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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1/30/86 - 2/26/86
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Test procedure in accordance with national standard methods

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1986

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: Ames-114, Editon 4
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): tetrafluoroethylene
- Substance type: pure active substance
- Physical state: gas
- Analytical purity: 99.12
- Impurities (identity and concentrations): 0.88% octafluorocyclobutane
- Composition of test material, percentage of components:
- Lot/batch No.: 10223
- Stability under test conditions: The test material was determined to be stable throughout the exposure phase of the study. The sample analysis were performed at Haskell Laboratory.

Method

Species / strain
Species / strain / cell type:
other: TA 1537, TA 1535, TA 100, TA98 and TA 97
Metabolic activation:
with and without
Metabolic activation system:
S9
Test concentrations with justification for top dose:
0, 0.5, 3, 4 or 5%
Vehicle / solvent:
air; control air.
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Remarks:
2-amino anthracene (2-AA); N-methyl-N'-nitroso-N-nitroguanidine (MNNG); 2-Nitrofluorene (2-NF); for strains TA1535 and TA100 vinyl chloride (VC)
Positive control substance:
other: 2-aminoanthracene, 9-aminoacridine, N-methyl-N'-nitrosoguanidine, 2-nitrofluorene. The solvent used for these positive indicators was DMSO. For strains TA1535 and TA100, vinyl chloride mixed with air was used in activated treatments.
Details on test system and experimental conditions:
48 hours exposure
Evaluation criteria:
Classification:
A test sample is classified as POSITIVE when:

a) The number of induced revertants at one or more of the test sample concentrations are at least two times greater than the nunber of revertants in the solven control. The dose levels must have a probability of less than 0.01 that the number of induced revertants are the same as the spontaneous revertant number.

And

b) The probability is less than 0.01 that there is not a positive correlation between the number of revertants and increasing concentrations of the test sample.

A test sample is classified as NEGATIVE when:

a) The probability is greater than 0.05 that the numbers of revertants at each of the test sample concentrations studies are not greater than the number of revertants in the solvent control.

And

b) The probability is greater than 0.05 that there is not a positive correlation between the numbers of revertants and increasing concentrations of the test sample.

A test sample is classified as EQUIVOCAL when:

a) neither the criteria for a positve or negative are satisfied.
Statistics:
Individual sets of data consisting of two acceptable trials performed in each strain with or without activation were analysed according to the statistical method of R.D. Snee and J.D Irr (Mutation Research 128: 115-125, 1984). The power transformation for this assay was established as 0.20. The probability values were determined on the transformed data based on the analysis of Dunnet (Dunlap, W.P. , Marx, M.S., and G.J. Agamy Behavioural Research Methods and Instrumentation 13:363-366, 1981).

Results and discussion

Test results
Species / strain:
other: S. typhimurium strains TA1535, TA97, TA98 and TA100
Metabolic activation:
with and without
Genotoxicity:
negative
Vehicle controls validity:
valid
Positive controls validity:
valid
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

In the cytoxicity assessment with strain TA 98 (Table 1) TFE was evaluated up to an approximate concentration of 5.0% (5.5% measured). This maximum concentration (1/2 the lower flammability limit of TFE in air) was chosen to avoid possible safety hazards. Based on the cytotoxicity results, mutagenicity testing, both with and without metabolic activation, was conducted at approximate concentrations of 1, 3, 4 and 5 %.The mutagenicity data obtained from strains TA1535, TA97, TA98 and TA100 are presented in Tables 2 - 5 repectively. Actual measured concentrations, as reported in the tables, ranged from 0.5 to 4.8% TFE. No significant increases in revertants or positive linear dose-responses were seen in any of the strains. Under the conditions of this assay TFE was negative.

Table 1: Genotoxicity in Salmonella Typhimurium Strain TA98

 Compound Concentration   Without Activation With Activation  
  Colonies / Plate (duplicate Plates)a  Colonies /Plate (duplicate Plates) 
TFE  0 (control)  32, 22   1038, 1156
 '' 1.6  18, 5  938, 985 
 '' 3.4  23, 36  1248, 1182
''  4.3   21, 6 1043, 1180 
''  5.5   34, 36  1101, 1065

a Non-activated results were unexplainably low. However, due to a limited supply of TFE, the mutagenicity trials proceded tested up to the maximal allowed concentration of 5% (estimated) of TFE.

Table 2: Mutagenic Activity of TFE in Salmonella Typhimurium Strain TA1535

 Compound  Concentration           Revertants per Plate (Duplicate Plates)
   % Without Activation     With Activation    
     Trial 1  Trial 2  Trial 1  Trial 2
 TFE  0 (Control) 22, 25  20, 27  19, 23  20, 19 
 ''   0.49 +/- 0.02  --, -- 26,21     
 ''   0.82 +/- 0.03 22, 26   --, --  19, 25 --, -- 
 ''   0.92 +/- 0.02  --, -- 27, 21   --, -- 17, 21 
 ''   1.39 +/- 0.02  34, 35  --, --  18, 16 --, -- 
 ''   2.04 +/- 0.05  --, --  26, 29  --, -- 23, 26 
''   2.79 +/- 0.10 --, --  21, 36   --, -- 25, 26
 ''   2.87 +/- 0.00 28, 33  --, --   15, 13 --, -- 
 ''   3.17 +/- 0.02  --, --  27, 30  --, -- 29, 26 
 ''   3.69 +/- 0.13  33, 27  --, -- 13, 14   --, --
 ''   4.82 +/- 0.02  29, 29  --, --  4, 19 --, -- 
 MNNG  4 (ug/plate)  2372, 2551 3630,2592   
 VC  1.5a     99, 128  --, -- 
   2.2a      --, --  115, 79

aonly one chamber was used for VC exposure

Table 3: Mutagenic Activity of TFE in Salmonella Typhimurium Strain TA97

 Compound

 Concentration

          Revertants per Plate (Duplicate Plates)

 

 %

    Without Activation

 With Activation   

 

 

 Trial 1

 Trial 2

 Trial 1

 Trial 2

 TFE

 0 (Control)

143, 159 

 146, 144

 182, 197

 190, 171

 ''

  0.49 +/- 0.02

 --, --

 147, 156

 --, --

 187, 168

 ''

  0.82 +/- 0.03

162, 157 

 --, --

 215, 196

 --, --

 ''

  0.92 +/- 0.02

--, -- 

 157, 147

 --, --

 156, 159

 ''

  1.39 +/- 0.02

 156, 142

 --, --

 166, 198

 --,--

 ''

  2.04 +/- 0.05

--, --

 140, 129

 --. --

 168, 146

''

  2.79 +/- 0.10

--, -- 

116, 119 

--, -- 

 175, 197

 ''

  2.87 +/- 0.00

 135, 142

 --, --

 198, 186

 --, --

 ''

  3.17 +/- 0.02

 --, --

 134, 142

 --, --

 155, 172

 ''

  3.69 +/- 0.13

 144, 151

 --, --

 191, 174

 --, --

 ''

  4.82 +/- 0.02

147, 129 

 --, --

 183, 205

 --, --

 9 -AAc

 50 (ug/plate)

918 , 512

630, 409 

 

 

 2AA

 1 (ug/plate)

 

 

998, 1154 

988, 889 

 

 

 

 

 

 

Table 4: Mutagenic Activity of TFE in Salmonella Typhimurium Strain TA98

 Compound

 Concentration

          Revertants per Plate (Duplicate Plates)

 

 %

Without Activation    

 With Activation   

 

 

 Trial 1

 Trial 2

 Trial 1

 Trial 2

 TFE

 0 (Control)

18, 26 

 16, 19

 34, 35

 27, 29

 ''

  0.49 +/- 0.02

--, -- 

 19, 23

 --, --

 35, 27

 ''

  0.82 +/- 0.03

20, 24 

 --, --

 28, 31

 --, --

 ''

  0.92 +/- 0.02

--, -- 

 12, 20

 --, --

 29, 40

 ''

  1.39 +/- 0.02

16, 20 

 --, --

 33, 34

 --, --

 ''

  2.04 +/- 0.05

--, -- 

 15, 20

 --, --

 26, 29

''

  2.79 +/- 0.10

--, -- 

 17, 11

 --, --

 26, 26

 ''

  2.87 +/- 0.00

 21, 14

 --, --

 26, 27

 --, --

 ''

  3.17 +/- 0.02

 --, --

 18, 15

 --, --

 25, 26

 ''

  3.69 +/- 0.13

20, 15 

 --, --

 28, 30

 --, --

 ''

  4.82 +/- 0.02

17, 23 

 --, --

 23, 30

--, -- 

 2 -NF

25 (ug/plate)

2529, 2347 

 1934, 2271

 

 

2 -AA

2

 

 

1868, 2661 

3332, 3084 

 

 

 

 

 

 

Table 5: Mutagenic Activity of TFE in Salmonella Typhimurium Strain TA100

 Compound

 Concentration

          Revertants per Plate (Duplicate Plates)

 

 %

    

    

 

 

 Trial 1

 Trial 2

 Trial 1

 Trial 2

 TFE

 0 (Control)

168, 142 

 174, 163

 141, 138

 109, 132

 ''

  0.49 +/- 0.02

 --, --

142, 128 

 --, --

 148, 117

 ''

  0.82 +/- 0.03

135, 163 

 --, --

 130, 133

 --, --

 ''

  0.92 +/- 0.02

--, -- 

 126, 117

--, -- 

 115, 129

 ''

  1.39 +/- 0.02

 118, 130

 --, --

 129, 125

 --, --

 ''

  2.04 +/- 0.05

--, -- 

 148, 161

 --, --

 135, 140

''

  2.79 +/- 0.10

--, -- 

 114, 133

 --, --

147, 145 

 ''

  2.87 +/- 0.00

 149, 170

 --, --

 132, 127

 --, --

 ''

  3.17 +/- 0.02

--, -- 

140, 131 

--, -- 

 134, 131

 ''

  3.69 +/- 0.13

 130, 103

 --, --

 132, 129

 --, --

 ''

  4.82 +/- 0.02

 131, 135

 --, --

 146, 140

 --, --

 MNNG

 4 (ug/plate)

 3396, 3238

 3536, 2780

 

 

 VC

 1.5a

 

 

308, 295 

 --, --

 

 2.2a

 

 

--, -- 

315, 322 

a only one chamber was used for VC exposure

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

TFE was not mutagenic in the Ames bacterial reverse mutation assay using Salmonella typhimurium strains TA1535, TA97, TA98 and TA 100, both inthe presence and absence of metabolic activation.
Executive summary:

Tetrafluoroethylene (TFE) was tested for mutagenic activity in Salmonella typhimurium strains TA 1535, TA97, TA98 and TA100 in the presence and absence of a metabolic activation system (S9 Aroclor-treated rat liver homogenate) . Under the conditions of this assay, TFE was negative with or without metabolic activation.