Disodium metasilicate

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

yes

Remarks:

1-fluoro-2,4-dinitrobenzene (DNFB) as positive  control

GLP compliance:

not specified

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

Balb/c

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS: 
- Source: National Cancer Institute, USA
- Age: 45 - 60 days
- Weight at study initiation: 17 - 20 g

Vehicle:

other: 15% ethanol

Concentration:

2, 4 and 6%

Details on study design:

RANGE FINDING TESTS:
- Irritation: A primary irritancy assay was performed to establish the  minimal irritating and the maximal non-irritating concentration.

TREATMENT PREPARATION AND ADMINISTRATION:
Test solutions were  prepared daily in amber vials using 15% ethanol.

Positive control substance(s):

other: 1-fluoro-2,4-dinitrobenzene (DNFB)

Statistics:

Bartlett's chi-square Test, one-way ANOVA and  Dunnett's Multiple Range t Test

Parameter:

SI

Remarks on result:

other: no data

RESULTS OF PILOT STUDY: minimal irritating concentration: 6%; maximal  non-irritating concentration: 4%

 
RESULTS OF TEST
- Sensitization reaction: sensitization with 2-6% did not significantly  alter cell proliferation in the auricular lymph nodes,

even though an  increase of 30% and 40% at the 4% and 6% treatment levels was measured,  respectively. A greater than

30-fold increase was measured in the  positive control.

Interpretation of results:

not sensitising

Remarks:

Migrated information

Reference 2

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Method not validated; unsuitable test system. The MEST failed to prove as a valid test in the validation process (ECETOC Technical Report No. 78, 1999).

Principles of method if other than guideline:

Method: other: MEST

GLP compliance:

not specified

Type of study:

mouse ear swelling test

Species:

mouse

Vehicle:

other: 15% ethanol

Vehicle:

other: 15% ethanol

Details on study design:

1st application: Induction 4 % open epicutaneous
2nd application: Challenge 6 % open epicutaneous

RS-Freetext:
RESULTS OF PILOT STUDY: minimal irritating concentration: 6%; maximal  non-irritating concentration: 4%
RESULTS OF TEST
- Sensitization reaction: 15% increase in ear swelling 48 h after  challenge for mice that were sensitized with 4% metasilicate. 28%  increase with positive control. According to the authors sodium  metasilicate is a weak sensitizer in this test system.
- Clinical signs: not reported
- Rechallenge: not performed

Interpretation of results:

sensitising

Remarks:

Migrated information

Endpoint conclusion

Additional information:

Disodium metasilicate was not sensitizing in the local lymph node assay. In a human case report, contact urticaria induced by sodium silicate was observed in one individual.

Migrated from Short description of key information:
Disodium metasilicate is not sensitising (LLNA).

Respiratory sensitisation

Endpoint conclusion

Additional information:

Not required. No data available.

.

Justification for classification or non-classification

The available data is conclusive but not sufficient for classification.