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Study Information
Study Attribute Value
CEBS Accession Number: 002-01690-0002-0000-0
Chemical Name: Benzene
CASRN: 71-43-2
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 603980_CA
Study Result: Negative

Study Result: Negative
Activation Trial Trial Call
No Activation  Negative 
Induced Rat Liver S9  1_S9  Negative 
No Activation  Negative 
Induced Rat Liver S9  2_S9  Negative 

Trial #:1   Activation: No Activation    Date: 12/02/1982    Harvest Time: 12 hour(s)   Trial Call: Negative   
  Dose
µg/mL
Total
Cells Examined
Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
Vehicle Control: Dimethyl Sulfoxide
0         
100 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0 0 0.000 0.0
Negative (Not Specified)
0         
100 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
Test Chemical: Benzene
100         
100 1 0.010 1.0 0 0.000 0.0 1 0.010 1.0 0 0.000 0.0
500         
100 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0 0 0.000 0.0
1000         
100 2 0.020 2.0 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0
2000         
0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
3000         
100 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0 0 0.000 0.0
Positive Control: Mitomycin-C
 0.5       
100 54 0.540 39.0 16 0.160 15.0 19 0.190 16.0 19 0.190 17.0
Trend: 0.270 0.422 -0.130  
Probability: 0.394 0.337 0.552  


Trial #:1_S9   Activation: Induced Rat Liver S9    Date: 12/02/1982    Harvest Time: 12.5 hour(s)   Trial Call: Negative   
  Dose
µg/mL
Total
Cells Examined
Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
Vehicle Control: Dimethyl Sulfoxide
0         
100 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
Negative (Not Specified)
0         
100 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0 0 0.000 0.0
Test Chemical: Benzene
500         
100 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
1000         
100 1 0.010 1.0 0 0.000 0.0 1 0.010 1.0 0 0.000 0.0
2000         
100 4 0.040 4.0 3 0.030 3.0 1 0.010 1.0 0 0.000 0.0
3000         
100 1 0.010 1.0 0 0.000 0.0 1 0.010 1.0 0 0.000 0.0
4000         
100 2 0.020 2.0 2 0.020 2.0 0 0.000 0.0 0 0.000 0.0
5000         
100 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
Positive Control: Cyclophosphamide
50         
100 79 0.790 40.0 17 0.170 16.0 43 0.430 27.0 19 0.190 13.0
Trend: 1.187 1.255 0.313  
Probability: 0.118 0.105 0.377  


Trial #:2   Activation: No Activation    Date: 11/04/1982    Harvest Time: 11.5 hour(s)   Trial Call: Negative   
  Dose
µg/mL
Total
Cells Examined
Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
Vehicle Control: Dimethyl Sulfoxide
0         
100 2 0.020 2.0 0 0.000 0.0 2 0.020 2.0 0 0.000 0.0
Negative (Not Specified)
0         
100 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0 0 0.000 0.0
Test Chemical: Benzene
16         
100 3 0.030 3.0 0 0.000 0.0 3 0.030 3.0 0 0.000 0.0
50         
100 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
160         
100 2 0.020 2.0 2 0.020 2.0 0 0.000 0.0 0 0.000 0.0
500         
100 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
1600         
100 2 0.020 2.0 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0
5000         
0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
Positive Control: Mitomycin-C
 0.25      
100 22 0.220 20.0 7 0.070 7.0 12 0.120 12.0 3 0.030 3.0
Trend: -0.683 1.190 -1.678  
Probability: 0.753 0.117 0.953  


Trial #:2_S9   Activation: Induced Rat Liver S9    Date: 11/04/1982    Harvest Time: 13.5 hour(s)   Trial Call: Negative   
  Dose
µg/mL
Total
Cells Examined
Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
Vehicle Control: Dimethyl Sulfoxide
0         
100 2 0.020 2.0 2 0.020 2.0 0 0.000 0.0 0 0.000 0.0
Negative (Not Specified)
0         
100 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
Test Chemical: Benzene
16         
100 1 0.010 1.0 0 0.000 0.0 1 0.010 1.0 0 0.000 0.0
50         
100 1 0.010 1.0 0 0.000 0.0 1 0.010 1.0 0 0.000 0.0
160         
100 1 0.010 1.0 0 0.000 0.0 1 0.010 1.0 0 0.000 0.0
500         
100 1 0.010 1.0 0 0.000 0.0 1 0.010 1.0 0 0.000 0.0
1600         
100 3 0.030 3.0 1 0.010 1.0 2 0.020 2.0 0 0.000 0.0
5000         
100 1 0.010 1.0 0 0.000 0.0 1 0.010 1.0 0 0.000 0.0
Positive Control: Cyclophosphamide
25         
100 33 0.330 25.0 11 0.110 10.0 11 0.110 11.0 11 0.110 9.0
Trend: 0.162 -1.154 0.951  
Probability: 0.436 0.876 0.171