Triethoxypropylsilane

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

13.02.1992 to 24.04.1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

occluded dressing

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Triethoxypropylsilane

EC Number:

219-842-7

EC Name:

Triethoxypropylsilane

Cas Number:

2550-02-9

Molecular formula:

C9H22O3Si

IUPAC Name:

triethoxy(propyl)silane

Test animals

Species:

rabbit

Strain:

other: White Russian

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: ASTA Medica AG, Halle-Kűnsebeck, GERMANY
- Age at study initiation: 5-7 months
- Weight at study initiation: Males: 2.10, 2.27 kg; Females: 2.31 kg
- Housing: 1/ stainless steel cage
- Diet: standard diet ad libitum
- Water: drinking water ad libitum
- Acclimation period: 1 day

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-22.5
- Humidity (%): 50-60
- Air changes (per hr): not given
- Photoperiod (hrs dark / hrs light): 12 /12

IN-LIFE DATES: From: 1992-02-25 (stated) To: 1992-02- 11 (estimated)

Test system

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 mL
- Concentration: neat

Duration of treatment / exposure:

4 h

Observation period:

Observed at 1, 24, 48 and 72 h, and daily until day 14. Data are reported only for days 4, 7, 10 and 14.

Number of animals:

3 (2 male, 1 female)

Details on study design:

TEST SITE
- Area of exposure: 6.25 cm²
- % coverage: not stated
- Type of wrap if used: 3-ply patch: cellulose gauze, artificial wool coated with natural rubber, "synthetic film glue"; wrap: "acrylastic" bandage

REMOVAL OF TEST SUBSTANCE
- Washing: washed off gently
- Time after start of exposure: 4 h

SCORING SYSTEM: as given in OECD 404. Grading according to Gilman et al. 1983.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

other: mean out of animals #1 and #2

Time point:

24/48/72 h

Score:

3

Max. score:

4

Reversibility:

fully reversible within: 14 days

Remarks on result:

other: in animal #1 a brownish discolouration of the treated site was observed up to 5 days post-application

Results 2

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 14 days

Results 3

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

2.3

Max. score:

4

Reversibility:

fully reversible within: 7 days

Results 4

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1.7

Max. score:

4

Reversibility:

fully reversible within: 10 days

Results 5

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 10 days

Irritant / corrosive response data:

All three animals formed skin scales 6-7 days after treatment. The scales peeled off 1-2 days afterwards. See table 1 for detail.

Other effects:

None. The general condition of the test animals was not affected.

Any other information on results incl. tables

Table 1: Irritant/corrosive response data for each animal at each observation time up to removal of each animal from the test

Score at time point / Reversibility	Erythema & eschar	Edema
	Max. score: 4	Max. score: 4
1 h	2/2/2	4/3/3
24 h	3/3/2	3/2/1
48 h	3/3/2	2/2/1
72 h	3/3/2	2/1/1
Day 4	3/3/2	2/1/1
Day 7	1/1/1	0/1/1
Day 10	1/0/1	0/0/0
Day 14	0/-/0	0/-/0
Mean 24, 48, 72 h	3/3/2	2.3/1.7/1
Mean 1, 24, 48, 72 h; 3 animals	2.5	2.08
Reversibility*	c	c
Average time for reversion	Day 14	Day 10

* Reversibility: c. = completely reversible; n.c. = not completely reversible; n. = not reversible

PII= 4.6; graded moderately irritant (Gilman et al.1983)

erythema/eschar >=2.3 in 2 of 3 animals; category 2 irritant according to EC criteria

 

Applicant's summary and conclusion

Interpretation of results:

other: Category 2 based on CLP criteria (EU criteria according to Regulation (EC) No. 1272/2008)

Conclusions:

In a skin irritation study conducted largely in accordance with OECD 404 and to GLP (reliability score 1) but using an occlusive dressing, found triethoxypropylsilane to be moderately irritating to the skin of rabbits. Current EC criteria would concur with the findings of this study (as conducted), although it is possible that the use of a semi-occlusive dressing might reduce the irritation observed.