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Study Information
Study Attribute Value
CEBS Accession Number: 002-01730-0001-0000-4
Chemical Name: Biurea
CASRN: 110-21-4
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 805767_SCE
Study Result: Negative

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

Trial #: 1    Activation: No Activation    Date: 04/16/1984    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 1039 459 0.442 9.18 27.0 0.000
Negative (Not Specified) 
0         
 50 1045 425 0.407 8.50 27.0 -7.939
Test Chemical Biurea 
160         
 50 1042 441 0.423 8.82 27.0 -4.198 
500         
 50 1043 408 0.391 8.16 27.0 -11.452 
1600         
 50 1044 441 0.422 8.82 27.0 -4.382 
5000         
 9 187 73 0.390 8.11 27.0 -11.634
Positive Control Mitomycin-C 
 0.001     
 50 1048 1198 1.143 23.96 27.0 158.761
Mitomycin-C 
 0.01      
 10 209 729 3.488 72.90 27.0 689.558
Trend: -1.159        
Probability: 0.877        

Trial #: 2    Activation: No Activation    Date: 06/07/1984    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 1048 450 0.429 9.00 26.0 0.000
Negative (Not Specified) 
0         
 50 1050 440 0.419 8.80 26.0 -2.408
Test Chemical Biurea 
1600         
 50 1046 426 0.407 8.52 26.0 -5.152 
3000         
 50 1034 530 0.513 10.60 26.0 19.372 
4000         
 50 1047 452 0.432 9.04 26.0 0.540 
5000         
 50 1046 431 0.412 8.62 26.0 -4.039
Positive Control Mitomycin-C 
 0.0E-4    
 50 1051 881 0.838 17.62 26.0 95.219
Mitomycin-C 
 0.001     
 10 209 662 3.167 66.20 26.0 637.667
Trend: 0.511        
Probability: 0.305        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 04/16/1984    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 Negative (Not Specified) 
0         
 50 1043 433 0.415 8.66 26.0 -7.082
Medium 
0         
 50 1043 466 0.447 9.32 26.0 0.000
Test Chemical Biurea 
160         
 50 1044 435 0.417 8.70 26.0 -6.742 
500         
 50 1046 415 0.397 8.30 26.0 -11.200 
1600         
 50 1042 445 0.427 8.90 26.0 -4.415 
5000         
 50 1049 428 0.408 8.56 26.0 -8.680
Positive Control Cyclophosphamide 
 0.3       
 50 1047 633 0.605 12.66 26.0 35.318
Cyclophosphamide 
2         
 10 207 415 2.005 41.50 26.0 348.721
Trend: -1.056        
Probability: 0.855        

Trial #: 2_S9    Activation: Induced Rat Liver S9    Date: 06/07/1984    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 1050 434 0.413 8.68 26.0 0.000
Negative (Not Specified) 
0         
 50 1048 450 0.429 9.00 26.0 3.885
Test Chemical Biurea 
1600         
 50 1049 492 0.469 9.84 26.0 13.472 
3000         
 50 1048 458 0.437 9.16 26.0 5.731 
4000         
 50 1050 426 0.406 8.52 26.0 -1.843 
5000         
 50 1049 429 0.409 8.58 26.0 -1.058
Positive Control Cyclophosphamide 
 0.3       
 50 1052 548 0.521 10.96 26.0 26.027
Cyclophosphamide 
2         
 10 210 334 1.590 33.40 26.0 284.793
Trend: -1.097        
Probability: 0.864