methyl (2E)-[2-(chloromethyl)phenyl](methoxyimino)acetate

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: Guideline study with GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes

Remarks:

BASF AG, Experimental Toxicology and Ecology

Type of assay:

bacterial reverse mutation assay

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

- Name of test material (as cited in study report): 520 F-Chlormethyloximether (Stufe 9 der BAS 520 FSynthese)
- Physical state: crystalline / grey
- Analytical purity: 98.3 g/100 g
- Lot/batch No.: 29388-136
- Storage condition of test material: room temperature

Method

Target gene:

histidine and tryptophan auxotrophy

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254 induced rat liver S-9 mix

Test concentrations with justification for top dose:

1st experiment, Standard plate test (with and without metabolic activation): 0, 20, 100, 500, 2500 and 5000 µg/plate
2nd experiment, Standard plate test (with and without metabolic activation): 0, 1000, 2000, 4000, 6000 and 8000 µg/plate
3rd experiment, Preincubation test (with and without metabolic activation): 0, 20, 100, 500, 2500 and 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: Due to the insolubility of the test substance in water, DMSO was selected as the vehicle, which had been demonstrated to be suitable in bacterial reverse mutation tests and for which historical control data are available.

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene (2-AA), 2.5-60 µg/ml for all strains

Remarks:

with S9 mix

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: N-methyl-N-nitro-N-nitrosoguanidine (MNNG), 5 µg/plate for TA1535 and TA100

Remarks:

without S9 mix

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: 4-nitro-o-phenylendiamine (NOPD), 10 µg/plate for TA98

Remarks:

without S9 mix

Controls 4

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

without S9 mix

Migrated to IUCLID6: 100 µg/plate for TA1537

Controls 5

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

without S9 mix

Migrated to IUCLID6: 5 µg/ml for E. coli WP2 uvrA

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation); preincubation


DURATION
The experimental procedure of the Standard Plate Test (plate incorporation method) was based on the method of Ames et al (Mut. Res., 31 347 -364, 1975). The experimental procedure of the Preincubation Test was based on the method described by Yahagi et al. (Mut. Res., 48 121 - 130, 1977) and Matsushima et al. (In: Norpoth, K.H. and R.C. Garner, Short-Term Test Systems for Detecting Carcinogens. Springer Verlag Berlin, Heidelberg, New York, 1980).


NUMBER OF REPLICATIONS: 3

Evaluation criteria:

- The test chemical is considered positive in this assay if a dose-related and reproducible increase in the number of revertant colonies, i.e. about doubling of the spontaneous mutation rate in at least one tester strains either without S-9 mix or after adding a metabolizing system.
- A test substance is generally considered non-mutagenic in this test if the number of revertants for all tester strains were within the historical negative control range under all experimental conditions in two experiments carried out independently of each other.

Results and discussion

Test results

Test results 1

Species / strain:

other: S. typhimurium TA 1535, TA 1537, TA 98, TA 100, and E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

from 500 µg/plate onwards in the preincubation assay

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Test results 2

Species / strain:

other: S. typhimurium TA 1535, TA 1537, TA 98, TA 100, and E. coli WP2 uvr A

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

at 8000 µg/plate only using TA 100 in the standard plate test

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: No test substance precipitation was found


RANGE-FINDING/SCREENING STUDIES: Dose selection used in repeat studies or further experiments were based an the findings of the 1st experiment.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Expt. 1: Standard plate test: Mean Revertants/ plate (±SE)

Dose (µg/plate)	TA 98		TA 100		TA 1535		TA 1537		WP2uvrA
	-S9	+S9	-S9	+S9	-S9	+S9	-S9	+S9	-S9	+S9
0	30±4	41±6	141±9	147±3	17±1	21±2	11±2	9±2	27±4	33±3
20	24±7	32±2	141±12	151±10	20±5	20±4	8±2	9±1	28±7	29±6
100	23±3	33±7	146±14	173±37	22±2	23±4	8±3	13±1	28±3	39±2
500	24±4	26±5	139±11	154±8	28±3	19±2	10±3	11±2	29±4	34±2
2500	25±5	26±6	185±9	172±18	25±5	23±4	10±3	6±3	26±4	28±3
5000	18±2	24±3	181±15	187±28	22±4	16±4	9±3	6±2	28±7	24±3
PC	984±58	969±69	641±48	1333±133	621±20	174±16	722±101	114±16	888±44	215±10

Expt. 2: Standard plate test: Mean Revertants/ plate (±SE)

Dose (µg/plate)	TA 100
	-S9	+S9
0	118±14	133±9
1000	134±16	144±17
2000	176±12	144±13
4000	126±15	168±21
6000	112±17	138±7
8000	79±20	91±3
PC	729±114	1480±70

Expt. 3: Pre-incubation test: Mean Revertants/ plate (±SE)

Dose (µg/plate)	TA 98		TA 100		TA 1535		TA 1537		WP2uvrA
	-S9	+S9	-S9	+S9	-S9	+S9	-S9	+S9	-S9	+S9
0	34±3	28±3	124±5	117±9	18±1	18±4	9±3	12±2	23±3	27±2
20	29±4	32±3	105±11	114±15	19±3	21±4	9±2	12±3	21±7	24±5
100	26±2	27±3	119±10	102±10	20±1	17±1	10±1	9±3	19±2	23±3
500	27±6	24±4	92±5	78±3	21±5	13±2	9±1	10±2	22±3	17±5
2500	26±2	26±4	108±4	99±8	22±4	15±4	7±3	7±1	20±3	15±2
5000	19±2	23±2	84±1	110±5	19±2	13±1	6±2	6±1	14±5	17±4
PC	894±94	1023±70	1626±55	649±43	1310±112	114±10	704±21	118±20	699±83	208±17

An increase in the number of his+ or trp+ revertants was not observed both in the standard plate test and in the pre-incubation test either without S-9 mix or after the addition of a metabolizing system. According to the results of the present study, the test substance 520 F-Chlormethyloximether (Stufe 9 der BAS 520 F-Synthese) is not mutagenic in the Salmonella typhimurium/ Escherichia coli reverse mutation assay under the experimental conditions chosen here.