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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in mammalian cells
Type of information:
experimental study
Adequacy of study:
key study
Study period:
No data
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
other: 40 CFR Part 158 US-EPA-FIFRA, Section 156.340
Deviations:
no
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)
Deviations:
not specified
GLP compliance:
yes
Type of assay:
mammalian cell gene mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
Boric acid
EC Number:
233-139-2
EC Name:
Boric acid
Cas Number:
10043-35-3
Molecular formula:
H3BO3
IUPAC Name:
Boric acid
Details on test material:
- Name of test material: Boric acid, Granular Technical Grade; Granular Technical Grade Supplied by US Borax Inc.
- Analytical purity: > 99 %
- Stability: Stable

Method

Target gene:
Thymidine kinase, TK locus of the L5178Y mouse lymphoma cell line
Species / strain
Species / strain / cell type:
mouse lymphoma L5178Y cells
Details on mammalian cell type (if applicable):
No data
Additional strain / cell type characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
S9 mix or other (Aroclor 1254 induced rat (Fischer 344) liver S9 fraction used at 1 %).
Test concentrations with justification for top dose:
0, 1.2, 1.7, 2.45, 3.5 and 5.0 mg/mL boric acid.
Vehicle / solvent:
No data
Controlsopen allclose all
Positive controls:
yes
Positive control substance:
3-methylcholanthrene
Positive controls:
yes
Positive control substance:
other: Hycanthone methylsulphonate
Details on test system and experimental conditions:
METHOD OF APPLICATION: ROP plus 5 % heat treated horse serum

NUMBER OF CELLS EVALUATED: Approximately 600/dose
Evaluation criteria:
Mutations at the TK locus
Statistics:
No data

Results and discussion

Test results
Species / strain:
mouse lymphoma L5178Y cells
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
Concentration related cytoxicity (60 % reduction over controls at 5 mg/mL)
Additional information on results:
Concentration related cytotoxicity (60 % reduction over controls at 5 mg/mL).
Increase in ouabain resistance seen (not significant).
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Gene mutation assay results:

Concentration

mg/mL

Number of mutant cells per 106cells ± SD

Comments give information

on cytotoxicity or other

Exp 1

Exp 2

Exp 1

Exp 2

-S9

-S9

+S9

+S9

0

54 ± 10

42 ± 1

29 ± 10

36 ± 7

 

1.2

46 ± 28

38 ± 15

34 ± 0

36 ± 7

 

1.7

39 ± 17

31 ± 9

41 ± 7

49 ± 4

 

2.45

27 ± 3

32 ± 9

40 ± 16

36 ± 6

Minor cytotoxicity seen

3.5

31 ± 18

46 ± 1

41 ± 13

41 ± 6

Cytotoxicity seen

5

50 ± 22

41 ± 5

53 ± 2

47 ± 3

Cytotoxicity seen. Increase in + S9 in first study not reproduced.

Applicant's summary and conclusion

Conclusions:
The test substance was not mutagenic but cytotoxicity observed at 5 mg/mL (maximum dose level).