IUPAC Name:

hydroquinone

Details on test material:

- Name of test material (as cited in study report): hydroquinone
- Analytical purity: not specified (label purity: " purified ")
- Stability under test conditions: test solutions were prepared immediately before use

Method

Species / strain

Species / strain / cell type:

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

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254-induced S9 from male Syrian hamster liver or male Sprague-Dawley rat liver

Test concentrations with justification for top dose:

0, 10, 33, 100, 333, 666 µg/plate

Vehicle / solvent:

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

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: without S9: 4-nitro-o-phenylenediamine with TA98, sodium azide with TA100 and TA1535, 9-aminoacridine with TA1537; with S9: 2-aminoanthracene with 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 h

SELECTION AGENT (mutation assays): histidine

NUMBER OF REPLICATIONS: 3 plates/assay, and 2 assays

DETERMINATION OF CYTOTOXICITY
- Method: viability or reduced number of revertant colonies per plate

Evaluation criteria:

Positive response indicated by reproducible, dose-related increase, whether it would be two-fold over background or not

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

Remarks:

revertant rates similar to controls at all tested concentrations

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

in all strains without metabolic activation from 333 µg/plate up

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

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):
negative

There was no indication of a mutagenic activity in S. typhimurium strains TA98, TA100, TA1535, and TA1537.

Executive summary:

Hydroquinone (10 - 666 µg/plate) was tested in a Salmonella typhimurium reverse mutation assay with strains TA98, TA100, TA1535, and TA1537 applying a preincubation test protocol comparable to OECD Guideline 471. There was no indication of mutagenic activity up to cytotoxic concentrations (333 and 666 µg/plate) both in the absence and presence of metabolic activation (S9 mix from Aroclor 1254 -induced hamster or rat liver).