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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Sep. 10, 1987 - Nov. 16, 1988
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report Date:
1988

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Principles of method if other than guideline:
Ames test in salmonella & E. coli, with and without S9-activation
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: nanoform, surface-treated
Specific details on test material used for the study:
surface treated synthetic amorphous silicon dioxide HDK VP KHD 50

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
Species / strain / cell type:
E. coli WP2 uvr A pKM 101
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254 induced rat liver post-mitochondrial fraction (S-9)
Test concentrations with justification for top dose:
8, 40, 200, 500, 1000, 1500, 3000, 5000 µg/plate
Vehicle / solvent:
DMSO
Controls
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
4-nitroquinoline-N-oxide
9-aminoacridine
2-nitrofluorene
sodium azide
other: 2-aminoanthracene

Results and discussion

Test resultsopen allclose all
Key result
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not determined
Vehicle controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not determined
Vehicle controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not determined
Vehicle controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not determined
Vehicle controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
ambiguous
Remarks:
s. remark below
Cytotoxicity / choice of top concentrations:
not determined
Vehicle controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
E. coli WP2 uvr A pKM 101
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not determined
Vehicle controls validity:
valid
Positive controls validity:
valid
Additional information on results:
When tested as a suspension up to a dose of 5000 µg/plate, HDK VP KHD 50 failed to induce mutation in four histidine-requiring strains of Salmonella typhimurium and two tryptophan-requiring strains Escheria coli either in the absence or presence of rat liver S-9. It was concluded that HDK VP KHD 50 has no mutygenic activity in this assay.

Any other information on results incl. tables

As two fold increases in numbers of E. coli WP2 uvrA- revertants occured both in the absence and presence of S-9, a second experiment was conducted with no similar increase. Therefore the authers accorded no biological significance to it.

Applicant's summary and conclusion

Conclusions:
surface treated synthetic amorphous silicon dioxide HDK VP KHD 50 was not mutagenic under the test conditions
Executive summary:

An Ames test was conducted with surface treated synthetic amorphous silicon dioxide HDK VP KHD 50H.