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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: only secondary literature, but sound abstract, according to OECD and EPA guidelines and GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2005
Report Date:
2005

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Qualifier:
according to
Guideline:
EPA OPPTS 870.2600 (Skin Sensitisation)
GLP compliance:
yes
Remarks:
no further data given
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Housing: 4 per cage
- Diet: ad libitum
- Water: ad libitum


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3 °C
- Humidity (%): 30 - 70 %
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 / 12

A total of 24 female CBA/Ca mice were divided into 6 groups consisting of 4 animals in each group. Groups included 1 control (vehicle) group and 5 test groups. Animals were housed 4 per cage in an environmentally controlled animal room with a room temperature of 22+/-3° C, relative humidity of 30 - 70%, a minimum of 15 air changes per hour, and a 12 hour light/dark cycle. Food and water were available ad libitum. The control group was treated with the vehicle only. Animals were checked at least once daily for signs of systemic toxicity and body weights were recorded prior to treatment and prior to injection with methyl thymidine.

Study design: in vivo (LLNA)

Vehicle:
other: 1:3 ethanol:diethyl phthalate
Concentration:
50, 25, 10, 5 and 2.5%
No. of animals per dose:
4
Details on study design:
study length: 3 days

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: LLNA
- Criteria used to consider a positive response: Test material
was regarded as a sensitizer in the LLNA if one or more concentrations of the test material elicited a
3-fold or greater increase in isotope incorporation relative to the vehicle control group (SI>/= 3.0).


TREATMENT PREPARATION AND ADMINISTRATION:
- A volume of approximately 25 ul of 5 different concentrations of test material (%v/v) in a vehicle of 1:3 ethanol:diethyl phthalate was applied topically to the dorsum of each ear lobe (left and right) on three consecutive days.
Positive control substance(s):
not specified
Statistics:
(EC3) was calculated by interpolating between two SI points using the following equation; EC3 = [(3 - d)/(b - d)] x (a - c) + c, where a = concentration with SI immediately above 3, b = SI of a, c = concentration with SI immediately below 3, and d = SI of c.

Results and discussion

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: 50% -> SI = 3.6 -> sensitization effects 25% -> SI = 1.3 -> no effects 10% -> SI = 1.0 -> no effects 5% -> SI = 1.2 -> no effects 2.5% -> SI = 1.6 -> no effects
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: 50% -> DPM per LN: 1206 25% -> DPM per LN: 443 10% -> DPM per LN: 315 5% -> DPM per LN: 398 2.5% -> DPM per LN: 512

Any other information on results incl. tables

Under the conditions of the test, the test material in ethanol:diethyl phthalate (1:3) was classified as a likely sensitizer with an EC3 value of 43.5% w/v or 10875 ug/cm² based on the classification scheme of Basketter 2000 and Gerberick, 2001.

The test material showed sensitization effects at 50% with a stimulation index of 3.6.

The test material was not a sensitizer at 25% with a stimulation index of 1.3.

The test material was not a sensitizer at 10% with a stimulation index of 1.0.

The test material was not a sensitizer at 5% with a stimulation index of 1.2.

The test material was not a sensitizer at 2.5% with a stimulation index of 1.6.

Applicant's summary and conclusion

Interpretation of results:
other: likely sensitising