Trichloroacetyl chloride

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

significant methodological deficiencies

Remarks:

Non standard method of application which makes uncertain the concentration tested

Data source

Reference

Reference Type:

publication

Title:

Dichloroacetic acid and related compounds: induction of prophage in E. coli and mutagenicity and mutation spectra in Salmonella TA100

Author:

David M.DeMarini, Erica Perry and Melissa L.Shelton

Year:

1994

Bibliographic source:

Mutagenesis, vol. 9 no. 5, pages 429-437

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

only TA100 tested, vaporization technique, few information available

Principles of method if other than guideline:

The mutagenicity of Trichloroacetyl chloride (TCAC) (volatilde compound) in strain TA100 of Salmonella was evaluated using the vaporization technique (Hughues et al., 1987).

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

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

Test material form:

liquid

Details on test material:

Purity: 99%
No other information was available.

Specific details on test material used for the study:

Trichloroacetyl chloride was purchased from Aldrich (Milwaukee, WI, USA).

Method

Target gene:

TA100 contains the base-substitution allele hisG46, which is the only allele of the Ames Salmonella strains that has detected the mutagenic activity of TCAC.

Species / strain

Species / strain / cell type:

S. typhimurium TA 100

Metabolic activation:

with and without

Metabolic activation system:

post-mitochondrial fraction (S9 fraction) obtained from a liver microsomal fraction of rats induced with Aroclor 1254

Test concentrations with justification for top dose:

With S9: 0, 100, 200, 300, 400 ppm
Without S9: 0, 100, 200, 300, 400, 500, 600, 700 ppm

Vehicle / solvent:

no data

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

no

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

other: 2-aminoanthracene

Details on test system and experimental conditions:

2.5 mL of top agar containing 100 µL of an overnight culture of strain TA100 (+/- 500 µL of S9 mix) were poured onto 50 mL of minimal medium in a 100-mm glass petri dish. After the top agar had hardened, the bottom and top parts of the petri dish were placed against each other, and the assembly was inserted into a Tedlar bag of known volume (600 - 800 mL) with the inverted top of the dish directly under the septum of the bag. The bag was then sealed, and various amounts of the test compound were injected through a septum on the bag into the inverted top of the petri dish. The bag was placed in a 37°C incubator for 24 h, after which the bag was opened, the two halves of the petri were reassembled, and the inverted plate was placed back in the incubator for an additional 48 h. Colonies were counted by an automatic colony counter (biotran II).
Each petri plate was in a separate bag, and two plates were exposed at each concentration of chemical tested. All experiments were performed at least twice. The concentration (p.p.m.) of the test chemical in the bag was calculated based on the volume of the bag and the amount (µL) and density (g/mL) of the test chemical injected into the bag.
A reproducible, 2-fold increase in revertants/plate relative to the background was considered a positive response.

Statistics:

Chi-square analysis

Results and discussion

Test results

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Trichloroacetyl chloride (TCAC) was tested to toxicity as indicated by a reduction in the number of revertants/plate relative to the background and/or a thinning of the background lawn of cells. TCAC (+/- S9) gave reproducible, mutagenic responses.
S9 had no effect on the mutagenic potency of TCAC.

Any other information on results incl. tables

Table 1: Mutagenic potencies of chemicals in Salmonella TA100

 

Chemical^a	Revertants/p.p.m. (r²)^a			LEC^b
	Experiment 1	Experiment 2	Mean
TCAC (- S9)	0.5 (0.99)	0.8 (0.84)	0.7	300
TCAC (+ S9)	0.9 (0.92)	0.7 (0.82)	0.8	200

a: Potencies are the slopes of the regression calculated over the linear portion of the dose-response curves in Figure 1.

b: Lowest effective concentration, i.e. the concentration (p.p.m.) producing a 2 -fold increase in rev/plate relative to the background.

Applicant's summary and conclusion

Conclusions:

In these test conditions, Trichloroacetyl chloride is mutagenic for the strain TA100 with and without metabolic activation.

Executive summary:

The mutagenicity of Trichloroacetyl chloride (TCAC) (volatilde compound) in strain TA100 of Salmonella typhimurium with and without metabolic activation, was evaluated using the vaporization technique.

TCAC was tested to toxicity as indicated by a reduction in the number of revertants/plate relative to the background and/or a thinning of the background lawn of cells. TCAC (+/- S9) gave reproducible, mutagenic responses.

In these test conditions, TCAC is mutagenic for the strain TA100 with and without metabolic activation.