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Study Information
Study Attribute Value
CEBS Accession Number: 002-01017-0016-0000-8
Chemical Name: 1,1,2,2-Tetrachloroethane
CASRN: 79-34-5
NTP Study Type: Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID: 990809
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
  Conc.
ug/mL
Cloning
Efficiency
Relative Total
Growth
Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Ethanol
 0         
73 92 85 39 31
    96 114 93 32
    94 89 71 25
    94 106 79 28
Test Chemical 1,1,2,2-Tetrachloroethane
60         
76 14 88 39 37
    84 30 105 42
    97# 48 86 30
 
80         
99 30 84 28 45
    54 21 101 63
    60# 21 79 44
 
100         
106 33 68 21 34
    67 19 80 40
    78 25 98 42
 
120         
87 26 103 40 43
    64 21 88 46
    83 23 110 44
 
150         
63 13 100 53 51*
    58 10 86 49
    61 20 94 51
 
200         
41# 9 57 46 41
    85 18 121 47
    93 19 86 31
Positive Control Methyl Methane Sulfonate
5         
54 35 691 429 458*
    43 24 629 486
    38 12 518 458

Nonactivation Trial: 2 Experiment Call: Negative
  Conc.
ug/mL
Cloning
Efficiency
Relative Total
Growth
Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Ethanol
 0         
179r 128 81 15 15
    112 108 51 15
    159r 98 50 11
    112 92 53 16
Test Chemical 1,1,2,2-Tetrachloroethane
25         
74 63 35 16 16
    63 53 33 18
    76 54 34 15
 
50         
50 26 25 17 19
    53 28 42 26
    58 38 24 14
 
75         
64 31 38 20 21
    68 25 37 18
    59 22 45 25
 
100         
68 16 48 23 21
    72 24 40 19
    63 26 42 22
 
150         
67 17 40 20 19
    60 18 39 22
    59 17 30 17
 
200         
75 7 22 10 9
    71 6 14 7
    73 8 22 10
 
300         
   
   
Positive Control Methyl Methane Sulfonate
5         
74 33 266 119 135*
    56 30 229 136
    69 31 311 151

Induced S9 Trial: 1 Experiment Call: Inconclusive
  Conc.
ug/mL
Cloning
Efficiency
Relative Total
Growth
Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Ethanol
 0         
117 113 107 31 28
    117 129 70 20
    104 70 92 29
    110 88 99 30
Test Chemical 1,1,2,2-Tetrachloroethane
50         
111 99 131 39 34
    95 88 110 38
    101 110 72 24
 
75         
102 66 102 33 33
    106# 83 113 36
    116 102 108 31
 
100         
103 49 119 38 40
    86# 94 90 35
    69 73 98 47
 
150         
114 87 98 29 32
    98 77 79 27
    93 68 109 39
 
200         
94 65 76 27 24
    115 108 56 16
    79 52 72 30
 
300         
111 104 68 20 24
    107 107 68 21
    108 112 94 29
Positive Control 3-Methylcholanthrene
2.5       
117 35 877 251 280*
    38 3 416 368
    98 25 655 222

Induced S9 Trial: 2 Experiment Call: Negative
  Conc.
ug/mL
Cloning
Efficiency
Relative Total
Growth
Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Ethanol
 0         
107 111 184 57 44
    100 68 67 22
    89 121 119 45
    110 100 172 52
Test Chemical 1,1,2,2-Tetrachloroethane
50         
87 74 226 87 60
    94 63 164 58
    116 78 123 35
 
75         
108 62 115 36 50
    91 93 163 60
    113 102 187 55
 
100         
100 65 188 63 59
    86 35 157 61
    106 79 167 53
 
150         
115 76 118 34 35
    89 57 128 48
    97 56 62 21
 
200         
113 31 95 28 28
    115 26 91 26
    104 55 90 29
 
300         
30
    107 11 76 24
    111 11 123 37
 
500         
   
   
Positive Control 3-Methylcholanthrene
2.5       
46 7 666 479 513*
    51 18 824 537
    28 4 438 525

Induced S9 Trial: 3 Experiment Call: Negative
  Conc.
ug/mL
Cloning
Efficiency
Relative Total
Growth
Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Ethanol
 0         
37
    114 136 121 35
    105 101 136 43
    105 63 107 34
Test Chemical 1,1,2,2-Tetrachloroethane
50         
104 17 94 30 31
    103 91 122 39
    107 69 79 25
 
75         
106 76 109 34 31
    100 13 84 28
   
 
100         
99 64 95 32 31
    110 73 94 28
    107 69 109 34
 
150         
124r 50 104 28
    111 71 114 34
   
 
200         
102 23 106 35 31
   
    112 65 91 27
 
300         
   
   
Positive Control 3-Methylcholanthrene
2.5       
269*
    86 24 663 258
    114 46 960 281

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