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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:
other: Study well documented, meets generally accepted scientific principles, acceptable for assessment.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Mice were exposed by dermal route (epicutaneous, open) to ETU. After induction and challenge phase, the sensibilisant power of ETU was studied.
GLP compliance:
yes
Type of study:
mouse ear swelling test

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Other name = Ethylenethiourea (ETU)
ETU was obtained from the Aldrich Chemical Corporation Corp., Milwaukee, WI.
Lot #PC081687/B01 ; Purity > 99% (HPLC)

In vivo test system

Test animals

Species:
mouse
Strain:
B6C3F1
Sex:
female
Details on test animals and environmental conditions:
no data

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
epicutaneous, open
Vehicle:
other: ethylene glycol
Concentration / amount:
Induction : 1.0%, 3.0%, 10.0% ETU
Challenge : 10% ETU
Challengeopen allclose all
Route:
epicutaneous, open
Vehicle:
other: ethylene glycol
Concentration / amount:
Induction : 1.0%, 3.0%, 10.0% ETU
Challenge : 10% ETU
No. of animals per dose:
8 mice per group
Details on study design:
RANGE FINDING TESTS:
Primary irritancy studies indicated that all concentrations of ETU tested (up to 30%) were non-irritating.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 1
- Exposure period: 5 consecutive days
- Site: Dorsal surface site
- Frequency of applications: in continuously
- Concentrations: 1.0%, 3.0% or 10.0% ETU

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: no data
- Exposure period: no data
- Site: on the dorsal and ventral sites on the left ear.
- Concentrations: 10% ETU
- Evaluation (hr after challenge): 24 and 48hr


OTHER: Between Induction exposure and challenge exposure, there were 7 days.
Site preparation included intradermal injection of Freud's complete adjuvant in some mice.
The irritancy response was determined by monitoring the extravasation of 125 I- bovine serum albumin into the treated area. The contact hypersensitivity response was determined by monitoring the infiltration of 125 I-iododeoxyuridine laabeled cells into the challenge site in addition to the mouse ear swelling test.
Challenge controls:
yes, vehicle control. see table.
Positive control substance(s):
yes
Remarks:
DNFB

Results and discussion

Positive control results:
The positive response with 0.5% DNFB was observed 24 hr after challenge.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
10%
No. with + reactions:
0
Total no. in group:
8
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 10%. No with. + reactions: 0.0. Total no. in groups: 8.0.
Reading:
1st reading
Hours after challenge:
48
Group:
test group
Dose level:
10%
No. with + reactions:
0
Total no. in group:
8
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 48.0. Group: test group. Dose level: 10%. No with. + reactions: 0.0. Total no. in groups: 8.0.

Any other information on results incl. tables

There were no treatment-related effects on survival or body weights. There was no evidence of skin irritation in the form of erythma or edema in any of the treatment groups. No statistically significant or dose-related hypersensitivity response was observed in mice sensitized with 1%, 3% or 10% ETU and challenge with 10% ETU.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
Under these experimental conditions, no statistically significant or dose-dependent contact hypersensitivity responses to ETU were observed in mice following dermal exposure.
Executive summary:

ETU was tested in his sensibility with a mouse ear swelling test. The induction was made with 1.0%, 3.0%, 10.0% ETU, and the challenge with 10% ETU. There were no statistically significant or dose-dependent contact hypersensitivity responses with ETU.