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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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study according to OECD Guideline 471/472 with GLP. Study in Japanese with complete English translation.
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2000

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Version / remarks:
& OECD Guideline 472 (Genetic Toxicology: Escherichia coli, Reverse Mutation Assay)
Principles of method if other than guideline:
Guidelines for Screening Mutagenicity Testing of Chemicals (Chemical Substances Control Law of Japan)
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): dicumyl peroxide
- Molecular formula (if other than submission substance): C18H22O2
- Substance type: white solid (flake form)
- Physical state: solid
- Analytical purity: 99.9%
- Lot/batch No.: 8X04
- Stability under test conditions: stable at normal temperature

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
E. coli WP2 uvr A
Metabolic activation:
with and without
Metabolic activation system:
S9 mix from rat liver, induced with phenobarbital and 5,6-benzoflavon
Test concentrations with justification for top dose:
cytotoxicity: 50, 150, 500, 1500, 5000 µg/plate
mutagenicity: 313, 625, 1250, 2500, 5000 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: Dimethyl sulfoxide
Controls
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
other: -S9 mix; 2-(2-Furyl)-3-(5-nitro-2-furyl)acrylamide (TA100, TA98, WP2 uvrA), Sodium azide (TA1535) and 9-Aminoacridine (TA1537) +S9 mix; 2-Aminoanthracene (five strains)
Details on test system and experimental conditions:
Pre-incubation method
Evaluation criteria:
The results were judged to be positive when the mean number of revertant colonies for each dose of the test article was increased twice or more than that in the negative control and when dose dependency or reproducibility was observed in the increase of revertant colonies, in at least one strain out of the five strains used with or without S9 mix.

Results and discussion

Test results
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not specified
Positive controls validity:
valid
Additional information on results:
The number of revertant colonies was not increased twice or more than that in the negative control in any strain used with or without S9 mix in the two mutagenicity tests.
In all tests, microbial contamination was not detected in the dosing formulation of the highest concentration or S9 mix. Furthermore, positive results were confirmed in the positive control groups, and the mean numbers of revertant colonies in the positive and negative controls were within the fluctuation range (mean ± 3 S.D.) of the historical control values in all strains. Thus, the validity of this test system was confirmed.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Mutagenicity of dicumyl peroxide on bacteria (I)

 

 

 

 

No colonies/plate

 

 

+/- S9mix

DCP (µg/plate)

TA100

Ta1535

WP2 uvrA

TA98

TA1537

-

0

163+-2.1

12+-1.5

19+-4.7

27+-4.0

12+-4.0

-

313

158+-15.6

9+-1.7

25+-5.1

21+-4.2

10+-3.2

-

625

131+-9.2

20+-2.0

20+-2.0

15+-1.0

9+-4.9

-

1250

157+-20.0

18+-2.0

18+-2.0

18+-4.5

7+-1.5

-

2500

156+-8.0

21+-5.5

21+-5.5

17+-3.8

5+-0.6

-

5000

152+-18.0

23+-3.6

23+-3.6

24+-0.6

6+-2.3

+

0

154+-8.3

24+-8.4

24+-8.4

33+-4.4

16+-2.5

+

313

164+-2.9

27+-4.0

27+-4.0

35+-8.7

15+-1.0

+

625

173+-7.0

29+-5.2

29+-5.2

20+-1.0

13+-0.6

+

1250

141+-5.8

23+-7.4

23+-7.4

21+-3.0

11+-3.1

+

2500

135+-21.6

24+-8.3

24+-8.3

28+-2.9

13+-1.5

+

5000

143+-14.5

23+-4.6

23+-4.6

22+-5.9

10+-4.7

 

Chemical

AF-2

SA

AF-2

AF-2

9AA

 

Dose (µg/plate)

0.01

0.5

0.01

0.1

80

-

No colonies/plate

742+-20.0

702+-4.5

242+-18.9

648+-18.0

616+-41.5

 

Chemical

2AA

2AA

2AA

2AA

2AA

 

Dose (µg/plate)

1

2

10

0.5

2

+

No colonies/plate

1204+-51.4

413+-15.6

878+-88.1

518+-38.6

314+-34.8

Mutagenicity of dicumyl peroxide on bacteria (I)

 

 

 

 

No colonies/plate

 

 

+/- S9mix

DCP (µg/plate)

TA100

Ta1535

WP2 uvrA

TA98

TA1537

-

0

127+-20.0

14+-0.6

22+-1.2

23+-3.5

7+-3.2

-

313

129+-12.3

14+-2.6

22+-4.6

19+-2.6

5+-2.0

-

625

139+-9.0

10+-2.5

25+-8.6

21+-2.6

6+-0.0

-

1250

124+-5.5

11+-3.0

17+-4.6

21+-2.6

5+-5.0

-

2500

109+-7.8

11+-2.0

23+-1.5

18+-2.6

6+-0.6

-

5000

123+-23.0

9+-4.5

18+-1.5

19+-1.2

4+-0.6

+

0

127+-20.1

11+-2.1

31+-1.2

18+-1.7

15+-5.2

+

313

161+-15.6

13+-1.2

28+-3.8

26+-5.5

8+-2.0

+

625

137+-19.6

12+-3.6

35+-3.5

26+-6.4

16+-4.9

+

1250

139+-13.2

9+-0.6

28+-3.1

22+-2.6

10+-4.6

+

2500

131+-8.7

8+-5.1

33+-1.0

27+-1.5

13+-4.6

+

5000

125+-9.5

9+-5.7

27+-5.7

21+-4.4

6+-2.1

 

Chemical

AF-2

SA

AF-2

AF-2

9AA

 

Dose (µg/plate)

0.01

0.5

0.01

0.1

80

-

No colonies/plate

649+-28.5

714+-56.2

216+-8.7

640+-20.0

611+-99.0

 

Chemical

2AA

2AA

2AA

2AA

2AA

 

Dose (µg/plate)

1

2

10

0.5

2

+

No colonies/plate

970+-54.2

347+-12.6

1020+-72.7

440+-63.5

237+-30.1

 

At all concentrations of dicumyl peroxide was precipitate observed on the surface oft he agar plates.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

Dicumyl peroxide did not induced gene mutation in bacteria when tested up to 5000µg/plate, both with and without metabolic activation.
Executive summary:

A reverse mutation test of bis(1-methyl-1-phenylethyl) peroxide in bacteria was carried out. This substance was not mutagenic in Salmonella typhimurium TA100, TA1535, TA98, TA1537 and Escherichia coli WP2 uvrA, with or without an exogenous metabolic activation system.