2,3-epoxybutane

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:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study (OECD), but non-GLP; restriction: E. coli not tested

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

only 4 strains tested

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

2,3-epoxybutane

EC Number:

221-877-8

EC Name:

2,3-epoxybutane

Cas Number:

3266-23-7

Molecular formula:

C4H8O

IUPAC Name:

2,3-dimethyloxirane

Details on test material:

- Name of test material (as cited in study report): n-Butylenoxid-2,3
- Test substance No.: 88/978
- Storage condition of test material: room temperature

Method

Target gene:

several S. typhimurium strains

Species / strain

Species / strain / cell type:

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

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254-induced rat liver S-9 mix

Test concentrations with justification for top dose:

20, 100, 500, 2500 and 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: with S-9 mix: 2-aminoanthracene; without S-9 mix: N-methyl-N'-nitro-Nnitroso-guanidine, 4-nitro-o-phenylenediamine and 9-aminoacridine chloride monohydrate

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48 h, 37°C

NUMBER OF REPLICATIONS: 3 test plates per dose or per control

Evaluation criteria:

In general, a substance to be characterized as positive in the Ames test has to fulfill the following requirements:
- doubling of the spontaneous mutation rate (control)
- dose-response relationship
- reproducibility of the results

Results and discussion

Test results

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

ambiguous

Remarks:

weakly positive for TA 100 and TA 1535 at >2500 µg/plate

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative 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

Results:

metabolic activation	TA98			TA100			TA1535			TA1537			TA1535 (trail 2)			TA1535 (trail 3)
	Trial 1	Trial 2	Trial 3	Trial 1	Trial 2	Trial 3	Trial 1	Trial 2	Trial 3	Trial 1	Trial 2	Trial 3	Trial 1	Trial 2	Trial 3	Trial 1	Trial 2	Trial 3
+	33	34	35	124	95	129	19	24	24	12	10	15	32	29	26	22	23	23
+	38	45	29	144	120	127	38	30	33	17	13	14	69	65	62	25	27	20
+	45	42	36	117	138	138	22	32	37	8	14	24	26	22	28	31	36	22
+	42	32	41	138	112	142	27	36	38	15	19	14	121	97	83	26	32	23
+	42	31	34	259	218	191	86	73	68	11	13	13	37	37	35	53	67	38
+	44	37	37	241	253	244	112	100	114	15	14	11	37	45	39	102	80	93
+	1150	1090	140	1500	1400	1460	125	133	131	177	182	146	1035	936	1015	660	960	680
-	30	32	34	90	99	116	13	20	24	10	14	12	23	25	27	21	27	19
-	34	22	24	107	98	110	25	27	35	12	7	12	41	22	31	30	19	24
-	27	29	38	140	116	129	36	38	35	9	8	12	37	41	45	19	11	26
-	36	30	40	132	126	145	50	44	33	14	15	9	49	32	47	34	23	26
-	47	40	31	168	180	172	70	66	69	11	17	9	52	49	42	61	57	46
-	35	37	32	296	238	203	162	127	90	23	18	15	60	56	80	68	73	75
-				1630	1650	1470	2100	2200	2250				795	895	925
-	670	760	850
-
-										506	518	614

Tests without S-9 mix:

TA 1535: Weakly positive reaction from about 100 µg/plate (factor 1.6 - 1.9 in the 1st and 2nd experiments) or from about 2500 µg/plate (factor 2.4; 3rd experiment) onward. Increase in the number of his+ revertants at 5000 µg/ plate by a factor of 2.8 - 6.6

TA 100: Weakly positive effect at 2500 µg - 5000 µg/plate

TA 1537, TA 98: No increase in the number of his + revertants

Tests with S-9 mix:

TA 1535: Mutagenicity was observed in the 1st and 3rd study at doses > 2500 µg/plate (factor 2.3 - 4.9). In the 2nd experiment increased values were found which did not show a dose-dependent effect.

TA 100: Weakly positive reaction at 2500 µg (factor 1.9) and 5000 µg (factor 2.1)

TA 1537, TA 98: No increase in the number of his+ revertants

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
ambiguous

According to the results of this study, n-Butylenoxid-2,3 is weakly mutagenic in the Ames test under the experimental conditions chosen here.