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: 002-03143-0001-0000-4
Chemical Name: o-Toluidine hydrochloride
CASRN: 636-21-5
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 867721_SCE
Study Result: Positive

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

Trial #: 1    Activation: No Activation    Date: 02/24/1983    Trial Call: Weakly 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 Dimethyl Sulfoxide 
0         
 50 1049 428 0.408 8.56 26.0 0.000
Test Chemical o-Toluidine hydrochloride 
50         
 50 1046 446 0.426 8.92 26.0 4.504 
160         
 50 1048 480 0.458 9.60 26.0 12.257 
500         
 50 1046 548 0.524 10.96 26.0 28.405
Positive Control Mitomycin-C 
 0.005     
 25 525 619 1.179 24.76 26.0 188.977
Trend: 4.069        
Probability: 0.000        

Trial #: 2    Activation: No Activation    Date: 05/05/1983    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 Dimethyl Sulfoxide 
0         
 50 1049 399 0.380 7.98 26.0 0.000
Test Chemical o-Toluidine hydrochloride 
500         
 50 1048 617 0.589 12.34 26.0 54.784 
600         
 50 1047 638 0.609 12.76 26.0 60.205 
700         
 50 1043 657 0.630 13.14 26.0 65.609
Positive Control Mitomycin-C 
 0.005     
 25 524 735 1.403 29.40 26.0 268.773
Trend: 7.522        
Probability: 0.000        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 02/24/1983    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 1049 461 0.439 9.22 26.0 0.000
Test Chemical o-Toluidine hydrochloride 
160         
 50 1048 433 0.413 8.66 26.0 -5.984 
500         
 50 1047 423 0.404 8.46 26.0 -8.068 
1600         
 50 1046 485 0.464 9.70 26.0 5.508
Positive Control Cyclophosphamide 
1         
 50 1047 826 0.789 16.52 26.0 79.518
Trend: 0.705        
Probability: 0.240