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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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1979
Report Date:
1979
Reference Type:
study report
Title:
Unnamed
Year:
1979
Report Date:
1979

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
yes
Remarks:
Induction phase comprised 1st and 2nd induction, each subdivided into intradermal and epidermal treatment with 1-week-intervals between each treatment.
Principles of method if other than guideline:
Study was performed as modification of the Magnusson-Kligman test before the actual guideline was adopted.
GLP compliance:
no
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
The Guinea Pig Maximazitation Test (1979) met the previous requirements before the entry into force of REACH. The GPMT is suitable and reliable to cover this endpoint. For this reason and for animal welfare reasons, no further in vivo study (LLNA test) needs to be performed.

Test material

Reference
Name:
Unnamed
Type:
Constituent

In vivo test system

Test animals

Species:
guinea pig
Strain:
other: Pirbright White
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Firma Hagemann, Lippische Versuchstierzucht, 4923 Extertal
- Weight at study initiation: 449 - 824 g
- Diet (e.g. ad libitum): Ssniff K, ad libitum
- Water (e.g. ad libitum): ad libitum

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
water
Concentration / amount:
50%
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
water
Concentration / amount:
50%
No. of animals per dose:
1st study: 10 test, 5 control
2nd study: 12 test, 5 control
Details on study design:
MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 4
- Exposure period: d 0 (1st intradermal), 7 (1st epicutaneous), 14 (2nd intradermal), 21 ( 2nd epicutaneous)
- Test groups: 1st intradermal: 6 parallel injections with Freund's adjuvant, 50% methanol and Freund's adjuvant + 50% methanol, respectively; 2nd intradermal: 4 parallel injections with 50% methanol and Freund's adjuvant + 50% methanol, respectively; both epidermal: conc. methanol
- Control group: no induction treatment
- Site: shoulder region
- Frequency of applications: weekly
- Duration: epicutaneous: 48 h occlusive
- Concentrations: 50% intradermal, 100% epicutaneous


B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 34 days after 1st intradermal induction
- Exposure period: 24 h occlusive
- Test groups: 1st study: right 50% methanol, left 25% formaldehyde epicutaneous; 2nd study: concentrated methanol epicutaneous
- Control group: 1st study: right 50% methanol, left 25% formaldehyde epicutaneous; 2nd study: concentrated methanol epicutaneous
- Site: flank
- Concentrations: 50% methanol and 25% formaldehyde, respectively (study 1), 100% methanol (study 2)
- Evaluation (hr after challenge): 24, 48 and 72 hours
Challenge controls:
Control groups (no induction treatment)
Positive control substance(s):
no

Results and discussion

Positive control results:
Positive controls not performed.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
other: 1st study test group
Dose level:
50%
No. with + reactions:
3
Total no. in group:
10
Clinical observations:
slight erythema (score 1)
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group:
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
other: 1st study test group
Dose level:
50%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
none
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group:
Reading:
other: 3rd reading
Hours after challenge:
72
Group:
other: 1st study test group
Dose level:
50%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
none
Remarks on result:
other: Reading:
Reading:
1st reading
Hours after challenge:
24
Group:
other: 2nd study test group
Dose level:
50%
No. with + reactions:
1
Total no. in group:
12
Clinical observations:
slight erythema (score 1)
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group:
Reading:
2nd reading
Hours after challenge:
48
Group:
other: 2nd study test group
Dose level:
50%
No. with + reactions:
1
Total no. in group:
12
Clinical observations:
slight erythemy (score 1)
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group:
Reading:
other: 3rd reading
Hours after challenge:
72
Group:
other: 2nd study test group
Dose level:
50%
No. with + reactions:
0
Total no. in group:
12
Clinical observations:
none
Remarks on result:
other: Reading:

Any other information on results incl. tables

In the first study, 3/10 females exhibited a slight skin response (erythema score 1) 24 h after challenge, in the parallel test with formaldehyde 1/10 females exhibited a slight skin response (erythema score 1) 24 h after challenge, which can be interpreted as weak sensitizing potential.

In the second study using 12 female animals at a concentration of 50 % methanol, 1/12 exhibited a slight skin response (erythema score 1) 24 and 48 h after challenge which can be interpreted as a weak sensitising potential.

The intracutane inductions produced necroses and some open ulcerations in both studies.

In summary, the low number of 4/22 animals with slight erythema (score 1) gives no evidence of a notable sensitisation potential of methanol.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information