3-(methylthio)propionaldehyde

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1979-04 to 1979-05

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

no negative control group; instead positive control group (20 animals tested positive with 50.000 IU/100 g of Penicillin-G-Na); maximum non-irritating concentrations used for induction instead of highest to cause mild-to-moderate skin irritation; no details on animals and environmental conditions, no details on erythema and edema of individual animals

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

adopted 17 Jul 1992

Deviations:

yes

Remarks:

no negative control group but positive control group (50.000 IU/100 g of Penicillin-G-Na); maximum non-irritating concentrations used for induction instead of highest to cause mild-to-moderate skin irritation; topical induction for 24 h instead of 48 h

GLP compliance:

no

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The test was performed in 1979 before the alternative OECD guidelines (LLNA and in vitro test methods) were available.

Test material

Test material information

Constituent 1

Reference substance name:

3-(methylthio)propionaldehyde

EC Number:

221-882-5

EC Name:

3-(methylthio)propionaldehyde

Cas Number:

3268-49-3

Molecular formula:

C4H8OS

IUPAC Name:

3-(methylthio)propionaldehyde

In vivo test system

Test animals

Species:

guinea pig

Strain:

Pirbright-Hartley

Sex:

male

Details on test animals and environmental conditions:

- Source: Tierzüchterei Willy Krispien, Ahrensburg, Germany
- Animal body weight at study initiation: 300 - 320 g
- no data on housing, diet, water supply and environmental conditions

Study design: in vivo (non-LLNA)

Induction

Route:

intradermal and epicutaneous

Vehicle:

physiological saline

Concentration / amount:

intradermal induction on Day 1: 1%
epicutaneous induction on Day 7: 5%

Day(s)/duration:

intradermal induction: single treatment; epicutaneous induction: 24 h

Adequacy of induction:

other: Selection of concentration based on the results of the pre-test (determination of maximum non-irritating concentrations)

Challenge

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

5% in physiological saline

Day(s)/duration:

24 h

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

20

Details on study design:

RANGE FINDING TESTS:
The primary irritation by the test substance upon intracutaneous and epicutaneous exposure was tested in a pre-experiment. Graded dilutions of the test substance in physiological saline (2-fold dilution steps) were applied. The animals were induced with 0.1 mL test substance intradermally, followed by epicutaneous induction of 1 mL test substance one week later under occlusive conditions. Intracutaneous doses were tested in 5 animals each; each animal received up to 5 different concentrations. Epicutaneous doses were tested in 5 animals, each; but only one concentration per animal. Skin reactions were evaluated 24 h post application. Concentrations for the main experiment were chosen to be the highest non-irritating concentration.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2 (intradermal and epicutaneous, respectively)
- Exposure period: single injection (intradermal) and 48 h (epicutaneous)
- Test groups:
Intradermal (3 pairs of injections):
Injection 1: 1:1 (v/v) mixture complete Freund's adjuvant (FCA) and distilled water
Injection 2: 1% test substance in phosphate buffered saline (PBS)
Injection 3: 1% test substance in a 1:1 mixture of complete Freund's adjuvant (FCA) and PBS
Epicutaneous: One week after the injections, a 2 x 4 cm patch of gauze was soaked with 5% test item formulated in PBS and applied to the test site. The treated areas were covered with alufoil and fixed with an elastic bandage for 24 h.
- Control group: Not included in the study.

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day of challenge: 2 weeks after epidermal induction (Day 20)
- Exposure period: 24 h
- Test groups: test substance
- Concentrations: 5% formulation in PBS
- Evaluation (hr after challenge): 48 h

Challenge controls:

Not included in the study.

Positive control substance(s):

yes

Remarks:

Penicillin-G-Na

Results and discussion

Positive control results:

All animals induced intracutaneously, epicutaneously and challenged with 50.000 IU / 100 g of Penicillin-G-Na tested positive in this study.

In vivo (non-LLNA)

Results

Results 1

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

induction: 1% intradermal, 5% epicutaneous; challenge 5%

No. with + reactions:

20

Total no. in group:

20

Clinical observations:

no

Results 2

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

induction: 50.000 IU / 100 g intradermal, 50.000 IU / 100 g epicutaneous; challenge 550.000 IU / 100 g

No. with + reactions:

20

Total no. in group:

20

Clinical observations:

no

Results 3

Reading:

2nd reading

Group:

negative control

Remarks on result:

other: No negative control included in this study.

Any other information on results incl. tables

No mortality or adverse clinical observations were reported in this study. In addition, the result of the first reading time point after challenge were not reported.

Applicant's summary and conclusion

Interpretation of results:

Category 1A (indication of significant skin sensitising potential) based on GHS criteria

Conclusions:

CLP: Skin sens. 1, H317 according to Regulation (EC) No. 1272/2008

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