1,2-dichlorobenzene

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP - Guideline study

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2001

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

1,2-dichlorobenzene

EC Number:

202-425-9

EC Name:

1,2-dichlorobenzene

Cas Number:

95-50-1

Molecular formula:

C6H4Cl2

IUPAC Name:

1,2-dichlorobenzene

Details on test material:

- Name of test material (as cited in study report): 1,2-dichlorobenzene
- Analytical purity: 99.7%

Method

Species / strain

Species / strain / cell type:

other: Salmonella typhimurium TA100, TA1535, TA98, TA1537, Escherichia coli WP2 uvrA.

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S9: Rat liver, induced with phenobarbital and 5,6-benzoflavone

Test concentrations with justification for top dose:

-S9 mix: 0, 2.44, 4.88, 9.77, 19.5, 39.1, 78.1 µg/plate (TA100)
-S9 mix: 0, 9.77, 19.5, 39.1, 78.1, 156, 313 µg/plate (TA1535, WP2 uvr A, TA98, TA1537)
+S9 mix: 0, 9.77, 19.5, 39.1, 78.1, 156, 313µg/plate (all strains)

Vehicle / solvent:

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

Controls

Untreated negative controls:

other: not examinated

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: -S9 mix: 2-(2-Furyl)-3-(5-nitro-2-furyl)acrylamide (TA100, TA98, and WP2 uvrA), Sodium azide (TA1535) and 9-aminoacridine hydrochloride (TA1537). + S9 mix: 2-Aminoantracene (all strains).

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

NUMBER OF REPLICATIONS: 2

DETERMINATION OF CYTOTOXICITY
- Method: other: growth inibition

Evaluation criteria:

No data

Statistics:

No data

Results and discussion

Test results

Test results 1

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Any other information on results incl. tables

Test results: No increase in revertant colonies was observed in the test with either the non-activation method (-S9) or activation (+S9)

Genetic effects: Salmonella typhimurium TA100, TA1535, TA98, TA1537

+ ? -

Without metabolic activation:        [ ] [ ] [*]

With metabolic activation:             [ ] [ ] [*]

Genetic effects: Escherichia coli WP2 uvrA

+       ?     -

Without metabolic activation:          [ ]    [ ]   [*]

With metabolic activation:               [ ] [ ] [*]

Table 1. Results of the bacterial reversion of test of o-dichlorobenzene (1st trial) [direct method:-S9 mix]

		Revertant colonies per plate [Mean± SD]
Compound	Dose [µg/plate]	TA100	TA1535	WP2 uvrA	TA98	TA1537
Test substance	0	99 88 91 [93±6]	13 15 14 [14±1]	24 23 24 [24±1]	17 24 23 [21±4]	9 11 8 [9± 2]
	2.44	82 90 95 [89 ± 7]
	4.88	100 86 81 [89 ± 10]
	9.77	100 83 95 [93 ± 9]	17 11 11[13 ± 3]	28 22  33[28 ± 6]	14 20 14 [16 ± 3]	10 7 6 [8 ± 2]
	19.5	92 85 99[92 ± 7]	13  19 14[15 ± 3]	31 23 24[26 ± 4]	17 16 13[15 ± 2]	10 9 8 [9 ± 1]
	39.1	85 95 85[88 ± 6]	12 14 10[12 ± 2]	25 25 29 [26 ± 2]	13 18 13[15 ± 3]	7 7 7 [7 ±0]
	78.1	83* 72* 72*[76 ± 6]	11 12 13[12 ± 1]	21 22 25 [23 ± 2]	17 13 13 [14 ± 2]	6 6 8 [7  ± 1]
	156		10* 6 * 9*[8 ± 2]	25 23 23[24 ± 1]	11* 11* 7*[10 ± 2]	3 * 3* 3* [3 ± 0]
	313		8* 7* 7*[7 ± 1]	15 * 20* 13*[16 ± 4]	6* 2* 6*[5 ± 2]	1 * 3* 2*[2 ± 1]
Positive contrrol		548 541 559^a[549 ± 9]	455 473 469^b[466 ± 9]	134 161 153 ^a[149 ± 14]	644 640 655^c[646 ± 8]	609 599 601^d[603 ± 5]

a) AF-2: 2 -(2 -Furyl)-3 -(5 -nitro-2 -furyl)acrylamide, 0.01µ/plate

b) NaN3: Sodium azide, 0.5µg/plate

c) AF-2: 0.1µg/plate

d) 9 -AA: 9 -Aminoacridine hydrochloride, 80µg/plate

*: growth inhibition was observed

Table 2. Results of the bacterial reversion of test of o-dichlorobenzene (1st trial) [activation method:+S9 mix]

		Revertant colonies per plate [Mean± SD]
Compound	Dose [µg/plate]	TA100	TA1535	WP2 uvrA	TA98	TA1537
Test substance	0	107 102 103[104 ± 3]	16 14 11[14 ± 3]	26 23 25[25 ± 2]	29 27 28 [28 ± 1]	13 14 16[14 ± 2]
	9.77	111 108 110 [110 ± 2]	10 11 10[10 ± 1]	26 31 27 [28 ± 3]	24 28 30 [27 ± 3]	10 14 12[12 ± 2]
	19.5	112 117 133[121 ± 11]	14 14 11[13 ± 2]	22 26 27 [25 ± 3]	28 27 27 [27 ± 1]	11 16 10[12 ± 3]
	39.1	127 128 128 [128  ± 1]	16 10 16 [14 ± 3]	33 29 33[32 ± 2]	24 25 27 [25 ± 2]	17 14 17 [16 ± 2]
	78.1	124 135 136[132 ± 7]	14 10 12[12 ± 2]	32 23 27[27 ± 5]	29 31 30[30 ± 1]	10 11 15[12 ± 3]
	156	114 * 119* 138*[124 ± 13]	10* 7* 9*[9 ± 2]	28 35 35[33 ± 1]	33* 33* 34*[33 ± 1]	15* 8* 12*[12 ± 4]
	313	74* 90*91*[85 ± 10]	7* 10* 10*[9 ± 2]	30* 28*28*[29 ± 1]	14* 16* 15*[15 ± 1]	17* 11* 13*[14 ± 3]
Positive control		775 806 840^a[807 ± 33]	361 392 364^b[372 ± 17]	813 833 816^c[821 ± 11]	489 467 403^d[453 ± 45]	179 181 173^b[178 ± 4]

a) 2 -AA: 2 -Aminoanthracene, 1 µg/plate

b) 2 -AA, 2 µg/plate

c) 2 -AA , 10 µg/plate

d) 2 -AA, 0.5 µg/plate

*: Growth inhibition was observed

Table 3. Results of the bacterial reversion of test of o-dichlorobenzene (2nd trial) [direct method:-S9 mix]

		Revertant colonies per plate [Mean± SD]
Compound	Dose [µg/plate]	TA100	TA1535	WP2 uvrA	TA98	TA1537
Test substance	0	104 103 108 [105 ± 3]	13 17 10 [13  ± 4]	30 31 25[29  ± 3]	21 17 18 [19  ± 2]	8 9 7 [8 ± 1]
	2.44	114 95 103 [104 ± 10]
	4.88	91 113 117[107 ± 14]
	9.77	123 108 117 [116 ± 8]	8 10 12[10 ± 2]	28 31 32[30 ± 2]	14 16 17[16 ± 2]	11 13 8[11 ± 3]
	19.5	132 88 116[112 ± 22]	11 12 11[11 ± 1]	33 30 32[32 ± 2]	17 18 15[17 ± 2]	11 11 11[11 ± 0]
	39.1	86 123 112[107  ± 19]	8 14 14[12 ± 3]	37 31 32[33 ± 3]	14 14 15 [14  ± 1]	9 10 9[9 ± 1]
	78.1	103* 92* 97*[97 ± 6]	10 9 12 [10 ± 2]	25 26 26[26  ± 1]	11 14 13 [13 ± 2]	10 11 13[11 ± 2]
	156		8 * 8* 9*[8 ± 1]	30* 35* 31*[32 ± 3]	17* 12* 12*[14 ± 3]	6* 5* 6*[6 ± 1]
	313		5* 8* 3*[5 ± 3]	17* 15* 14*[15 ± 2]	1* 5* 5*[4 ± 2]	1* 3* 2*[2 ± 1]
Positive control		600 554 590^a[581 ± 24]	434 488 449^b[457 ± 28]	158 153 154^a[155 ± 3]	540 544 541^c[542 ± 2]	593 592 579^d[588  ± 8]

a) AF-2: 2 -(2 -Furyl)-3 -(5 -nitro-2 -furyl)acrylamide, 0.01µg/plate

b) NaN3: Sodium azide, 0.5µg/plate

c) AF-2: 0.1µg/plate

d) 9 -AA: 9 -Aminoacridine hydrochloride, 80µg/plate

*: growth inhibition was observed

Table 4 Results of the bacterial reversion test of o-dichlorobenzene (2nd trial) [activation method:+S9 mix]

		Revertant colonies per plate [Mean± SD]
Compound	Dose[µg/plate]	TA100	TA1535	WP2 uvrA	TA98	TA1537
Test substance	0	108 98 100[102 ± 5]	14 17 18[16 ± 2]	28 29 28[28 ± 1]	32 31 33[32 ± 1]	11 10 12[11 ± 1]
	9.77	100 118 91[103 ± 14]	10 14 12 [12 ± 2]	33 25 36 [31 ± 6]	33 30 28 [30 ± 3]	15 13 14[14 ± 1]
	19.5	115 134 118 [122 ± 10]	13 15 18 [15  ± 3]	42 30 40 [37  ± 6]	39 43 42[41 ± 2]	11 14 13[13 ± 2]
	39.1	147 137 112[132 ± 18]	12 13 12[12 ± 1]	23 28 29[27 ± 3]	30 35 29[31 ± 3]	14 14 13[14 ± 1]
	78.1	123 136 138 [132 ± 8]	15 10 12[12 ± 3]	32 38 32 [34 ± 3]	39 36 44[40  ± 4]	13 13 10[12 ± 2]
	156	152 * 155* 132*[146 ± 13]	8* 13* 11*[11 ± 3]	29 34 29 [31 ± 3]	38 * 40* 33*[37 ± 4]	11* 10* 9*[10 ± 1]
	313	115* 74* 79*[89 ± 22]	8* 7* 5*[7 ± 2]	36* 32* 32*[33 ± 2]	17* 19* 18*[18 ± 1]	13* 10 * 9*[11 ± 2]
Positive control		790 779 783^a[784 ± 6]	373 395 382^b[383 ± 11]	756 816 828^c[800 ± 39]	502 499 480^d[494 ± 12]	162 168 164^b[165 ± 3]

a) 2 -AA: 2 -Aminoanthracene, 1 µg/plate

b) 2 -AA, 2 µg/plate

c) 2 -AA , 10 µg/plate

d) 2 -AA, 0.5 µg/plate

*: Growth inhibition was observed

Applicant's summary and conclusion

Conclusions:

Interpretation of results: negative

Executive summary:

Masumori et al., 2001

The mutagenicity of 1,2-dichlorobenzene in was examinated in Salmonella typhimurium, and Escherichia coli WP2 uverA. 5 strains TA98, TA 1537, TA 100 and TA 1535 were used for detection of mutagens that cause frameshift mutations.1,2-dichlorobenzene was tested at the following concentrations:

-S9 mix: 0, 2.44, 4.88, 9.77, 19.5, 39.1, 78.1 µg/plate (TA100)

-S9 mix: 0, 9.77, 19.5, 39.1, 78.1, 156, 313 µg/plate (TA1535, WP2 uvr A, TA98, TA1537)

+S9 mix: 0, 9.77, 19.5, 39.1, 78.1, 156, 313µg/plate (all strains).

In this study 1,2-dichlorobenzene have been reported to be non-mutagenic in the strains tested. The test was conducted according to OECD Guideline 471 and Japanese "Guidelines for Screening Mutagenicity Testing Of Chemicals" without restrictions restrictions.