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Study Information
Study Attribute Value
CEBS Accession Number: 002-02674-0002-0000-3
Chemical Name: Phenoxy acetic acid
CASRN: 122-59-8
NTP Study Type: Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID: 869769
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 Ethanol 
 0         
 84 109 63 25 32
    75 96 75 33
    81 102 69 29
    87 93 106 41
Test Chemical Phenoxy acetic acid 
125         
 74 86 69 31 26
    86 81 50 19
    90 75 75 28
  
250         
 91 107 79 29 28
    73 77 66 30
    97 97 70 24
  
500         
 100 89 75 25 27
    65 75 65 33
    74 84 50 23
  
750         
 85 78 106 41 39
    289r 265 128 15
    91 66 99 36
  
1000         
 75 73 63 28 33
    64 58 92 48
    71 72 48 23
  
1500         
 74*
    45 7 151 111
    66 51 72 37
  
2000         
   
   
Positive Control Methyl Methane Sulfonate 
5         
 74 85 402 181 179*
    79 83 453 191
    83 73 413 166

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 Ethanol 
 0         
 129r 101 60 15 22
    107# 101 76 24
    105# 99 66 21
Test Chemical Phenoxy acetic acid 
125         
 133r 76 49 12
    128r 82 40 10
    129r 96 68 18
  
250         
 101 82 61 20 16
    111 69 38 11
    149r 93 48 11
  
500         
 138r 92 63 15
    112 81 53 16
    127r 78 50 13
  
750         
 141r 83 47 11
    128r 82 59 15
    157r 89 63 13
  
1000         
 181r 74 72 13
    148r 78 56 13
    130r 54 63 16
Positive Control Methyl Methane Sulfonate 
5         
 67 26 349 174 146*
    70 39 255 122
    76 30 324 141

Nonactivation Trial: 3 Experiment Call: Negative and Non-Toxic
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Ethanol 
 0         
 124r 100 109 29 28
    126r 92 120 32
    117 97 93 26
    97 103 86 30
Test Chemical Phenoxy acetic acid 
62.5       
 93 75 72 26 29
    123r 85 71 19
    95 68 90 32
  
125         
 108 67 80 25 25
    98 80 66 23
    99 65 82 28
  
250         
 103 77 85 28 26
    107 68 74 23
    107 71 91 28
  
500         
 115 55 105 30 32
    118 61 116 33
    122r 67 100 27
  
750         
 108 59 77 24 27
    108 44 103 32
    120 63 94 26
  
1000         
 106 42 123 39 39
    92 39 122 44
    105 48 107 34
Positive Control Methyl Methane Sulfonate 
5         
 49 27 502 345 435*
    53 24 800 505
    56 32 762 455

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 Ethanol 
 0         
 93 109 156 56 48
    82 89 135 55
    80 89 95 40
    90 113 110 41
Test Chemical Phenoxy acetic acid 
125         
 102# 91 119 39 41
    98 87 147 50
    85 71 90 35
  
250         
 107# 119 77 24 33
    81 91 98 40
    105# 88 112 35
  
500         
 90 88 107 39 37
    96# 94 100 35
    101 91 113 37
  
750         
 110 103 180 55 49
    88 69 110 42
    96 80 146 51
  
1000         
 103 71 136 44 53
    86# 79 135 52
    72 61 137 63
  
1500         
 108 65 109 34 23
    95 58 26 9
    84 65 65 26
  
2000         
   
   
Positive Control 3-Methylcholanthrene 
2.5       
 43 22 625 484 401*
    60 25 753 418
    81 39 729 299

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 Ethanol 
 0         
 106 106 145 46 49
    99 115 131 44
    87 79 136 52
    84 101 134 53
Test Chemical Phenoxy acetic acid 
125         
 123r 97 177 48
    120r 94 141 39
    133r 86 183 46
  
250         
 119 89 118 33 43
    91 59 139 51
    98 57 132 45
  
500         
 123r 78 193 52 48
    94# 79 148 52
    113 87 150 44
  
750         
 108 77 137 42 48
    108 76 144 44
    95 72 164 57
  
1000         
 103 78 42 14 33
    103 92 131 43
    113 88 146 43
  
1500         
 145r 58 173 40 61
    105 68 157 50
    101 29 216 71
Positive Control 3-Methylcholanthrene 
2.5       
 68 22 973 475 424*
    64 27 855 443
    83 28 881 355

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