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Study Information
Study Attribute Value
CEBS Accession Number: 002-02563-0001-0000-9
Chemical Name: N-Nitrosomorpholine
CASRN: 59-89-2
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 579986_SCE
Study Result: Positive

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

Trial #: 1    Activation: No Activation    Date: 06/30/1987    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 Negative (Not Specified) 
0         
 50 1046 483 0.462 9.66 25.8 0.000
Test Chemical N-Nitrosomorpholine 
500.3       
 50 1032 425 0.412 8.50 25.8 -10.815 
1670         
 50 1039 488 0.470 9.76 25.8 1.716 
5000         
 50 1037 542 0.523 10.84 25.8 13.189
Positive Control Mitomycin-C 
 0.001     
 50 1037 538 0.519 10.76 25.8 12.354
Mitomycin-C 
 0.01      
 5 105 193 1.838 38.60 25.8 298.064
Trend: 2.521        
Probability: 0.006        

Trial #: 2    Activation: No Activation    Date: 09/06/1988    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 1049 411 0.392 8.22 25.6 0.000
Test Chemical N-Nitrosomorpholine 
500         
 50 1047 362 0.346 7.24 25.6 -11.754 
1670         
 50 1048 421 0.402 8.42 25.6 2.531 
5000         
 50 1047 438 0.418 8.76 30.8 6.773
Positive Control Mitomycin-C 
 0.001     
 50 1047 688 0.657 13.76 25.6 67.716
Mitomycin-C 
 0.01      
 5 104 258 2.481 51.60 25.6 533.170
Trend: 1.577        
Probability: 0.057        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 06/30/1987    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 Negative (Not Specified) 
0         
 50 1036 497 0.480 9.94 25.8 0.000
Test Chemical N-Nitrosomorpholine 
500.3       
 50 1047 564 0.539 11.28 25.8 12.289 
1670         
 50 1040 554 0.533 11.08 25.8 11.040 
5000         
 50 1045 596 0.570 11.92 25.8 18.887
Positive Control Cyclophosphamide 
 0.4       
 50 1041 690 0.663 13.80 25.8 38.166
Cyclophosphamide 
2         
 5 106 210 1.981 42.00 25.8 312.968
Trend: 2.620        
Probability: 0.004        

Trial #: 2_S9    Activation: Induced Rat Liver S9    Date: 07/22/1987    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 Negative (Not Specified) 
0         
 25 525 223 0.425 8.92 25.5 0.000
Test Chemical N-Nitrosomorpholine 
2500         
 25 526 327 0.622 13.08 25.5 46.358 
3750         
 25 524 347 0.662 13.88 25.5 55.902 
5000         
 25 522 307 0.588 12.28 25.5 38.459
Positive Control Cyclophosphamide 
 0.4       
 25 514 332 0.646 13.28 25.5 52.065
Cyclophosphamide 
2         
 5 105 149 1.419 29.80 25.5 234.081
Trend: 3.720        
Probability: 0.000