Slags, elec. furnace smelting, iron silicate

Skin sensitisation

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

Test material information

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)

Results

Results 1

Parameter:

SI

Remarks on result:

other: Not reported

Results 2

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.