Government Funding Lapse

Because of a lapse in government funding, the information on this website may not be up to date, transactions submitted via the website may not be processed, and the agency may not be able to respond to inquiries until appropriations are enacted. The NIH Clinical Center (the research hospital of NIH) is open. For more details about its operating status, please visit  cc.nih.gov. Updates regarding government operating status and resumption of normal operations can be found at opm.gov.

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.

Study Information
Study Attribute Value
CEBS Accession Number: 002-01873-0009-0000-0
Chemical Name: Chlorothalonil
CASRN: 1897-45-6
NTP Study Type: Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID: 351015
Study Result: Positive


Table Instructions and Notes:
Studies are indicated to be "Nontoxic" when the observed reductions in relative total growth did not indicate that the maximum tolerated dose was achieved.

Nonactivation Trial: 1 Experiment Call: Inconclusive
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 76 97 165 73 77
    52 88 128 82
    74 107 173 78
    66 107 150 75
Test Chemical Chlorothalonil 
 0.01      
 71 95 197 92 80
    64 98 131 68
  
 0.02      
 52 84 133 85 84
    46 74 113 83
  
 0.04      
 57 87 106 62 61
    70 91 128 61
  
 0.08      
 61 71 155 85 83
    62 78 148 80
  
 0.16      
 58 66 171 99 101
    44# 50 136.5 103
  
 0.32      
   
Positive Control Methyl Methane Sulfonate 
15         
 18# 15 346.5 648 670*
    19 14 388 693

Nonactivation Trial: 2 Experiment Call: Positive
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 68 92 88 43 35
    83 107 69 28
    84 94 73 29
    83 107 104 42
Test Chemical Chlorothalonil 
 0.0075    
 79 89 90 38 37
    92 91 98 36
  
 0.015     
 96 95 107 37 44
    70 77 105 50
  
 0.03      
 71 86 80 38 35
    101 88 98 32
  
 0.06      
 98 82 114 39 35
    91 97 84 31
  
 0.12      
 68 41 212 103 91*
    77 43 184 79
  
 0.24      
   
Positive Control Methyl Methane Sulfonate 
15         
 47 30 181 129 128*
    45 32 170 126

Nonactivation Trial: 3 Experiment Call: Positive
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 69 96 137 66 73
    65 91 147 75
    81 94 188 77
    81 118 179 73
Test Chemical Chlorothalonil 
 0.025     
 70 97 158 76 78
    79 92 188 79
  
 0.05      
 65 88 176 90 93
    74 88 215 97
  
 0.1       
 68 95 152 75 77
    85 90 202 80
  
 0.15      
 86 76 223 86 102
    63 53 221 118
  
 0.2       
 67 30 361 179 187*
    69 37 406 195
  
 0.25      
   
Positive Control Methyl Methane Sulfonate 
15         
 53 39 258 161 160*
    59 40 281 158

Footnotes:
Asterisks(*) indicate significant responses.
r = rejected value due to quality control criteria
# = reduced sample size because of the loss of one culture dish due to contamination