Registration Dossier

Diss Factsheets

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)

Data source

Referenceopen allclose all

Reference Type:
review article or handbook
Title:
Dose doc no. : T230
Author:
RSC Publishing
Year:
2011
Bibliographic source:
Dictionary of Substances and their effects (DOSE):- Mutat. Res. 1983, 117(1-2), 21-30; Mutagenicity of dichloroacetylene and its degradation products trichloroacetyl chloride, trichloroacryloyl chloride and hexachlorobutadiene.; Reichert, D. et al
Reference Type:
other: Authoritative data base
Title:
HSDB Number : 6321
Year:
2011
Bibliographic source:
HSDB (Hazardous Substances Data Bank); Reichert D et al; Mutat Res 117 (1-2): 21-30 (1983)

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other:
Principles of method if other than guideline:
modified Ames mutagenicity assay in vitro with the histidine-auxotrophic strains
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
Trichloroacetyl chloride
EC Number:
200-926-7
EC Name:
Trichloroacetyl chloride
Cas Number:
76-02-8
Molecular formula:
C2Cl4O
IUPAC Name:
trichloroacetyl chloride

Method

Species / strain
Species / strain / cell type:
S. typhimurium, other: TA98, TA100
Details on mammalian cell type (if applicable):
histidine-auxotrophic strains
Metabolic activation:
with and without
Metabolic activation system:
rat liver homogenate (S9 mix)
Details on test system and experimental conditions:
The bacteria were grown overnight in Oxoid nutrient broth, washed and resuspended in 0.1 M phosphate buffer (pH 7.4) to half the original density. The cell suspension, containing about 1 x 10 9 cells/ml, was divided into aliquots of 1.5 ml in centrifuge tubes; then 0.5 ml of either 0.1 M phosphate buffer (pH 7.4) or S9 mix and the test compound (diluted in 10/~1 acetonitrile) was added. The tubes were tightly closed with screw caps and incubated for 90 min at 37°C in a shaking water-bath. The treatment was terminated by centrifugation and resuspension in 1.1 ml fresh buffer. Aliquots of 0.5 ml cell suspension were then added to molten top agar (2 ml each) and duplicate petri dishes containing Vogel-Bonner medium E (= minimal agar) overlaid. For the determination of survival rates, an aliquot of the cell suspension was diluted by a factor of 10(4) in 0.9% NaCI; 10 µl of this dilution was added to 2 ml top agar, containing a 100-fold higher concentration of histidine (5 mM) than that in top agar for counting revertant colonies. Colonies of revertants and survivors were counted after 48 h of incubation at 37°C; the sensitivities of the tester strains were routinely checked with 2- aminoanthracene as a standard mutagen in the presence of S9 mix and with 4-nitro-o-phenylenediamine (TA98) or sodium azide (TA100) in its absence.

Results and discussion

Test results
Species / strain:
S. typhimurium, other: TA98, TA100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Remarks on result:
other: other:
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

The genotoxicity study of trichloroacetyl chloride on Salmonella typhimurium TA98, TA100 with and without metabolic activation gave negative result.
Executive summary:

Dichloroacetylene (DCA) is a highly reactive compound that decomposes rapidly in contact with air into a series of chlorinated aliphatic hydrocarbons (e.g., phosgene, trichloroacetyl chloride, trichloroacryloyl chloride and hexachlorobutadiene). Experiments were performed to compare the mutagenic properties of DCA and its degradation products on the histidine-dependent tester strains TA98 and TA100 of Salmonella typhimurium. In these experiments, DCA vapour was streamed under analytical control through the bacterial suspensions. DCA is soluble in aqueous solution and was stable under the experimental steady-state conditions of the bacterial exposure. There is a linear correlation between the supply of DCA vapour and solubilized DCA in the range of 1000 and 16000 ppm. Mutagenic response was observed with strain TA100 if the bacteria were suspended in Oxoid medium. No mutagenicity could be detected with strain TA98. DCA mixtures with acetylene, as used as stabilizer for animal experiments, were not mutagenic in either bacterial strain, irrespective of the presence or absence of S9 mix in the cell suspension. One of the degradation products of DCA, trichloroacryloyl chloride, showed pronounced mutagenic properties with and without drug-metabolizing enzymes. Other degradation products of DCA, such as trichloroacetyl chloride and hexachlorobutadiene, were not mutagenic, either in the presence or absence of liver homogenate.

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