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Study Information
Study Attribute Value
CEBS Accession Number: 002-02792-0005-0000-7
Chemical Name: Safrole
CASRN: 94-59-7
NTP Study Type: Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID: 271390
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: Positive
  Conc.
uL/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 79 96 69 29 26
    85 91 72 28
    69 97 50 24
    74 116 50 23
Test Chemical Safrole 
 0.036     
 73 141 132 60 52*
    76 87 98 43
  
 0.045     
 72 79 75 35 47*
    67 68 121 60
  
 0.056     
 77 81 93 40 33
    83 87 65 26
  
 0.071     
 71 67 79 37 35
    80 74 79 33
  
 0.088     
 85 73 102 40 36
    72 53 69 32
  
 0.11      
 75 24 569 253 334*
    50 15 623 415
  
 0.138     
   
Positive Control Ethyl Methane Sulfonate 
500         
 39 23 1147 976 855*
    41 23 1078 876
    51 35 1091 713

Nonactivation Trial: 2 Experiment Call: Negative
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 76 109 94 41 48
    81 95 104 43
    83 100 134 54
    76 96 125 55
Test Chemical Safrole 
 0.05      
 69 49 100 48 47
    74 49 104 47
  
 0.06      
 59 38 94 53 45
    60 34 65 36
  
 0.08      
 40 8 25 21 33
    42 8 56 45
  
 0.09      
   
Positive Control Ethyl Methane Sulfonate 
500         
 35 25 661 630 663*
    38 33 738 642
    29 22 631 717

Nonactivation Trial: 3 Experiment Call: Rejected
  Conc.
uL/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 70 102 30 14 13
    74 103 36 16
    64 92 21 11
    68 103 22 11
Test Chemical Safrole 
 0.025     
 48 78 37 26 19
    56 87 18 11
    43 60 26 20
  
 0.031     
 45 54 58 43 29*
    39 49 28 24
    54 82 34 21
  
 0.039     
 40 51 49 41 31*
    63 84 29 15
    56 80 63 38
  
 0.049     
 64 85 18 9 15
    71 108 43 20
  
 0.061     
 65 74 50 26 26*
    49 59 36 25
    55 64 44 27
  
 0.077     
 69 73 40 19 25*
    52 55 59 38
    76 85 38 17
  
 0.096     
 43 15 13 10 24
    37 9 42 38
   
  
 0.12      
   
   
Positive Control Ethyl Methane Sulfonate 
500         
 51 61 599 395 377*
    53 62 549 344
    50 50 583 393

Induced S9 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         
 73 94 146 67 57
    79 96 109 46
    91 110 154 57
Test Chemical Safrole 
 0.002     
 81 97 88 36 39
    63 68 79 42
  
 0.005     
 78 98 165 71 58
    86 101 117 46
  
 0.01      
 106 88 126 40 43
    88 88 123 47
  
 0.02      
 81 70 85 35 33
    60 50 57 32
Positive Control 3-Methylcholanthrene 
5         
 35 19 395 382 349*
    36 21 362 340
    34 20 327 325

Induced S9 Trial: 2 Experiment Call: Positive
  Conc.
uL/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 92 107 86 31 33
    85 99 64 25
    89 100 102 38
    79 95 89 38
Test Chemical Safrole 
 0.015     
 47 5 114 81 72*
    70 53 134 64
    73 51 153 70
  
 0.018     
 77 32 148 64 71*
    81 61 198 82
    83 52 164 66
  
 0.023     
 79# 49 168 71 78*
    81 52 172 71
    76 41 208 91
  
 0.029     
 78# 42 160.5 69 65*
    85 51 157 62
  
 0.036     
 76 42 164 72 66*
    73 44 154 71
    79 44 132 56
Positive Control 3-Methylcholanthrene 
5         
 35 22 426 404 379*
    39 24 426 369
    34 15 373 364

Induced S9 Trial: 3 Experiment Call: Positive
  Conc.
uL/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 107 107 136 42 46
    94 108 126 45
    90 91 126 47
    90 94 137 51
Test Chemical Safrole 
 0.005     
 88 76 195 74 81*
    77 59 181 79
    82 61 220 89
  
 0.01      
 62 26 228 123 119*
    79 35 253 107
    72 32 278 128
  
 0.02      
 32 6 202 213 233*
    51 9 385 252
    50 8 349 233
  
 0.03      
 20 2 207 354 366*
    20 2 220 364
    18 2 206 381
  
 0.04      
   
   
Positive Control 3-Methylcholanthrene 
5         
 50 27 407 272 273*
    57 32 454 266
    53 32 445 279

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