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: 002-01073-0002-0000-5
Chemical Name: 1,3-Dichloro-5,5-dimethylhydantoin
CASRN: 118-52-5
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 807055_CA
Study Result: Negative

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

Trial #:1   Activation: No Activation    Date: 02/24/1982    Harvest Time: 14 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 4 0.040 4.0 1 0.010 1.0 3 0.030 3.0 0 0.000 0.0
Test Chemical: 1,3-Dichloro-5,5-dimethylhydantoin 
 0.5       
 100 4 0.040 4.0 0 0.000 0.0 4 0.040 4.0 0 0.000 0.0 
1.6       
 100 6 0.060 4.0 1 0.010 1.0 5 0.050 4.0 0 0.000 0.0 
5         
 100 4 0.040 4.0 0 0.000 0.0 4 0.040 4.0 0 0.000 0.0 
16         
 100 14 0.140 8.0 7 0.070 5.0 6 0.060 4.0 1 0.010 1.0
Positive Control: Mitomycin-C 
 0.15      
 100 38 0.380 25.0 10 0.100 10.0 28 0.280 20.0 0 0.000 0.0
Trend: 1.184 2.157 0.331  
Probability: 0.118 0.016 0.370  


Trial #:1_S9   Activation: Induced Rat Liver S9    Date: 06/10/1982    Harvest Time: 14 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 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0
Test Chemical: 1,3-Dichloro-5,5-dimethylhydantoin 
8         
 100 7 0.070 7.0 1 0.010 1.0 6 0.060 6.0 0 0.000 0.0 
12         
 100 10 0.100 7.0 2 0.020 2.0 8 0.080 6.0 0 0.000 0.0 
16         
 100 7 0.070 7.0 2 0.020 2.0 5 0.050 5.0 0 0.000 0.0
Positive Control: Cyclophosphamide 
15         
 100 25 0.250 22.0 9 0.090 9.0 16 0.160 14.0 0 0.000 0.0
Trend: 1.454 0.753 1.324  
Probability: 0.073 0.226 0.093  


Trial #:2_S9   Activation: Induced Rat Liver S9    Date: 02/24/1982    Harvest Time: 14 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 10 0.100 10.0 2 0.020 2.0 8 0.080 8.0 0 0.000 0.0
Test Chemical: 1,3-Dichloro-5,5-dimethylhydantoin 
1.6       
 100 5 0.050 5.0 0 0.000 0.0 5 0.050 5.0 0 0.000 0.0 
5         
 100 7 0.070 6.0 2 0.020 1.0 5 0.050 5.0 0 0.000 0.0 
16         
 100 12 0.120 10.0 4 0.040 4.0 8 0.080 7.0 0 0.000 0.0
Positive Control: Cyclophosphamide 
15         
 100 12 0.120 12.0 3 0.030 3.0 9 0.090 9.0 0 0.000 0.0
Trend: 0.087 1.198 -0.275  
Probability: 0.465 0.116 0.608