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Study Information
Study Attribute Value
CEBS Accession Number: 002-03007-0015-0000-8
Chemical Name: Water
CASRN: 7732-18-5
NTP Study Type: Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID: 488460
Study Result: Negative


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: Negative and Non-Toxic
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Fischer Medium 
 0         
 77 109 83 36 38
    72 102 94 44
    87 109 97 37
    68 80 74 36
Test Chemical Water 
312.5       
 74 77 90 41 45
    72 83 109 50
  
625         
 74 104 110 50 44
    84 97 98 39
  
1250         
 75 97 38 17 23
    86 99 75 29
  
2500         
 99 117 61 21 21
    89 99 57 21
  
5000         
 98 105 40 14 17
    80 101 50 21
Positive Control Methyl Methane Sulfonate 
15         
 42 35 242 191 223*
    31 30 234 256

Nonactivation Trial: 2 Experiment Call: Negative and Non-Toxic
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Fischer Medium 
 0         
 79 98 113 48 52
    79 105 115 48
    71 100 113 53
    65 97 112 58
Test Chemical Water 
2000         
 90 100 198 73 64
    81 84 134 55
  
3000         
 85 132 146 57 51
    87 114 115 44
  
4000         
 84 115 105 42 57
    78 79 171 73
  
5000         
 92 113 142 52 57
    83 99 154 62
Positive Control Methyl Methane Sulfonate 
15         
 23 22 216 315 336*
    29 16 307 357

Induced S9 Trial: 1 Experiment Call: Negative and Non-Toxic
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Fischer Medium 
 0         
 85 95 108 42 38
    101 98 86 29
    111 105 115 34
    95 101 133 47
Test Chemical Water 
1000         
 110 110 106 32 41
    74 93 111 50
  
2000         
 74 86 112 51 55
    98 94 177 60
  
3000         
 84 93 145 58 52
    75 94 102 45
  
4000         
 72 92 95 44 41
    83 95 96 39
  
5000         
 95 90 123 43 45
    88 93 126 48
Positive Control 3-Methylcholanthrene 
2.5       
 55 23 769 469 510*
    47 20 774 551

Induced S9 Trial: 2 Experiment Call: Negative and Non-Toxic
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Fischer Medium 
 0         
 97 107 87 30 31
    80 91 90 38
    79 99 64 27
    81 102 70 29
Test Chemical Water 
2000         
 100 104 63 21 28
    83 100 86 35
  
3000         
 77 100 63 27 33
    83 91 97 39
  
4000         
 64 82 40 21 22
    74 98 52 23
  
5000         
 75 83 37 17 21
    63 105 47 25
Positive Control 3-Methylcholanthrene 
2.5       
 59 35 435 246 260*
    57 23 464 274

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