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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1976
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study

Data source

Reference
Reference Type:
publication
Title:
Light-induced genetic toxicity of thimerosal and benzalkonium chloride in commercial contact lens solutions
Author:
Thomas J. Lovely, David E. Levin and Ed Klekowski
Year:
1980
Bibliographic source:
Mutation Research, 101 (1982) 11-18 - Elsevier Biomedical Press
Report Date:
1980

Materials and methods

Test guidelineopen allclose all
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Version / remarks:
plate incorporation asay
Qualifier:
according to
Guideline:
other:
Version / remarks:
Rosenkranz E coli assay
Principles of method if other than guideline:
publication of (Ames 1975) served as basis for OECD guideline 471 : Ames, B.N., McCann, J. and Yamasaki, E. (1975). Methods for Detecting Carcinogens and Mutagens with the Salmonella/Mammalian-Microsome Mutagenicity Test. Mutation Res., 31, 347-364.
Secondary assay on E. Coli: Rosenkranz, H S, B Gutter and W T Speck, Microbial assay procedures Experience with two systems, in F J De Serres et al (Eds), In Vitro Metabolic Activation in Mutagene~ls Testing, Elsevier, Amsterdam, 1976, pp 337-361
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
additive
Details on test material:
obtained from Sigma Chemical Co. Benzalkonlum chloride is a mixture of alkyldlmethylbenzylammonium chlorides.

Method

Target gene:
Histidine gene
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1538
Species / strain / cell type:
S. typhimurium TA 98
Species / strain / cell type:
S. typhimurium TA 1537
Species / strain / cell type:
S. typhimurium TA 100
Species / strain / cell type:
E. coli, other: strain W3110 (polA +) and the mutant strain p3478 (polA-)
Additional strain / cell type characteristics:
DNA polymerase A deficient
Remarks:
Increased sensitivity to UV light in mutants lacking the enzyme. Polymerase A strains have a reduced capacity to repair damaged DNA.
Metabolic activation:
with and without
Metabolic activation system:
S9
Test concentrations with justification for top dose:
Standard plate Incorporation assays were done with volumes of test solution ranging between 0.1 and 0.5 ml, with 0.1 ml of culture and 0.5 ml of $9 mix (if indicated) in 2.0 ml of top agar
Benzalkonium chloride doses 0.01%, 0.02%, 0.1%
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Remarks:
disodium edetate
True negative controls:
yes
Remarks:
chloramphenicol
Positive controls:
yes
Positive control substance:
9-aminoacridine
2-nitrofluorene
benzo(a)pyrene
methylmethanesulfonate
other: daunomycin for TA98,
Details on test system and experimental conditions:
Dark/ light: After incubation at 37°C for 48 h either in the dark, or under a combination of fluorescent(15 W) and incandescent (40W) lights (General Electric Cool White, 350 750 nm emission), at 24 inches, the plates were scored for His + revertant colonies. The fluence rate (556 nm) at this distance was 635 ~W/cm ~.
Evaluation criteria:
mutagenicity

Results and discussion

Test resultsopen allclose all
Key result
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1538
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium, other: TA1536
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
E. coli, other: strain W3110 (polA +)
Metabolic activation:
not specified
Genotoxicity:
ambiguous
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
E. coli, other: strain mutant p3478 (polA-)
Remarks:
increased sensitivity to UV light and reduced capacity to repair damaged DNA.
Metabolic activation:
not specified
Genotoxicity:
ambiguous
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
not determinable because of methodological limitations
Remarks:
no dose/response relationship, no replicate nor statistical analysis

Applicant's summary and conclusion

Conclusions:
Non mutagenic in the Ames test (protocole comparable to OECD 471 assay).
Executive summary:

Non mutagenic in the Ames test (protocole comparable to OECD 471 assay).