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Study Information
Study Attribute Value
CEBS Accession Number: 002-03187-0001-0000-2
Chemical Name: p-Phenylenediamine dihydrochloride
CASRN: 624-18-0
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 921738_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  Negative 
Induced Rat Liver S9  2_S9  Weakly Positive 

Trial #: 1    Activation: No Activation    Date: 09/11/1983    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 Medium 
0         
 50 1042 408 0.392 8.16 26.0 0.000
Negative (Not Specified) 
0         
 50 1043 379 0.363 7.58 26.0 -7.197
Test Chemical p-Phenylenediamine dihydrochloride 
 0.16      
 50 1043 420 0.403 8.40 26.0 2.842 
 0.5       
 50 1043 510 0.489 10.20 26.0 24.880 
1.6       
 50 1044 562 0.538 11.24 26.0 37.481 
5         
 50 1044 727 0.696 14.54 26.0 77.845 
16         
 0 0 0 0.000 0.00 26.0 N/A
Positive Control Mitomycin-C 
 0.005     
 50 1044 1570 1.504 31.40 26.0 284.067
Mitomycin-C 
 0.01      
 50 1050 2754 2.623 55.08 26.0 569.857
Trend: 10.722        
Probability: 0.000        

Trial #: 2    Activation: No Activation    Date: 10/18/1983    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 Medium 
0         
 50 1044 432 0.414 8.64 26.0 0.000
Negative (Not Specified) 
0         
 50 1043 419 0.402 8.38 26.0 -2.916
Test Chemical p-Phenylenediamine dihydrochloride 
5         
 50 1031 517 0.501 10.34 26.0 21.185 
10         
 50 1041 775 0.744 15.50 31.0 79.915 
15         
 50 1045 1214 1.162 24.28 43.5 180.750 
25         
 50 1030 2176 2.113 43.52 43.5 410.550 
50         
 50 1037 2376 2.291 47.52 43.5 453.713
Positive Control Mitomycin-C 
 0.005     
 50 1045 1377 1.318 27.54 26.0 218.445
Mitomycin-C 
 0.005     
 50 1048 1532 1.462 30.64 26.0 253.276
Trend: 50.607        
Probability: 0.000        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 09/11/1983    Trial Call: Negative   
  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 Medium 
0         
 50 1046 406 0.388 8.12 26.0 0.000
Negative (Not Specified) 
0         
 50 1050 436 0.415 8.72 26.0 6.980
Test Chemical p-Phenylenediamine dihydrochloride 
50         
 50 1034 360 0.348 7.20 26.0 -10.301 
160         
 50 1033 394 0.381 7.88 26.0 -1.734 
500         
 50 1038 432 0.416 8.64 26.0 7.224 
1000         
 50 1038 440 0.424 8.80 26.0 9.210
Positive Control Cyclophosphamide 
2         
 50 1043 2138 2.050 42.76 26.0 428.116
Cyclophosphamide 
3         
 50 1050 2880 2.743 57.60 26.0 606.657
Trend: 2.284        
Probability: 0.011        

Trial #: 2_S9    Activation: Induced Rat Liver S9    Date: 10/18/1983    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 Negative (Not Specified) 
0         
 50 1037 469 0.452 9.38 26.0 -0.387
Medium 
0         
 50 1044 474 0.454 9.48 26.0 0.000
Test Chemical p-Phenylenediamine dihydrochloride 
400         
 50 1045 519 0.497 10.38 26.0 9.389 
500         
 50 1042 471 0.452 9.42 26.0 -0.442 
750         
 50 1036 514 0.496 10.28 26.0 9.276 
1000         
 50 1045 674 0.645 13.48 26.0 42.058
Positive Control Cyclophosphamide 
1.5       
 50 1043 2080 1.994 41.60 26.0 339.239
Cyclophosphamide 
2         
 50 1043 2296 2.201 45.92 26.0 384.853
Trend: 5.627        
Probability: 0.000