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Study Information
Study Attribute Value
CEBS Accession Number: 002-03138-0001-0000-8
Chemical Name: o-Phenylenediamine
CASRN: 95-54-5
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 773292_SCE
Study Result: Positive

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

Trial #: 1    Activation: No Activation    Date: 12/18/1985    Trial Call: 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 1023 381 0.372 7.62 25.5 0.000
Test Chemical o-Phenylenediamine 
 0.2       
 25 513 552 1.076 22.08 32.0 188.917 
 0.5       
 50 1010 538 0.533 10.76 32.0 43.025 
1.7       
 0 0 0 0.000 0.00 32.0 N/A
Positive Control Mitomycin-C 
 0.001     
 50 1015 626 0.617 12.52 25.5 65.599
Mitomycin-C 
 0.01      
 5 102 147 1.441 29.40 25.5 286.962
Trend: 5.374        
Probability: 0.000        

Trial #: 2    Activation: No Activation    Date: 01/29/1986    Trial Call: 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         
 25 514 216 0.420 8.64 25.5 0.000
Test Chemical o-Phenylenediamine 
 0.5       
 25 505 204 0.404 8.16 25.5 -3.872 
1.5       
 25 500 256 0.512 10.24 25.5 21.837 
2         
 25 502 294 0.586 11.76 25.5 39.365
Positive Control Mitomycin-C 
 0.001     
 25 518 307 0.593 12.28 25.5 41.032
Mitomycin-C 
 0.01      
 5 102 222 2.176 44.40 25.5 417.919
Trend: 4.300        
Probability: 0.000        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 12/18/1985    Trial Call: 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 1018 381 0.374 7.62 25.5 0.000
Test Chemical o-Phenylenediamine 
166.7       
 50 1026 478 0.466 9.56 32.0 24.481 
500         
 50 1014 622 0.613 12.44 32.0 63.899 
1666.7       
 50 1019 849 0.833 16.98 32.0 122.616 
5000         
 50 1024 987 0.964 19.74 32.0 157.537
Positive Control Cyclophosphamide 
 0.4       
 50 1013 680 0.671 13.60 25.5 79.359
Cyclophosphamide 
2         
 5 103 229 2.223 45.80 25.5 494.047
Trend: 19.408        
Probability: 0.000