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Toxicological information

Genetic toxicity: in vitro

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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

Constituent 1
Chemical structure
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 resultsopen allclose all
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
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 469b[466 ± 9]  134 161 153 a[149 ± 14] 644 640 655c[646 ± 8]  609 599 601d[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 840a[807 ± 33] 361 392 364b[372 ± 17] 813 833 816c[821 ± 11] 489 467 403d[453 ± 45]  179 181 173b[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 590a[581 ± 24] 434 488 449b[457 ± 28] 158 153 154a[155 ± 3]   540 544 541c[542 ± 2]  593 592 579d[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 783a[784 ± 6]  373 395 382b[383 ± 11]  756 816 828c [800 ± 39]  502 499 480d[494 ± 12] 162 168 164b[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.