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Study Information
Study Attribute Value
CEBS Accession Number: 002-03147-0001-0000-8
Chemical Name: p,p'-Dichlorodiphenyl dichloroethylene
CASRN: 72-55-9
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 354419_SCE
Study Result: Weakly Positive

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

Trial #: 1    Activation: No Activation    Date: 05/11/1982    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 Dimethyl Sulfoxide 
0         
 50 1006 464 0.461 9.28 25.5 0.000
Test Chemical p,p'-Dichlorodiphenyl dichloroethylene 
 0.5       
 50 1026 438 0.427 8.76 25.5 -7.444 
1.5       
 50 1021 509 0.499 10.18 25.5 8.087 
5         
 50 1018 505 0.496 10.10 25.5 7.553 
15         
 0 0 0 0.000 0.00 25.5 N/A
Positive Control Mitomycin-C 
 0.005     
 25 516 764 1.481 30.56 25.5 221.014
Trend: 1.824        
Probability: 0.034        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 05/11/1982    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 1038 425 0.409 8.50 25.5 0.000
Test Chemical p,p'-Dichlorodiphenyl dichloroethylene 
5         
 50 1044 542 0.519 10.84 25.5 26.796 
15         
 50 1022 497 0.486 9.94 25.5 18.772 
50         
 50 1037 596 0.575 11.92 32.2 40.371
Positive Control Cyclophosphamide 
1.5       
 25 515 828 1.608 33.12 25.5 292.673
Trend: 4.761        
Probability: 0.000        

Trial #: 2_S9    Activation: Induced Rat Liver S9    Date: 06/02/1982    Trial Call: Questionable   
  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 1026 493 0.481 9.86 25.5 0.000
Test Chemical p,p'-Dichlorodiphenyl dichloroethylene 
45         
 50 1027 536 0.522 10.72 25.5 8.616 
60         
 50 1023 515 0.503 10.30 25.5 4.769 
80         
 50 1022 586 0.573 11.72 32.5 19.329
Positive Control Cyclophosphamide 
1.5       
 25 518 980 1.892 39.20 25.5 293.728
Trend: 2.581        
Probability: 0.005