2-chloro-1,1-diethoxyethane

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: OECD Guideline Study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Ethane, 2-Chloro-1,1-Dimethoxy-

IUPAC Name:

Ethane, 2-Chloro-1,1-Dimethoxy-

Constituent 2

Reference substance name:

97-97-02

IUPAC Name:

97-97-02

Constituent 3

Reference substance name:

2-chloro-1,1-dimethoxyethane

EC Number:

202-624-0

EC Name:

2-chloro-1,1-dimethoxyethane

Cas Number:

97-97-2

Molecular formula:

C4H9ClO2

IUPAC Name:

2-chloro-1,1-dimethoxyethane

Test material form:

other: liquid

Details on test material:

- Name: Chloroacetaldehyde dimethylacetal
- Physical state: colourless liquid

Method

Species / strain

Species / strain / cell type:

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

Metabolic activation:

with and without

Test concentrations with justification for top dose:

without metabolic activation: 2.5, 5.0, 25.0, 50.0, 250.0, 500.0, 2500.0, 5000.0 µg/plate
with metabolic activation: 50.0, 250.0, 500.0, 2500.0, 5000.0 µg/plate

Controls

Controls 1

Untreated negative controls:

yes

Positive controls:

yes

Positive control substance:

other:

Remarks:

Natrium Acid for TA100, TA1535 without metabolic activation

Controls 2

Untreated negative controls:

yes

Positive controls:

yes

Positive control substance:

2-nitrofluorene

Remarks:

TA98 without metabolic activation

Controls 3

Untreated negative controls:

yes

Positive controls:

yes

Positive control substance:

other: DMSO

Remarks:

TA1537 without metabolic activation

Controls 4

Untreated negative controls:

yes

Positive controls:

yes

Positive control substance:

other: DMSO

Remarks:

TA98, TA100, TA1535, TA1537 with metabolic activation

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

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):
positive

Because of the test results the test substance Chloroacetaldehyde dimethylacetal shows mutagenic properties in strains TA98, TA100 and TA1535.

Executive summary:

Chloroacetaldehyde dimethylacetal was tested on its potential to dissolve gene mutation in the genomeof the Salmonella typhimurium TA98, TA100, TA1535 and TA1537 strains. Two independent tests were carried out independently with and without metabolic activation. The substance was tested in following concentrations:

Without metabolic activation: 2.5, 5.0, 25.0, 50.0, 250.0, 500.0, 2500.0, 5000.0 µg/plate

With metabolic activation: 50.0, 250.0, 500.0, 2500.0, 5000.0 µg/plate

Distilled water was chosen as solvent for the test substance because of its good solubility character. Precipitations caused of the test substance were noticed neither at the single dilutions nor in the agar. Every concentration including the controls was tested three times. Apart from TA98 all strains showed normal background growth in presence of the test solution at all concentrations. Strain TA98 showed lower background growth as well as a clearly reduced number of revertants at test concentrations 5000, 2500 and 500 µg/ plate in experiment I without metabolic activation. In experiment II the background growth was considerably declined as in controls at concentrations of 5000 and 2500 µg. These toxicological effects didn’t appear at metabolic activation.

Compared to the negative controls with concentrations of 5000 and 2500 µg/plate a significant and reproducible increase of the revertant numbers was noticed in test strain TA100. The revertant number of strain TA100 with metabolic activation was increased in experiment I (5000µg/plate; mutation factor 4.6), in experiment II this effect was observed as well at concentration 2500 µg/plate. At concentrations of 5000 µg and 2500 µg/plate mutation factors of 5.6 and 3.5 were determined here. In both experiments a mutagenic effect at test strain TA100 was proved through the test substance. The considerable mutation factor for the mutagenic effect of 2 was clearly exceeded. Reproducible dose dependent mutagenic effects were observed at concentrations of 5000 and 2500 µg/plate in experiment I (mutation factors 3.1 and 2.4) and experiment II (mutation factors 2.8 and 1.9) in presence of the liver microsomal fractionin test strain TA1535 and TA100 as well as a bacterium with a mutation regarding base pairing. At test strain TA1535 the increase of the revertant numbers was slightly lower without metabolic activation and a concentration of 5000 µg/plate, but it can be supposed of a mutagenic effect because the results were reproducible (mutation factors 1.9 and 1.8). Slightly increased revertant numbers were observed in both experiments in TA98 at the highest test concentration with metabolic activation (mutation factors 2.1 and 1.8). No mutagenic properties of the test substance in all concentrations were shown in TA1537. The recommended area of the spontaneous reversion rates (3.4) referred to the negative controls without metabolic activation was never left at the mean rate of 3 plates. Suitable reference substances showed clear increases of the revertant numbers at the test strains and confirmed the enzymatic activity of the liver microsomal fraction. Because of the test results the test substance Chloroacetaldehyde dimethylacetal shows mutagenic properties in strains TA98, TA100 and TA1535.