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Study Information
Study Attribute Value
CEBS Accession Number: 002-03010-0001-0000-7
Chemical Name: Xylenes (mixed)
CASRN: 1330-20-7
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 744839_SCE
Study Result: Negative

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

Trial #: 1    Activation: No Activation    Date: 06/03/1986    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 1026 427 0.416 8.54 25.5 0.000
Test Chemical Xylenes (mixed) 
5         
 50 1002 399 0.398 7.98 25.5 -4.319 
16.7       
 50 1032 455 0.441 9.10 25.5 5.938 
50         
 50 1023 399 0.390 7.98 25.5 -6.283 
166.7       
 0 0 0 0.000 0.00 25.5 N/A
Positive Control Mitomycin-C 
 0.001     
 50 1013 589 0.581 11.78 25.5 39.709
Mitomycin-C 
 0.01      
 5 102 212 2.078 42.40 25.5 399.408
Trend: -0.366        
Probability: 0.643        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 06/03/1986    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 1031 410 0.398 8.20 25.5 0.000
Test Chemical Xylenes (mixed) 
5         
 50 1035 444 0.429 8.88 25.5 7.874 
16.7       
 50 1020 405 0.397 8.10 25.5 -0.154 
50         
 50 1035 415 0.401 8.30 25.5 0.828 
166.7       
 0 0 0 0.000 0.00 0.0 N/A
Positive Control Cyclophosphamide 
 0.4       
 50 1025 676 0.660 13.52 25.5 65.843
Cyclophosphamide 
2         
 5 106 150 1.415 30.00 25.5 255.844
Trend: -0.253        
Probability: 0.600