COVID-19 is an emerging, rapidly evolving situation.

Get the latest public health information from CDC and research information from NIH.

U.S. flag

An official website of the United States government

Dot gov

The .gov means it's official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you're on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Share This:
Study Information
Study Attribute Value
CEBS Accession Number: 002-02669-0002-0000-7
Chemical Name: Phenobarbital
CASRN: 50-06-6
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 539978_CA
Study Result: Positive

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

Trial #:1   Activation: No Activation    Date: 02/11/1983    Harvest Time: 12 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: Dimethyl Sulfoxide 
0         
 100 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0 0 0.000 0.0
Negative (Not Specified) 
0         
 100 2 0.020 2.0 0 0.000 0.0 2 0.020 2.0 0 0.000 0.0
Test Chemical: Phenobarbital 
250         
 100 3 0.030 3.0 2 0.020 2.0 1 0.010 1.0 0 0.000 0.0 
500         
 100 2 0.020 2.0 2 0.020 2.0 0 0.000 0.0 0 0.000 0.0 
1000         
 100 5 0.050 5.0 4 0.040 4.0 1 0.010 1.0 0 0.000 0.0 
2000         
 100 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 
3000         
 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 
 0.5       
 100 81 0.810 49.0 56 0.560 36.0 25 0.250 22.0 0 0.000 0.0
Trend: -0.927 -0.833 -0.401  
Probability: 0.823 0.797 0.656  


Trial #:1_S9   Activation: Induced Rat Liver S9    Date: 02/11/1983    Harvest Time: 12 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: Dimethyl Sulfoxide 
0         
 100 2 0.020 2.0 0 0.000 0.0 2 0.020 2.0 0 0.000 0.0
Negative (Not Specified) 
0         
 100 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
Test Chemical: Phenobarbital 
500         
 100 2 0.020 2.0 2 0.020 2.0 0 0.000 0.0 0 0.000 0.0 
1000         
 100 1 0.010 1.0 0 0.000 0.0 1 0.010 1.0 0 0.000 0.0 
2000         
 100 4 0.040 4.0 3 0.030 3.0 1 0.010 1.0 0 0.000 0.0 
3000         
 100 7 0.070 5.0 1 0.010 1.0 6 0.060 5.0 0 0.000 0.0
Positive Control: Cyclophosphamide 
50         
 100 58 0.580 39.0 37 0.370 28.0 21 0.210 17.0 0 0.000 0.0
Trend: 1.499 0.949 1.519  
Probability: 0.067 0.171 0.064  


Trial #:2   Activation: No Activation    Date: 01/27/1983    Harvest Time: 12 hour(s)   Trial Call: Weakly 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: Dimethyl Sulfoxide 
0         
 100 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
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
Test Chemical: Phenobarbital 
160         
 100 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0 0 0.000 0.0 
500         
 100 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0 0 0.000 0.0 
1600         
 100 4 0.040 3.0 3 0.030 2.0 1 0.010 1.0 0 0.000 0.0 
2000         
 100 5 0.050 5.0 2 0.020 2.0 3 0.030 3.0 0 0.000 0.0
Positive Control: Mitomycin-C 
 0.5       
 100 62 0.620 37.0 36 0.360 30.0 25 0.250 20.0 1 0.010 1.0
Trend: 2.564 1.469 2.234  
Probability: 0.005 0.071 0.013  


Trial #:2_S9   Activation: Induced Rat Liver S9    Date: 01/27/1983    Harvest Time: 12 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: Dimethyl Sulfoxide 
0         
 100 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0 0 0.000 0.0
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
Test Chemical: Phenobarbital 
50         
 100 3 0.030 3.0 1 0.010 1.0 0 0.000 0.0 2 0.020 2.0 
160         
 100 3 0.030 3.0 0 0.000 0.0 2 0.020 2.0 1 0.010 1.0 
500         
 100 7 0.070 7.0 3 0.030 3.0 0 0.000 0.0 4 0.040 4.0 
1600         
 100 5 0.050 5.0 2 0.020 2.0 2 0.020 2.0 1 0.010 1.0 
2000         
 100 5 0.050 5.0 3 0.030 3.0 1 0.010 1.0 1 0.010 1.0
Positive Control: Cyclophosphamide 
25         
 100 47 0.470 31.0 15 0.150 11.0 29 0.290 26.0 3 0.030 3.0
Cyclophosphamide 
50         
 100 69 0.690 45.0 44 0.440 30.0 22 0.220 19.0 3 0.030 3.0
Trend: 2.270 2.040 1.281  
Probability: 0.012 0.021 0.100