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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:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Justification for type of information:
Data is from Peer reviewed journal

Data source

Reference
Reference Type:
publication
Title:
Guinea Pig Maximization Test for Trichloroethylene and Its Metabolites
Author:
TANG XIAO-JIANG, LI LAI-YU, HUANG JIAN-XUN, AND DENG YING-YU
Year:
2002
Bibliographic source:
BIOMEDICAL AND ENVIRONMENTAL SCIENCES 15, 113-118 (2002)

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: as mentioned below
Principles of method if other than guideline:
A modified guinea pig maximization test (GPMT) was adopted.
GLP compliance:
not specified
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
Modified guinea pig maximization test (GPMT) was sufficient to classify the substance.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline
Details on test material:
- Name of test material: 2,2,2-Trichloroethane-1,1-diol (Chloral hydrate)
- Molecular formula: C2-H3-Cl3-O2
- Molecular weight: 165.4026g/mol
- Smiles notation: C(C(O)O)(Cl)(Cl)Cl
- InChl: RNFNDJAIBTYOQL-UHFFFAOYSA-N
- Substance type: Organic
- Physical state: Solid
Specific details on test material used for the study:
- Name of test material: 2,2,2-Trichloroethane-1,1-diol (Chloral hydrate)
- Molecular formula: C2-H3-Cl3-O2
- Molecular weight: 165.4026g/mol
- Smiles notation: C(C(O)O)(Cl)(Cl)Cl
- InChl: RNFNDJAIBTYOQL-UHFFFAOYSA-N
- Substance type: Organic
- Physical state: Solid

In vivo test system

Test animals

Species:
guinea pig
Strain:
other: FMMU
Sex:
not specified
Details on test animals and environmental conditions:
Source: Medical laboratory animal center (China).
Weight at study initiation: 300-350g
- Housing: Housed in an animal rooms.
- Diet (e.g. ad libitum): Standard guinea pig diet and Fresh vegetable
- Water (e.g. ad libitum): Tap water
- Acclimation period: One week
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23°C±1.5 °C
- Humidity (%): 55% ±10%
- Air changes (per hr): No data available
- Photoperiod (hrs dark / hrs light): 12 h day/night cycle



Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
water
Concentration / amount:
Induction: Intradermal concentration: 1%
Topical concentration: 5%
Challenge topical concentration : 2%
Challengeopen allclose all
Route:
epicutaneous, open
Vehicle:
water
Concentration / amount:
Induction: Intradermal concentration: 1%
Topical concentration: 5%
Challenge topical concentration : 2%
No. of animals per dose:
14 animals
Details on study design:
Details on study design
RANGE FINDING TESTS: Yes, primary irritation studies were performed before the start of induction and challenge phase.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period:
- Test groups: 7 groups
- Control group: 6
- Site: Dorsal skin of scapular region
- Frequency of applications: 3
- Duration: 21 days
- Concentrations:
Intradermal : 1%
Topical concentration: 5%

CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge:
- Exposure period: 24 hrs
- Test groups: 7 groups
- Control group: 6
- Site: Dorsal skin of scapular region
- Concentrations: 2%
- Evaluation (hr after challenge): 24 hrs and 48 hrs

Challenge controls:
No data available
Positive control substance(s):
not specified

Results and discussion

Positive control results:
No data available

In vivo (non-LLNA)

Results
Key result
Reading:
1st reading
Hours after challenge:
48
Group:
test group
Dose level:
2%
No. with + reactions:
0
Total no. in group:
14
Clinical observations:
None of the animals exhibited positive sensitization
Remarks on result:
no indication of skin sensitisation

Any other information on results incl. tables

Allergenic reaction observed in animal groups were graded as follows:

                 0: No reaction

                 1: Scattered mild redness

                 2: Moderate and diffuse redness

                 3: intensive erythema and swelling

Chloral hydrate was expected to have weak sensitization potential as per the study. However, since the number of animals with positive reaction were 0, chloral hydrate has been considered to be not sensitizing.

Applicant's summary and conclusion

Interpretation of results:
other: not sensitising
Conclusions:
Chloral hydrate was expected to have weak sensitization potential as per the study. However, since the number of animals with positive reaction were 0, chloral hydrate has been considered to be not sensitising.
Executive summary:

Skin sensitizing reaction was performed in guinea pigs usingGuinea pig maximisation test. 3-4 guinea pigs were used for primary irritation studies. Later on induction and challenge exposure were performed on 7 groups with 10-14 animals.

For Induction, dorsal skin in the scapular region was shaved and after 24 hrs 3 intradermal injections were injected. Control animals were supplied with vehicle only.

After intradermal induction, animals were challenged by topical application of test agent by closed patch test and observed for 24 hrs and 48 hrs. Based on percentage of animals sensitized the grading of allergenicity was calculated.

Therefore, from the above experiment chloralhydrate (302-17-0) was found to be not sensitising to guinea pig.