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Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well documented study report which meets basic scientific principles. Read-across to other silicates.

Data source

Reference
Reference Type:
publication
Title:
Sodium metasilicate hypersensitivity in BALB/c mice.
Author:
Karrow N.A, Guo T.L, Leffel E.K, Zhang L.X, McCay J.A, Germolec D.R, K.L.Jr White
Year:
2002
Bibliographic source:
Am J Contact Derm 13, 133-139

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
yes
Remarks:
DNFB used as positive control. Test substance applied to both sides of each ear.
GLP compliance:
not specified
Type of study:
mouse local lymph node assay (LLNA)

Test material

Constituent 1
Reference substance name:
Sodium metasilicate
IUPAC Name:
Sodium metasilicate
Details on test material:
Sodium metasilicate obtained from Aldrich Chemical Company (Milwaukee, USA).
No other data presented.

In vivo test system

Test animals

Species:
mouse
Strain:
Balb/c
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: National Cancer Institute
- Age at study initiation: 45-60 days
- Weight at study initiation: 17-20 g
- Housing: 4 animals per cage in plastic shoe box cages
- Diet (e.g. ad libitum): Agway-certified diet NIH-07 ad libitum
- Water (e.g. ad libitum): tap water ad libitum
- Acclimation period:ca 1 week


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-26 C
- Humidity (%): 40-70%
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12 h


IN-LIFE DATES: From: To:

Study design: in vivo (LLNA)

Vehicle:
other: ethanol
Concentration:
15%
No. of animals per dose:
4
Details on study design:
Mice were treated for 3 days with sodium metasilicate: 1st induction 2%, 2nd induction 4%, 3rd induction 6%
Positive control substance(s):
other: 1-fluoro-2,4-dinitrobenzene (DNFB)
Statistics:
Bartlett's X2 test followed by one-way analysis of variance (ANOVA) followed by Dunnett's multiple range t-test, or by nonparametric analysis of variance and the Wilcoxon's Rank Sum test. Student's t-test was used to compare the positive control group to the positive vehicles.

Results and discussion

Positive control results:
>30% increase

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: Not reported
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: Not reported

Any other information on results incl. tables

No significantly altered cell proliferation in the auricular lymph nodes. An unsignificant increase of 40% and 30% at the 4% and 6% soldium metasilicate concentrations were measured, respectively. The positive control induced >30 -fold increase in cell proliferation in the auricular lymph nodes.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
Sensitisation of mice with 2%, 4% and 6% sodium metasilicate for 3 consecutive days did not exhibit a significant effect on cell proliferation in the auricular lymph nodes.
Executive summary:

The sensitisation potential of sodium metasilicate in mice was tested by the local lymph node assay (Karrow et al. 2002). Sensitisation with 2%, 4% and 6% sodium metasilicate for three consecutive days did not exhibit a significant effect on cell proliferation in the auricular lymph nodes.