Tetrapropyl orthosilicate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Study period:

02.11.1992 to 10.12.1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to an appropriate OECD test guideline, with acceptable restrictions. The restriction was a reduced number of test animals.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

yes

Remarks:

Only ten test animals; guideline requires 20, and details of the laboratory control not presented in the report.

GLP compliance:

yes

Type of study:

Buehler test

Test material

Test material information

Constituent 1

Reference substance name:

Tetraethyl orthosilicate

EC Number:

201-083-8

EC Name:

Tetraethyl orthosilicate

Cas Number:

78-10-4

IUPAC Name:

tetraethyl orthosilicate

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Winkelmann Co., 4799 Borchen
- Age at study initiation: 'Young'
- Weight at study initiation: 424±23 g
- Housing: Conventional, maximum of 5 per Macrolon cage Type IV.
- Diet (e.g. ad libitum): Ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: At least five days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20±3
- Humidity (%): 30-70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: 03.11.1992 to 10.12.1992

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

epicutaneous, occlusive

Vehicle:

other: T52-003:MEH 56 corn oil

Induction 2

Concentration / amount:

100% for first two inductions and 50% for third induction and challenge.

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

other: T52-003:MEH 56 corn oil

Challenge 2

Concentration / amount:

100% for first two inductions and 50% for third induction and challenge.

No. of animals per dose:

10

Details on study design:

RANGE FINDING TESTS: Gauze sponges measuring 2cm x 2cm were each coated with about 0.4 g of test substance in MEH 56 corn oil at concentrations of 2.5, 25, 50 or 100% and applied to the shaved flank area. Each gauze was covered with an occlusive dressing and held in place for 6 hours by bandage. After removal of the patch, the remaining substance was removed using corn oil and a cellulose swab. The dermal reaction was evaluated immediately after patch removal and again at 24 and 48 hours.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: Three
- Exposure period: Six hours
- Test groups: 100 % test substance for inductions 1 and 2, and 50% for induction 3.
- Control group: MEH 56 corn oil
- Site: Left flank
- Frequency of applications: Every seven days


B. CHALLENGE EXPOSURE
- No. of exposures: One
- Day(s) of challenge:Day 28
- Exposure period: Six hours
- Test groups: ethyl silicate
- Control group: MEH 56 corn oil
- Site: Right flank
- Concentrations: 50%
- Evaluation (hr after challenge): 6, 24, 48 and 72 after bandage removal.

Challenge controls:

Negative control was MEH 56 corn oil.

Positive control substance(s):

no

Study design: in vivo (LLNA)

Statistics:

No details given.

Results and discussion

Positive control results:

No positive control.

In vivo (non-LLNA)

Results

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

50%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

None

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 50%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: None.

Any other information on results incl. tables

There were no substance related effects or influence on body weight in either test or control animals. Very light
erythema and edema were observed in 2 of 10 animals during Induction Phase I, and in 3 of 10 animals in Induction Phase
II; no skin irritation was observed in the control animals. There was no skin irritation observed in either test or control animals in Induction Phase III or in the Challenge Phase (24, 48 and 72 h).

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

In a skin sensitisation study (Buehler test; reliability score 2) conducted to OECD 406 (except only 10 test animals and no positive control) DYNASIL A (tetraethoxysilan) was not sensitising to the skin of guinea-pigs.

Executive summary:

In a skin sensitisation study (Buehler test; reliability score 2) conducted to OECD 406 (except only 10 test animals and no positive control) DYNASIL A (tetraethoxysilane) was not sensitising to the skin of guinea-pigs.