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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:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Research publication. Reasonably documented meets generally accepted scientific principles, acceptable for assessment

Data source

Reference
Reference Type:
publication
Title:
Genotoxicity of iron compounds in Salmonella typhimurium and L5178Y mouse lymphoma cells.
Author:
Dunkel VC, San RHC, Seifried HE, Whittaker P
Year:
1999
Bibliographic source:
DOI 10.1002/(SICI)1098-2280(1999)33:1<28::AID-EM4>3.0.CO;2-S PMID 10037321 Environ Mol Mutagenesis 33(1):28-41.

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
Principles of method if other than guideline:
Method: other: Ames (1975)
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Reference substance name:
10025-77-1
EC Number:
600-047-2
Cas Number:
10025-77-1
IUPAC Name:
10025-77-1
Constituent 2
Reference substance name:
Feric chloride FeCl3 x 6 H2O
IUPAC Name:
Feric chloride FeCl3 x 6 H2O
Test material form:
not specified
Details on test material:
Ferric chloride The substance tested was the hexahydrate (CAS number 10025-77-1, FeCl3.6H2O - 100% pure ex Mallinckrodt).

Stock solution of the compound was prepared immediately prior to use.
Final concentration of solvent was 10% water, 1% dimethyl sufoxide (DMSO) and 1N HCl

Method

Species / strain
Species / strain / cell type:
other: Salmonella typhimurium strains TA97a, TA98, TA100, TA102, TA1535, TA1537, TA1538
Metabolic activation:
with and without
Metabolic activation system:
Aroclor induced rat and hamster liver S9
Test concentrations with justification for top dose:
Plate incorporation assay (Ames et al, 1975) up to 10,000 µg Fe/plate + and - S9 (if no toxicity observed in preliminary dose range-finding study)
and Pre-incubation assay

10 dose levels were tested in the pre-incubation assay, and at least 5 doses in the plate incorporation assay (no details given)
Vehicle / solvent:
Vehicle used: 10% water, 1% dimethyl sufoxide (DMSO) and 1N HC
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
TA97 without S9 activation (75 µg/plate)
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
TA 98 without activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
TA 100 without activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
cumene hydroperoxide
Remarks:
TA 102 without activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene
Remarks:
TA 98 and 100 with activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: sterigmatocystin
Remarks:
TA 102 with activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene
Remarks:
TA97 with activation
Details on test system and experimental conditions:
METHOD OF APPLICATION:
For testing in absence of S9: 100ul tester strain, 50 µl solvent or test substance added tzo 2.5 ml molten selective top agar.
For testing in presence of S9: 0.5 ml S9 mix, 100 µl tester strain, 50 µl solvent or test substance added to 2 ml molten top agar.

in agar (plate incorporation); preincubation - in medium

DURATION
- Preincubation period: 20 min
- Exposure duration: 48 hours

SELECTION AGENT (mutation assays): minimal agar

NUMBER OF REPLICATIONS: doses were tested in triplicate in the plate incorporation assay .

DETERMINATION OF CYTOTOXICITY
- Method: cytotoxicity was determined by plating 10 doses with and without activation. Criteria to evaluate toxicity are not presented.


Evaluation criteria:
A substance is considered positive if it shows induction of at least doubling of mean number of revertants per plate in at least one tester strain, accompanied by a clear dose response. In strains TA 1537 and 1538, an increase in revertants of less than threefold will be confirmed in a repeat experiment.
Statistics:
Plates were counted in a MiniCount automated colony counter. The mean number of revertants of three plates was calculated.

Results and discussion

Test results
Species / strain:
S. typhimurium, other: TA98, TA100, TA102, TA1535, TA1537, TA1538
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
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

GENOTOXIC EFFECTS: 
Plate incorporation assay 
- With and without metabolic activation: No increase in reverse mutation rate in any strain at dose levels up to 10,000 ug/plate (revertant counts not 

reproduced in the publication)
- Preincubation assay: 

Results not presented for ferric chloride but lack of activity in this assay was demonstrated with ferrous sulphate and ferrous fumarate.


PRECIPITATION CONCENTRATION: None reported



Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative with metabolic activation
negative without metabolic activation

Ferric chloride Cas# 10025-77-1 FeCl3 x 6H2O is not a bacterial mutagen when tested using the bacterial reverse mutation assay in Salmonella typhimurium strains at dose levels up to 10000 µg Fe/plate.
Executive summary:

An Ames test with Salmonella typhimurium strains TA97a, TA98, TA100, TA102, TA1535, TA1537, TA1538 was conducted with FeCl3 x 6H2O dose levels up to 10000 µg Fe/plate. The cytotoxicity of the test substance was determined with and without metabolic activation (rat liver S9 mix) prior to the mutagenicity test in order to determine appropriate testing concentrations. All tests were perforrned in triplicates. As indication of a positive effect doubling of the mutant frequency was used.

A substance is considered positive if it shows induction of at least doubling of mean number of revertants per plate in at least one tester strain, accompanied by a clear dose response. In strains TA 1537 and 1538, an increase in revertants of less than threefold would be confirmed in a repeat experiment.

The Ames test showed neither with nor without metablic activation an increase in the number of revertants.

FeCl3 x 6H2O is negative for mutagenicity in presence and in the absence of metabolic activation under the conditions of this test system.