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Study Information
Study Attribute Value
CEBS Accession Number: 002-02237-0003-0000-9
Chemical Name: Heptachlor
CASRN: 76-44-8
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 616642_SCE
Study Result: Not a Valid Test

Study Result: Not a Valid Test
Activation Trial Trial Call
No Activation  1  Weakly Positive 
No Activation  2  Test Failure 
Induced Rat Liver S9  1_S9  Test Failure 

Trial #: 1    Activation: No Activation    Date: 08/02/1983    Trial Call: Weakly Positive   
  Dose
µg/mL		 Number
Cells
Examined		 Number
Chromosomes
Examined		 Total
Number
SCEs		 SCE /
Chromosome		 SCE /
Cell		 Hours in
BRDU		 % Increase
Over Solvent
Control
Vehicle Control Dimethyl Sulfoxide 
0         
 50 1050 488 0.465 9.76 25.5 0.000
Test Chemical Heptachlor 
 0.83      
 50 1040 487 0.468 9.74 25.5 0.755 
2.5       
 50 1046 483 0.462 9.66 25.5 -0.646 
8.33      
 50 1046 624 0.597 12.48 33.2 28.358
Positive Control Mitomycin-C 
 0.001     
 50 1041 710 0.682 14.20 25.5 46.750
Mitomycin-C 
 0.01      
 5 107 202 1.888 40.40 25.5 306.197
Trend: 4.035        
Probability: 0.000        

Trial #: 2    Activation: No Activation    Date: 08/24/1983    Trial Call: Test Failure   
  Dose
µg/mL		 Number
Cells
Examined		 Number
Chromosomes
Examined		 Total
Number
SCEs		 SCE /
Chromosome		 SCE /
Cell		 Hours in
BRDU		 % Increase
Over Solvent
Control
Vehicle Control Dimethyl Sulfoxide 
0         
 50 1049 538 0.513 10.76 25.5 0.000
Test Chemical Heptachlor 
12.5       
 50 1047 707 0.675 14.14 34.5 31.664 
15         
 50 1037 743 0.716 14.86 34.5 39.702 
20         
 50 1027 681 0.663 13.62 34.5 29.291 
25         
 0 0 0 0.000 0.00 34.5 N/A
Positive Control Mitomycin-C 
 0.001     
 50 1042 765 0.734 15.30 25.5 43.149
Mitomycin-C 
 0.01      
 5 105 188 1.790 37.60 25.5 249.110
Trend: 4.212        
Probability: 0.000        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 08/02/1983    Trial Call: Test Failure   
  Dose
µg/mL		 Number
Cells
Examined		 Number
Chromosomes
Examined		 Total
Number
SCEs		 SCE /
Chromosome		 SCE /
Cell		 Hours in
BRDU		 % Increase
Over Solvent
Control
Vehicle Control Dimethyl Sulfoxide 
0         
 50 1051 527 0.501 10.54 25.5 0.000
Test Chemical Heptachlor 
2.5       
 50 1048 530 0.506 10.60 25.5 0.857 
8.3       
 50 1049 647 0.617 12.94 33.3 23.004 
25         
 50 1043 837 0.802 16.74 33.3 60.042
Positive Control Cyclophosphamide 
 0.4       
 50 1037 817 0.788 16.34 25.5 57.121
Cyclophosphamide 
2         
 5 104 249 2.394 49.80 25.5 377.483
Trend: 9.382        
Probability: 0.000