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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1985
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study
Remarks:
The study methodology followed was equivalent or similar to EU Method B.6 and was conducted in accordance with the Principles of GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1985
Report Date:
1985

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
EU Method B.6 (Skin Sensitisation)
GLP compliance:
yes
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
Existing reliable GPMT study already available.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
1-methoxypropan-2-ol is a close structural analogue of 1-ethoxypropan-2-ol, which is the major hydrolysis product of the submission substance (2-ethoxy-1-methyl ether acetate). Details for the surrogate material:
- Analytical purity: Analysed purity 99% .
- Supplied by Merck, manufacturer’s quoted purity >99%
- Impurities: peroxides 0.5-2mg/l.

A detailed justification for read across within the P series glycol ethers is attached to chapter 13 of the IUCLID dossier for this substance.

In vivo test system

Test animals

Species:
guinea pig
Strain:
not specified
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Porcellus Ltd.
- Age at study initiation: not specified in the report
- Weight at study initiation: 505-612 g
- Housing: 2-3 animals/cage
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 2 weeks
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-23 °C
- Humidity (%): not specified in the report
- Air changes (per hr): not specified in the report
- Photoperiod (hrs dark / hrs light): 12 hour light/dark cycle

Study design: in vivo (non-LLNA)

Induction
Route:
intradermal and epicutaneous
Vehicle:
unchanged (no vehicle)
Concentration / amount:
0.1 ml of undiluted methyl proxitol
Adequacy of induction:
not specified
Challenge
Route:
epicutaneous, occlusive
Vehicle:
unchanged (no vehicle)
Concentration / amount:
0.1 ml of undiluted methyl proxitol
Adequacy of challenge:
not specified
No. of animals per dose:
Test group - 10 males + 10 females
Control group - 5 males + 5 females
Details on study design:
RANGE FINDING TESTS: The purpose of the range finding studies was to determine the concentrations
of methyl proxitol to be used for intradermal injections, topical induction and topical challenge.
MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: total of 4 intradermal injections (2 injections - 0.1 ml in corn oil and 2 injections - 0.1
ml in 50:50 FCA/corn oil), after one week of the intradermal injection, topical application for 48 hours
- Exposure period: same as above
- Test groups: one
- Control group: one
- Site: the animals were closely shorn in the shoulder region using electric clippers followed by an electric
razor, two rows of three injections were made, one on each side of the midline
- Frequency of applications: one topical application
- Duration: 48 hours
- Concentrations: 0.3 ml of methyl proxitol
B. CHALLENGE EXPOSURE
- No. of exposures: single
- Day(s) of challenge: two weeks after topical induction
- Exposure period: 24 hours
- Test groups: one
- Control group: one
- Site: on the flank
- Concentrations: 0.1 ml of undiluted methyl proxitol
- Evaluation (hr after challenge): immediately after patch removal, 24 and 48 hours after patch removal
Challenge controls:
not applicable
Positive control substance(s):
no

Results and discussion

Positive control results:
not applicable

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
undiluted
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
none
Remarks on result:
no indication of skin sensitisation
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
undiluted
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
none
Remarks on result:
no indication of skin sensitisation

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
Based on the results of the study, methyl proxitol is not a skin sensitizer.
Executive summary:

Skin sensitization study of methyl proxitol was conducted in groups of guinea-pigs (test group - 10 males + 10 females, negative control group - 5 male + 5 female) at the following concentrations - intradermal induction (0.1% m/v in corn oil), topical induction (undiluted) and topical challenge (undiluted). None of the 20 test animals showed any positive response at either 24 and 48 hours after removal of the challenge patches. Based on the results of the study, methyl proxitol was not concluded as a skin sensitizer in guinea-pigs.