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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in mammalian cells
Remarks:
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1990
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Well documented, according to accepted guidelines

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1990
Report Date:
1990

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)
Deviations:
no
GLP compliance:
yes
Type of assay:
mammalian cell gene mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Isopropanol
- Physical state: Clear, colorless liquid
- Analytical purity: 99.8%
- Lot/batch No.: TS-1621101

Method

Species / strain
Species / strain / cell type:
Chinese hamster Ovary (CHO)
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254-induced rat liver microsomes (S9)
Test concentrations with justification for top dose:
Range-finding (cytotoxicity) assay: 0.0098, 0.0195, 0.0391, 0.0781, 0.156, 0.313, 0.625, 1.25, 2.5, or 5.0 mg/mL
Mutation assay (- & + S9): 0.5, 1.0, 2.0, 3.0, 4.0, or 5.0 mg/mL (Trial 1)
Mutation assay (- S9): 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, or 5.0 mg/mL (Trial 2)
Mutation assay (+ S9): 0.5, 1.0, 2.0, 3.0, 3.5, 4.0, 4.5, or 5.0 mg/mL (Trial 2)
Mutation assay (- S9): 1.0, 2.0, 3.0, 4.0, 4.5, or 5.0 mg/mL (Trial 3)
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: sterile, deionized water
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Remarks:
sterile, deionized water
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 5-bromo-2-deoxyuridine (-S9) and 3-methylcholanthrene (+S9)
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium

DURATION
- Exposure duration: 4 hours at 37 ºC
- Expression time (cells in growth medium): 7 days
- Selection time (if incubation with a selection agent): 7 to 10 days at 37 ºC

NUMBER OF REPLICATIONS: 3 (-S9) or 2 (+S9) independent experiments.
Evaluation criteria:
(a) A dose- or toxicity-related increase in mutant frequency must be observed for at least 3 doses.
(b) A mutagenic dose-response in one assay should be confirmed in a second mutation assay.
(c) If an increase in mutant frequency is observed in one trial for a treated culture near the highest testable toxicity and the number of mutant colonies is more than twice the value needed to indicate a significant response, the test article generally will be considered to be mutagenic.
(d) Applied concentration or toxicity (% survival) can be used to establish whether the mutagenic activity is related to an increase in effective treatment.
(e) Treatments that reduce relative clonal survival to less than 5% may be included in the assay but will not be used as sufficient evidence of mutagenicity as it relates to risk assessment.
Statistics:
Not performed (colonies are counted)

Results and discussion

Test results
Species / strain:
Chinese hamster Ovary (CHO)
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
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 with metabolic activation
negative without metabolic activation