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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:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study.

Data source

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

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
yes (incl. certificate)
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
S9 from livers of aroclor 1254 induced rats
Test concentrations with justification for top dose:
0.001, 0.004, 0.02, 0.10, 0.30, 1.00 mg/plate
Vehicle / solvent:
acetone
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 4-nitroquinoline-N-oxide, 2-acetylaminofluorene, benzo(a)pyrene, NaNO2, 2-aminoanthracene, 9-aminoacridine
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)
0.1 ml of bacterial culture, test solution, and, for tests with metabolic activation, 0.5 ml S-9 mix, were mixed with 2 ml top agar, then poured into minimal glucose agar plates.

DURATION
- Exposure duration: 48 hrs, incubated at 37°C

NUMBER OF REPLICATIONS: 3


OTHER: For plates with more than 500 revertant,colonies/plates, number of revertant colonies were counted using a stereomicroscope. An Artek model 880 automatic colony counter was used for other plates. Visual examination was used for plates with <10 revertants/plate.
Evaluation criteria:
A positive response was considered to be three treatment levels with revertants/plate greater than solvent control and a significant positive dose response (p<0.01).
Statistics:
Analyses included Bartlett's test, one-sided t-test, Grubb's test, and regression analysis.

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:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Water solubility: test substance was not soluble at concentrations above 1 mg/plate

ADDITIONAL INFORMATION ON CYTOTOXICITY: Cytotoxicity tests show the test substance was not cytotoxic at concentrations up to 10 mg/plate. This was higher than the solubility of the test substance.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Results for TA1538 and TA1537 – Experiment I (Revertants/plate (SD))

Concentration (mg/plate)

TA1535 – Without S9

TA1535 – With S9

TA1537 – Without S9

TA1537 – Without S9

0.001

17.3  (6.8)

7.0 (3.6)

7.0 (4.0)

4.3 (2.1)

0.004

15.0 (2.6)

9.3 (3.1)

6.3 (3.2)

7.0 (3.0)

0.02

18.0 (3.0)

9.0 (2.6)

6.3 (0.6)

7.0 (1.7)

0.10

13.7 (4.0)

8.3 (0.6)

6.0 (2.0)

6.7 (3.1)

0.30

18.0 (5.3)

10.3 (4.0)

3.7 (2.9)

5.7 (1.5)

1.00

18.7 (6.1)

11.0 (5.2)

3.0 (2.0)

3.3 (1.2)

Solvent Control

12.4 (4.9)

9.4 (1.9)

7.7 (2.5)

7.6 (3.6)

Non-solvent Control

9

3

7

4

Positive Control 0.001-0.5

100

51

8

29

Positive Control 0.005-2.5

286

271

5

138

Positive Control 0.01-5

347

304

46

Toxicity Observed

Results for TA1538 and TA1537 – Experiment II (Revertants/plate (SD))

Concentration (mg/plate)

TA1535 – Without S9

TA1535 – With S9

TA1537 – Without S9

TA1537 – Without S9

0.001

18.3  (4.2)

10.3 (1.2)

8.0 (1.0)

9.7 (4.7)

0.004

19.7 (3.5)

13.3 (1.5)

6.0 (2.6)

9.7 (5.5)

0.02

14.3 (3.2)

13.0 (3.5)

7.0 (1.7)

13.3 (0.6)

0.10

15.3 (9.2)

10.7 (1.5)

10.3 (3.1)

11.0 (2.6)

0.30

18.7 (1.5)

9.0 (1.7)

6.7 (1.5)

12.0 (4.6)

1.00

19.7 (5.5)

10.7 (2.3)

10.0 (4.4)

13.0 (2.6)

Solvent Control

16.6 (2.1)

10.8 (2.7)

8.6 (2.9)

11.6 (3.0)

Non-solvent Control

17

12

9

8

Positive Control 0.001-0.5

101

77

12

43

Positive Control 0.005-2.5

421

262

21

237

Positive Control 0.01-5

2100

399

180

Toxicity Observed

Results for TA98 and TA100 – Experiment I (Revertants/plate (SD))

Concentration (mg/plate)

TA98 – Without S9

TA98 – With S9

TA100 – Without S9

TA100 – Without S9

0.001

13.7  (4.6)

40.7 (6.4)

85.7 (5.9)

92.3 (1.5)

0.004

13.3 (1.5)

30.3 (10.0)

84.3 (15.0)

95.0 (15.9)

0.02

13.7 (1.5)

38.0 (4.6)

84.3 (5.1)

87.0 (11.1)

0.10

13.3 (4.0)

31.0 (7.0)

92.5 (3.5)

86.3 (14.5)

0.30

11.7 (1.2)

29.7 (6.4)

97.7 (8.4)

96.0 (4.6)

1.00

15.7 (5.3)

40.0 (10.4)

93.3 (2.9)

104.0 (21.7)

Solvent Control

12.4 (4.9)

39.6 (8.4)

84.2 (8.3)

91.4 (9.2)

Non-solvent Control

20

39

100

106

Positive Control 0.002-0.01

33

287

118

204

Positive Control 0.001-0.05

30

1800

145

805

Positive Control 0.02-0.1

69

3800

204

1200

Results for TA98 and TA100 – Experiment II (Revertants/plate (SD))

Concentration (mg/plate)

TA98 – Without S9

TA98 – With S9

TA100 – Without S9

TA100 – Without S9

0.001

15.0  (2.0)

35.0 (3.0)

82.7 (2.1)

89.0 (11.5)

0.004

20.0 (4.4)

40.0 (6.1)

83.0 (3.6)

84.7 (2.1)

0.02

18.0 (6.6)

37.0 (2.0)

92.7 (16.8)

88.3 (8.1)

0.10

23.3 (3.2)

33.3 (8.0)

84.0 (21.5)

93.7 (12.2)

0.30

19.0 (1.0)

30.3 (1.2)

89.0 (7.8)

97.7 (15.2)

1.00

19.0 (2.6)

36.3 (7.1)

98.7 (15.6)

101.3 (5.7)

Solvent Control

19.2 (4.1)

35.0 (5.3)

83.2 (9.3)

78.9 (10.6)

Non-solvent Control

20

31

95

108

Positive Control 0.002-0.01

26

413

86

230

Positive Control 0.001-0.05

45

900

157

1200

Positive Control 0.02-0.1

73

1500

152

1900

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

The test substance is not cytotoxic or mutagenic either in the presence or absence of metabolic activation.
Executive summary:

This study examined the potential mutagenicity of the test substance Therminol 55 Heat-Transfer Medium. Concentrations of 0.001, 0.004, 0.02, 0.10, 0.30, 1.00 mg/plate of test substance were added to bacterial cultures of Salmonella strains TA 1535, TA 1537, TA 100, and TA 98. 4-nitroquinoline-N-oxide, 2-acetylaminofluorene, benzo(a)pyrene, NaNO2, 2-aminoanthracene, and 9 -aminoacridine were used as positive control substances. Acetone was used as a solvent. The test substance was also tested for cytotoxicity at concentrations up to 10 mg/plate, higher than the solubility limit of 1 mg/plate. Results show the test substance was not cytotoxic even at 10 mg/plate. Results also show no statistically significant increase in the number of revertants/plate in any of the strains at any concentration. The test substance is not mutagenic either in the presence or absence of metabolic activation.