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Study Information
Study Attribute Value
CEBS Accession Number: 002-02154-0013-0000-8
Chemical Name: Ethylbenzene
CASRN: 100-41-4
NTP Study Type: Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID: 746837
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.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Dimethyl Sulfoxide 
 0         
 87 92 138 53 60
    78 108 155 66
    89 106 150 56
    84 94 159 63
Test Chemical Ethylbenzene 
10         
 86 106 157 61 56
    81 103 123 51
  
20         
 81 90 130 54 53
    81 93 127 52
  
40         
 73 72 144 66 67
    87 82 175 67
  
80         
 71 32 1325 619 589*
    74 36 1235 559
  
160         
   
Positive Control Methyl Methane Sulfonate 
15         
 52 39 238 152 145*
    61 40 251 138
Methyl Methane Sulfonate 
250         
 83 95 374 150 149*
    81 85 357 147

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         
 100 101 91 30 31
    82 98 75 30
    69 95 63 30
    85 106 87 34
Test Chemical Ethylbenzene 
20         
 82 83 102 41 43
    83 83 109 44
  
40         
 73 54 58 27 29
    78 61 75 32
  
60         
 68 60 79 39 43
    64 37 91 48
  
80         
 55 15 233 142 150*
    48 10 228 159
  
100         
   
Positive Control Methyl Methane Sulfonate 
15         
 42 32 152 120 107*
    43 34 122 94
Methyl Methane Sulfonate 
250         
 50 67 302 201 225*
    51 67 381 250

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