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Study Information
Study Attribute Value
CEBS Accession Number: 002-03187-0008-0000-9
Chemical Name: p-Phenylenediamine dihydrochloride
CASRN: 624-18-0
NTP Study Type: Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID: G39584
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: Negative
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 89 103 82 31 32
    84 97 83 33
Test Chemical p-Phenylenediamine dihydrochloride 
2.1       
 98 133 131 45 39
    93 126 94 34
  
2.6       
 99 114 87 29 38
    93 93 130 47
  
3.3       
 80 62 62 26 32
    78 64 89 38
  
4.1       
  
5.1       
 68 18 72 35 33
    72 20 66 31
  
6.4       
 73 7 36 16 16
    63 6 31 16
  
8         
   
Positive Control Ethyl Methane Sulfonate 
500         
 58 39 725 420 420*

Nonactivation Trial: 2 Experiment Call: Positive
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Water 
 0         
 104 127 146 47 54
    93# 88 147 53
    85 76 132 52
    98 108 187 64
Test Chemical p-Phenylenediamine dihydrochloride 
2.1       
 100 95 177 59 52
    98 71 152 52
    115 134 158 46
  
2.62      
 110 68 186 56 75
    91 45 235 87
    89 42 216 81
  
3.28      
 102 25 228 75 80*
    70 16 205 97
    83 18 171 69
  
4.1       
 64 5 195 102 109*
    67 5 257 129
    71 5 205 97
  
5.12      
   
   
Positive Control Ethyl Methane Sulfonate 
500         
 74 68 953 428 513*
    67# 51 1116 555
    71 52 1177 555

Nonactivation Trial: 3 Experiment Call: Positive
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Water 
 0         
 96 121 160 55 43
    96 110 124 43
    73 83 80 36
    87 87 94 36
Test Chemical p-Phenylenediamine dihydrochloride 
2.1       
 122r 128 154 42
    77# 78 138 59
  
2.7       
 87 91 91 35 50
    108 179 212 66
    139r 144 166.5 40
  
3.3       
 47 40 103 74
    159r 146 268.5 56
  
4.2       
 69 65 124 60 61
    73# 57 135 62
  
5.2       
 62 37 170 91 92*
    82 50 230 93
  
6.5       
 93 24 258 93 133*
    56 13 238 142
    64 12 316 166
Positive Control Ethyl Methane Sulfonate 
500         
 79 60 566 240 261*
    72 54 573 267
    72 44 593 276

Induced S9 Trial: 1 Experiment Call: Positive
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Water 
 0         
 84 100 190 76 60
    85 113 114 45
    64 87 111 58
Test Chemical p-Phenylenediamine dihydrochloride 
7         
 90 127 106 39 44
    114 141 166 49
  
11.7       
 106 114 155 49 47
    112 151 150 45
  
19.4       
 89 89 199 75 62
    104 89 156 50
  
32.4       
 73 36 177 80 82
    96 52 239 83
  
54         
 68 30 176 86 89
    70 35 194 93
  
90         
 71 26 195 92 93
    71 28 200 94
  
150         
 63 22 153 81 75
    76 23 160 70
  
250         
 62 19 194 104 114*
    62 18 229 123
Positive Control 3-Methylcholanthrene 
5         
 44 30 413 314 338*
    41 24 436 357
    38 26 394 343

Induced S9 Trial: 2 Experiment Call: Negative
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Water 
 0         
 89 94 170 64 64
    87 98 147 57
    73 96 154 70
    97 112 189 65
Test Chemical p-Phenylenediamine dihydrochloride 
7         
 92 106 156 57 54
    104 103 162 52
  
11.7       
 89 81 185 69 58
    93 94 129 46
  
19.4       
 83 52 202 81 68
    90 67 148 55
  
32.4       
 63 35 164 87 79
    67 35 141 70
  
54         
 55 22 142 86 74
    62 23 117 63
  
90         
 70 25 118 56 63
    68 19 144 70
  
150         
 79 22 160 68 72
    68 18 153 76
  
250         
 77 18 185 80 77
    66 16 146 73
Positive Control 3-Methylcholanthrene 
5         
 42 21 458 366 396*
    37 15 451 410
    39 18 484 412

Induced S9 Trial: 3 Experiment Call: Positive
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Water 
 0         
 87 107 160 61 56
    91 97 149 55
    88 98 146 55
    96 98 147 51
Test Chemical p-Phenylenediamine dihydrochloride 
33.2       
 111 73 265 80 84*
    82# 52 237 96
    98 62 223 76
  
55.3       
 100 47 218 73 70
    88 36 200 76
    95 38 180 63
  
92.2       
 98 40 212 72 76
    94 38 253 90
    91 42 178 65
  
154         
 72 27 209 97 77
    105 42 169 54
    78 35 190 82
  
192         
 78 27 256 109 94*
    82 26 179 73
    76 25 230 101
  
240         
 68 24 224 110 111*
    57 20 209 122
    71 16 219 103
  
300         
 57 21 163 96 103*
    73 22 242 110
    75 23 227 101
Positive Control 3-Methylcholanthrene 
5         
 67 66 528 262 236*
    100 70 624 208
    75 66 538 239

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