Bromochloromethane

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:

weight of evidence

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Test method equivalent or similar to OECD Guideline 471. Deviations: Only 4 Salmonella strains were tested.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1987

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

(Only 4 Salmonella typhimurium strains were tested).

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Bromochloromethane

EC Number:

200-826-3

EC Name:

Bromochloromethane

Cas Number:

74-97-5

Molecular formula:

CH2BrCl

IUPAC Name:

bromo(chloro)methane

Details on test material:

- Name of test material (as cited in study report): bromochloromethane.

Method

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 97

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 98

Species / strain 3

Species / strain / cell type:

S. typhimurium TA 100

Species / strain 4

Species / strain / cell type:

S. typhimurium, other: TA 104

Metabolic activation:

with and without

Metabolic activation system:

S-9 mix (from rat livers with Aroclor 1254-pretreatment).

Test concentrations with justification for top dose:

10, 25, 50, 100, 250, 500 and 1000 µg/plate

Vehicle / solvent:

- Solvent used: Dimethyl sulfoxide (DMSO).

Controls

Negative solvent / vehicle controls:

yes

Remarks:

DMSO.

Positive controls:

yes

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation). The test compound was added on top agar in a volume of 0.1 ml.
NUMBER OF REPLICATIONS: 2 or 3

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 97

Metabolic activation:

with and without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

(at 1000 µg/plate)

Vehicle controls validity:

valid

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

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium, other: TA 104

Metabolic activation:

with and without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle 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

Table 1. Mutagenicity of bromochloromethane (Ames-test).

Compound	Dose µg/plate	his^+revertant colònies in strain
		TA 97		TA 98		TA 100		TA 104
		- S9	+S9	- S9	+S9	- S9	+S9	- S9	+S9
Bromochloromethane	1000	580 ± 21	tox.	78 ± 6	124 ± 4	340 ± 21	820 ± 28	746 ± 12	703 ± 21
	500	680 ± 14	504 ± 19	40 ± 8	118 ± 5	436 ± 24	936 ± 26	748 ± 14	582 ± 17
	250	852 ± 27	688 ± 21	23 ± 7	108 ± 6	392 ± 27	1000 ± 27	968 ± 17	672 ± 14
	100	1030 ± 38	890 ± 26	32 ± 4	132 ± 9	379 ± 28	840 ± 21	940 ± 21	580 ± 13
	50	740 ± 24	798 ± 25	25 ± 6	146 ± 8	354 ± 21	920 ± 19	1136 ± 28	608 ± 10
	25	822 ± 28	668 ± 23	20 ± 9	120 ± 9	331 ± 16	862 ± 21	1388 ± 31	640 ± 9
	10	888 ± 24	632 ± 23	21 ± 6	90 ± 10	173 ± 14	800 ± 20	600 ± 12	600 ± 8

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
positive

The results of the bacterial reverse mutation assay on the test substance bromochloromethane were positive.

Executive summary:

A bacterial reverse mutation assay: plate incorporation method was performed with the test substance bromochloromethane. Salmonella typhimurium strains TA97 TA98, TA100 and TA 104 were exposed to 10 to 1000 ug/plate of the test substance with and without metabolic activation (S-9 mix). Negative and positive controls were included in the assay. Bromochloromethane showed positive responses in all the strain tested, with and without metabolic activation. Responses in TA 98 and TA 100 strains were enhanced with metabolic activation.