Tripotassium propylsilanetriolate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

Pretest: 05.08.1996 to 08.08.1996. Main test: 07.10.1996 to 06.11.1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes

Type of study:

Buehler test

Justification for non-LLNA method:

An LLNA study was not performed because there is an existing reliable study for skin sensitisation using the Buehler test method. Furthermore, the LLNA test method is not considered to be suitable for substances that contain silicon. Please refer to the attached document for further details.

Test material

Test material information

Constituent 1

Reference substance name:

Trimethoxypropylsilane

EC Number:

213-926-7

EC Name:

Trimethoxypropylsilane

Cas Number:

1067-25-0

IUPAC Name:

trimethoxy(propyl)silane

Details on test material:

- Name of test material (as cited in study report): DYNASYLAN PTMO
- Substance type: Alkoxysilane
- Physical state: Colourless liquid
- Stability under test conditions: at least one year
- Storage condition of test material: inert atmosphere

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan Winkelmann GmbH, Borchen, GERMANY
- Age at study initiation: young adults
- Weight at study initiation: <500 g
- Housing: Makrolon Type IV, max 5/cage
- Diet : Ad libitum
- Water : Ad libitum
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/-3
- Humidity (%): 30-70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 : 12

IN-LIFE DATES: Pretest: 05.08.1996 to 08.08.1996. Main test: 07.10.1996 to 06.11.1996

Study design: in vivo (non-LLNA)

Induction

Route:

epicutaneous, occlusive

Vehicle:

corn oil

Concentration / amount:

Induction applications: neat
Challenge: 25%

Challenge

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

corn oil

Concentration / amount:

Induction applications: neat
Challenge: 25%

No. of animals per dose:

20 (test group); 10 (control)

Details on study design:

RANGE FINDING TESTS: conducted with groups of 3 animals.
Applications (6h occluded contact) of 5, 25, 50 and 100% TS with examination at 24 and 48 h following patch removal. 100% was identified as a suitable induction concentration (causing mild irritation), while 25% was identified as the lowest non-irritant challenge concentration.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3 dermal occlusive
- Exposure period: 6h
- Test groups: 20
- Control group: 10
- Frequency of applications: application on days 0, 7, 14
- Concentrations: TS neat or vehicle (corn oil) applied to the test and control groups, respectively (0.3 cc applied to a 2x2 cm patch)

B. CHALLENGE EXPOSURE
- No. of exposures: 1 (at two sites: TS and vehicle)
- Day(s) of challenge: day 28
- Exposure period: 6h
- Test groups: 20
- Control group: 10
- Site: flank
- Concentrations: 25% TS in corn oil and neat corn oil applied to both the test and control groups.
- Evaluation (hr after challenge): 24 and 48 h following patch removal

Challenge controls:

25% TS in corn oil and neat corn oil applied to both the test and control groups.

Positive control substance(s):

yes

Remarks:

2-mercaptobenzothiazol

Study design: in vivo (LLNA)

Statistics:

Not required.

Results and discussion

Positive control results:

Response rate of 30% (3/10 animals) indicates that the standard allergen is a sensitizer in the guinea pig under the conditions of this study. (See table 1.)

In vivo (non-LLNA)

Results

Results 1

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25% TS

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

None

Remarks on result:

no indication of skin sensitisation

Results 2

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

25% TS

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

None

Remarks on result:

no indication of skin sensitisation

Any other information on results incl. tables

Table 1: Incidence of dermal response to challenge dosing

GROUP	MATERIAL	INTERVAL (AFTER 6h CHALLENGE)	SKIN REACTIONS (NUMBER OF ANIMALS)	NUMBER OF ANIMALS	SENSITIZATION INCIDENCE INDEX**
Test	TS (25%)	24h	0	20	0/20=0%
		48h	0	20
	Vehicle	24h	0	20	0/20=0%
		48h	0	20
Positive control (2-mercaptobenzothiazol)	50% MCBT in vehicle	24h	3	10	3/10=30%*
		48h	0	10
	Vehicle (Vaseline)	24h	0	5	0/5=0%
		48h	0	5
Negative (vehicle) control	TS (25%)	24h	0	10	n/a
		48h	0	10
	Vehicle	24h	0	10	n/a
		48h	0	10

* The response of 30% in the positive controls confirms that the standard allergen tested is sensitizing in guinea pig under the conditions of this study.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In a guinea pig skin sensitisation study (Buehler test), conducted according to OECD 406 and to GLP (reliability score 1) trimethoxypropylsilane was not a skin sensitiser.