Barium carbonate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline conform study with GLP

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

barium(2+) dichloride dihydrate

EC Number:

600-412-6

Cas Number:

10326-27-9

Molecular formula:

BaCl2.2(H2O)

IUPAC Name:

barium(2+) dichloride dihydrate

Details on test material:

- Name of test material (as cited in study report): barium chloride dihydrate
- EC number: 233-788-1
- Substance type: pure active substance
- Physical state: a whcitrey stalline granule or powder

Method

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 97

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

100, 333, 1000, 3333, 10000 µg/plate, duplicate cultures

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: water
- Justification for choice of solvent/vehicle: no data

Controls

Controls 1

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-Aminoanthracen (all strains in the presence of S9)

Controls 2

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

TA1535 and TA100

Controls 3

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

TA97 and TA1537

Controls 4

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 4-nitro-o-phenylenediamine (TA98)

Details on test system and experimental conditions:

METHOD OF APPLICATION: pre-incubation; barium chloride dihydrate was incubated with the Salmonella typhimurium tester strains
either in buffer or S9 mix for 20 minutes at 37°C. Top agar supplemented with I-histidine and d-biotin was added, and the contents of the tubes were mixed and poured onto the surfaces of minimal glucose agar plates.

DURATION
- Exposure duration: 20 minutes
- Expression time (cells in growth medium): 2 days at 37°C

NUMBER OF REPLICATIONS: Each trial consisted of triplicate plates of concurrent positive and negative controls, and of at least five doses of barium chloride dihydrate.


No further details are given.

Evaluation criteria:

In this test, a positive response was defined as a reproducible, dose-related increase in histidin-independent (revertant) colonies in any one strain/activation combination. An equivocal response was defined as an increase in revertants that was not dose related, not reproducible, nor was of sufficient magnitude to support a determination of mutagenicity. A negative response was obtained when no increase in revertant colonies was observed following chemical treatment. There was no minimum percentage or fold increase required for a chemical to be judged positive or weakly positive.

Statistics:

Statistical analysis is not mandatory for the bacterial reverse mutation assay.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 97

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: slight toxicity at concentration from 333 to 10000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: slight toxicity at concentration from 333 to 10000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: slight toxicity at concentration from 333 to 10000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: slight toxicity at concentration from 333 to 10000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 5

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: slight toxicity at 10000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

no data

Applicant's summary and conclusion

Conclusions:

No increased induction of revertant colonies at all concentrations in all strains with and without metabolic activation.

Executive summary:

Read across from BaCl2*2H2O to BaCO3:

Based on the negative results in thein-vitrotest for the soluble barium compound (BaCl2*2H2O) and assuming that poorly soluble compounds are less bioavailable, read-across from BaCl2*H2O is performed.