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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: GLp Guideline study in accordance with OECD TG 471. However only 4 strains testedoever

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report date:
1988

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
4 strains only
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
Ethyl chloroformate
EC Number:
208-778-5
EC Name:
Ethyl chloroformate
Cas Number:
541-41-3
Molecular formula:
C3H5ClO2
IUPAC Name:
ethyl chlorocarbonate
Details on test material:

- Name of test material (as cited in study report): c hloroformic acid ethyl ester
- Analytical purity: 98.0%.
- Physical state: liquid

Method

Target gene:
Salmonella Typhimurium: (his-)
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
S-9 mix including Aroclor induced male Sprague-Dawley rat liver 9000 g supernatant
Test concentrations with justification for top dose:
0.0005 - 5.0 microliters/plate (TA1535);
0.0005 - 0.4 microliters/plate (TA98, TA100, TA1537)
Vehicle / solvent:
- Vehicle(s)/solvent used:ethanol
- Justification for choice of solvent/vehicle: soulability,
Controlsopen allclose all
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Remarks:
ethanol
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene (2-AA)
Remarks:
with metabolic activation TA 1535, TA 1537, TA 98 and TA 100
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Remarks:
ethanol
Positive controls:
yes
Positive control substance:
other: N- methyl - N '- nitro - N - nitroso - guanidine ( MNNG)
Remarks:
TA 1535; TA 100 without metabolic activation
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Remarks:
Ethanol
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
TA 1537 without metabolic activation
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Remarks:
Ethanol
Positive controls:
yes
Positive control substance:
other: 4-nitro-o-phenylendiamine
Remarks:
TA 98 without metabolic activation
Details on test system and experimental conditions:
METHOD OF APPLICATION: preincubation
DURATION
- Preincubation period: 20 min
- Exposure duration: 48 hours
- Expression time (cells in growth medium): 48 hours

SELECTION AGENT (mutation assays): histidine

NUMBER OF REPLICATIONS: 3

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth


Evaluation criteria:
A substance was considered mutagenic if it caused a doubling in the spontaneous mutation rate, and the effect was dose-dependent and repro-
ducible.
Statistics:
no data

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:
cytotoxicity
Remarks:
> = 0.015 microliters/plate (without S-9 mix); > = 0.2 microliters/plate (with S-9 mix)
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

There was no mutagenic effect of test material in the presence or absence of S-9. The test material was completely soluble in ethanol.

In the absence of S-9, the average numbers of mutants in controls in strains TA98, TA100, TA1535 (all experiments), and TA1537 were 23, 149, 16-18, and 10, respectively. The average numbers of mutants in treated strains TA98, TA100, TA1535 and TA1537 ranged from 23-27, 154-164, 0-18, and 3-9, respectively.

In the presence of S-9, the average numbers of mutants in controls in strains TA98, TA100, TA1535 (all experiments) and TA1537 were 33, 134, 17-25, and 10, respectively. The average numbers of mutants in treated strains TA98, TA100, TA1535, and TA1537 with S-9 ranged from 29-36, 134-137, 0-23, and 6-11, respectively.


The positive control material DIMCA caused a dose-dependent increase in mutants in strain TA1535 in the absence or presence of S-9.
  With strain TA100, a weakly positive effect of DIMCA was found, with a maximum increase in the number of mutants at 0.5 microliters/plate of a factor of 2.3 (without S-9 mix) or 2.0 (with S-9 mix).  All other positive controls induced at least a 4-fold increase in mutants.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

Ethylchloroformiate was neagtive in an OECD TG 471 preincubation study.