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Study Information
Study Attribute Value
CEBS Accession Number: 002-01223-0002-0000-2
Chemical Name: 2,4-Dichlorophenoxyacetic acid
CASRN: 94-75-7
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 079515_CA
Study Result: Positive

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

Trial #:1   Activation: No Activation    Date: 04/08/1982    Harvest Time: 19.3 hour(s)   Trial Call: Negative   
  Dose
µg/mL		 Total
Cells Examined		 Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs
Vehicle Control: Negative (Not Specified) 
0         
 100 2 0.020 2.0 2 0.020 2.0 0 0.000 0.0 0 0.000 0.0
Dimethyl Sulfoxide 
0         
 100 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0 0 0.000 0.0
Test Chemical: 2,4-Dichlorophenoxyacetic acid 
696         
 100 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0 0 0.000 0.0 
800         
 100 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 
920         
 100 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
Positive Control: Mitomycin-C 
 0.062     
 50 32 0.640 32.0 16 0.320 24.0 6 0.120 12.0 10 0.200 0.0
Trend: -1.268 -1.268 0.000  
Probability: 0.898 0.898 0.000  


Trial #:1_S9   Activation: Induced Rat Liver S9    Date: 04/05/1982    Harvest Time: 10.5 hour(s)   Trial Call: Positive   
  Dose
µg/mL		 Total
Cells Examined		 Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs
Vehicle Control: Negative (Not Specified) 
0         
 100 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0 0 0.000 0.0
Dimethyl Sulfoxide 
0         
 100 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
Test Chemical: 2,4-Dichlorophenoxyacetic acid 
1900         
 100 2 0.020 2.0 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0 
2400         
 100 11 0.110 9.0 8 0.080 7.0 3 0.030 2.0 0 0.000 0.0 
3000         
 100 17 0.170 14.0 10 0.100 8.0 7 0.070 6.0 0 0.000 0.0
Positive Control: Cyclophosphamide 
25         
 50 11 0.220 20.0 7 0.140 14.0 4 0.080 8.0 0 0.000 0.0
Trend: 4.528 3.431 2.856  
Probability: 0.000 0.000 0.002  


Trial #:2   Activation: No Activation    Date: 03/16/1982    Harvest Time: 19 hour(s)   Trial Call: Negative   
  Dose
µg/mL		 Total
Cells Examined		 Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs
Vehicle Control: Negative (Not Specified) 
0         
 100 1 0.010 1.0 0 0.000 0.0 0 0.000 0.0 1 0.010 1.0
Dimethyl Sulfoxide 
0         
 100 2 0.020 2.0 2 0.020 2.0 0 0.000 0.0 0 0.000 0.0
Test Chemical: 2,4-Dichlorophenoxyacetic acid 
500         
 100 1 0.010 1.0 0 0.000 0.0 1 0.010 1.0 0 0.000 0.0 
600         
 100 7 0.070 6.0 4 0.040 4.0 2 0.020 2.0 1 0.010 1.0 
700         
 100 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0 0 0.000 0.0
Positive Control: Mitomycin-C 
 0.062     
 50 19 0.380 28.0 12 0.240 22.0 7 0.140 14.0 0 0.000 0.0
Trend: 0.367 0.233 0.311  
Probability: 0.357 0.408 0.378  


Trial #:2_S9   Activation: Induced Rat Liver S9    Date: 03/16/1982    Harvest Time: 19 hour(s)   Trial Call: Negative   
  Dose
µg/mL		 Total
Cells Examined		 Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs		 No. of
Abs.		 Abs
Per
Cell		 % Cells
With
Abs
Vehicle Control: Negative (Not Specified) 
0         
 100 2 0.020 2.0 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0
Dimethyl Sulfoxide 
0         
 100 2 0.020 2.0 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0
Test Chemical: 2,4-Dichlorophenoxyacetic acid 
4200         
 100 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0 0 0.000 0.0 
4500         
 100 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0 0 0.000 0.0 
5000         
 100 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0 0 0.000 0.0
Positive Control: Cyclophosphamide 
10         
 50 9 0.180 18.0 5 0.100 10.0 3 0.060 6.0 1 0.020 1.0
Trend: -0.593 0.000 -1.320  
Probability: 0.724 0.500 0.907