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Study Information
Study Attribute Value
CEBS Accession Number: 002-02434-0014-0000-0
Chemical Name: Methyl ethyl ketone peroxide
CASRN: 1338-23-4
NTP Study Type: Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID: 091264
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:
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Ethanol 
 0         
 78# 113 71 31 32
    65 103 69 35
    50 57 44 29
    104 128 100 32
Test Chemical Methyl ethyl ketone peroxide 
2         
 39 38 111 94 87*
    40 44 123 103
    72 60 136 63
  
3         
 35 40 88 83 78*
    29 25 88 99
    57 51 88 52
  
4         
 61 60 385 211 190*
    46 32 273 200
    30# 39 143 158
  
6         
 70 75 319 152 182*
    66# 38 390 197
    39 55 229 198
  
8         
 59 19 396 223 223*
    61 34 408 222
  
10         
 65 23 495 254 222*
    84 29 481 191
Positive Control Methyl Methane Sulfonate 
5         
 52 59 448 284 266*
    57 41 505 295
    63 66 417 219

Nonactivation Trial: 2 Experiment Call: Positive
  Conc.
ug/mL 		Cloning
Efficiency 		Relative Total
Growth 		Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Ethanol 
 0         
 85 88 132 52 43
    95 98 127 45
    130r 103 130 33
    118 114 118 33
Test Chemical Methyl ethyl ketone peroxide 
 0.625     
 84 88 84 33 32
    85 81 81 32
    113# 98 106 31
  
1.25      
 91 100 98 36 36
    107 92 106 33
    91 99 108 39
  
2.5       
 97# 86 108 37 69*
    91 58 266 97
    85 65 182 71
  
5         
 73 35 481 221 170*
    75 36 227 101
    75 41 424 188
  
7.5       
 79# 31 544 230 267*
    86 23 776 300
    93 27 761 272
  
10         
 74 23 616 279 306*
    75 16 740 327
    74 12 696 313
Positive Control Methyl Methane Sulfonate 
5         
 84 69 601 238 256*
    81# 63 604 250
    76 62 640 279

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