Registration Dossier

Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study performed under GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report Date:
2001

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
GLP compliance:
yes
Type of study:
guinea pig maximisation test

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid
Details on test material:
Batch number: 00925

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: David Hall Limited, Burton-on-Trent, Staffordshire, UK.
- Age at study initiation: 8-12 weeks old
- Weight at study initiation: 300-328g
- Housing: Housed individually or in pairs in solid-floor polypropylene cages furnished with woodflakes.
- Diet: Guinea Pig FD1 Diet ad libitum
- Water: Tap water ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17 - 23
- Humidity (%): 30 - 70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 hours light / 12 hours dark

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
arachis oil
Concentration / amount:
- Intradermal induction: 1% v/v in arachis oil BP
- Topical induction: undiluted as supplied
- Topical challenge: 25% and 50% in arachis oil BP
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
arachis oil
Concentration / amount:
- Intradermal induction: 1% v/v in arachis oil BP
- Topical induction: undiluted as supplied
- Topical challenge: 25% and 50% in arachis oil BP
No. of animals per dose:
- 10 animals were treated with test material.
- 5 animals served as a control.
- 6 animals were used in the range-finding study.
Details on study design:
1) Induction:
Prior to treatment on day 0, an area (40mm x 60mm) on the shoulder region of each test animal was clipped free of hair. Three injections were made on each side of the mid-line in a 20mm x 40 mm area, these injections were:

i) Freund's Complete Adjuvant plus distilled water in the ratio 1:1
ii) 1% v/v formulation of the test substance in arachis oil BP
iii) 1% v/v formulation of the test material in a 1:1 preparation of Freund's Complete Adjuvant plus distilled water.

On day 7, the same intradermally treated area was clipped free of hair and treated with a topical application of undiluted test material. A filter paper patch (Whatman No. 4: 40mm x 20mm) was saturated with the undiluted test material and applied to the shaven skin and held in place with a strip of surgical adhesive tape covered with a length of overlapping aluminium foil. This patch and foil was secured with a strip of elastic adhesive bandage wound around the torso of each test animal. This occlusive dressing was kept in place for 48 hours.

Intradermal induction of the control animals was carried out in an identical fashion to that used for the test material treated animals, except that the test material was omitted from the injections. The control animals received the following injections:
i) Freund's Complete Adjuvant plus distilled water in the ratio 1:1
ii) arachis oil BP
iii) 50% formulation of the vehicle in a 1:1 preparation of Freund's Complete Adjuvant plus distilled water.

2) Challenge:
The test animals were challenged 21 days after the initial induction. Prior to the challenge, an area (50mm x 70mm) on both flanks of each test animal was clipped free of hair. A Whatman filter paper patch (20mm x 20mm) was saturated with the test material at the maximum non-irritant concentration (50% v/v in arachis oil BP) and applied to clipped area on the right flank of each test animal. This was held in place with adhesive surgical tape. In addition, the test material at 25% v/v in arachis oil was similarly applied to the left flank of the clipped area. Both patches were occluded with an overlapping length of aluminium foil and secured with a strip of elastic adhesive bandage would around the torso of each animal.

After 24 hours, the dressing was removed and challenge sites were swabbed with cotton wool saturated with diethyl ether to remove residual test material. Prior to the 24-hour observation, the flanks were clipped to remove regrown hair. At 24 and 48 hours after challenge dressing removal, the degree of erythema and oedema was assessed.
Challenge controls:
Received the same challenge as the test material treated animals.
Positive control substance(s):
yes
Remarks:
Positive controls were not performed concurrently with this study.

Results and discussion

Positive control results:
Positive controls (using the substances, 2-Mercaptobenzothiazole and alpha-hexylcinnamaldehyde) were not run concurrently with this study. Historic positive controls have been conducted and these gave the expected results and demonstrate the validity of this test method.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
25%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 25%. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
25%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 25%. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
50%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 50%. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
50%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 50%. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
25%
No. with + reactions:
0
Total no. in group:
5
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 25%. No with. + reactions: 0.0. Total no. in groups: 5.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
25%
No. with + reactions:
0
Total no. in group:
5
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 25%. No with. + reactions: 0.0. Total no. in groups: 5.0.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
50%
No. with + reactions:
0
Total no. in group:
5
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 50%. No with. + reactions: 0.0. Total no. in groups: 5.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
50%
No. with + reactions:
0
Total no. in group:
5
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 50%. No with. + reactions: 0.0. Total no. in groups: 5.0.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
Under the conditions of this study, ethyl methyl carbonate has been shown to be not sensitising to guinea pig skin.