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Description of key information

Tested in this study according to OECD test guideline no. 429 and GLP conditions the test item was not a skin sensitizer.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 4 APR 2006 to 25 APR 2006
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study (OECD TG 429)
Qualifier:
according to guideline
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
no
GLP compliance:
yes
Type of study:
mouse local lymph node assay (LLNA)
Species:
mouse
Strain:
CBA
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Netherlands BV, Horst, The Netherlands
- Age at study initiation: 6-12 weeks
- Housing: Individually in Macrolon Type I cages with wire mesh top and granulated sooft wood bedding
- Diet: Pelleted standard diet (provided by Harlan Winkelmann GmbH, Borchen, Germany); ad libitum
- Water: Community tap water from Rossdorf, ad libitum
- Acclimation period: yes, but duration not mentioned

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22+/-3
- Humidity (%): 27-70
- Photoperiod (hrs dark / hrs light): 12/12
Vehicle:
dimethyl sulphoxide
Concentration:
0, 6.25, 12.5 and 25% (w/v)
No. of animals per dose:
4 females per dose group
2 females in the pre-test
Details on study design:
RANGE FINDING TESTS:
- Compound solubility: DMSO was selected because it was more suitable than any other vehicles
- 25% (w/v) was the highest technically applicable concentration
- Irritation: no local irritation or systemic toxicity after single application of test item concentrations of 3.125 or 6.25% (w/v); irritating effects could not be detected due to yellow staining at concentrations of 12.5 or 25% (w/v)
- Lymph node proliferation response: no data

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: LLNA
- Criteria used to consider a positive response:
1: exposure to at least one concentration of the test item resulted in an incorporation of 3H-methyl thymidine at least 3-fold or greater than that recorded in control mice as indicated by the stimulation index
2: data are compatible with a conventional dose response, although allowance must be made for either local toxicity or immunological suppression

TREATMENT PREPARATION AND ADMINISTRATION:
- individual preparation of weight volume dilutions using a magnetic stirrer as homogenizer
- test item preparations were made feshly before each dosing occasion
- 25 µl were spread over the entire dorsal surface of each ear lobe once daily for three consecutive days
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)
Statistics:
- calculations of mean values and standard deviations for body weight
Positive control results:
Stimulation indices of 6.08, 13.59 and 26.41 were determined with the positive control item at concentrations of 5%, 10% and 25% (w/v), respectively, in acetone:olive oil, 4:1 (v/v). An EC3 value could not be calculated, since all SI's are above 3.
Key result
Parameter:
SI
Value:
ca. 1.6
Test group / Remarks:
6.25% test item:
Remarks on result:
other: Stimulation indices (SI) were all below 3. The following SI were calculated: 6.25% test item: 1.60 12,5% test item: 1.51 25% test item: 1.71
Key result
Parameter:
SI
Value:
ca. 1.51
Test group / Remarks:
12,5% test item:
Key result
Parameter:
SI
Value:
ca. 1.71
Test group / Remarks:
25% test item:
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: Background of measurement: 41.88 - 106.47; mean: 74.18 (was taken for calculations) control group: 6591.41 6.25% test item: 10487.6 12,5% test item: 9930.64 25% test item: 11220.8

The animals did not show any clinical signs during the course of the study and no cases of mortality were observed. Calculation of the EC3 value was not performed because no test concentration produced a SI of 3 or higher.

Test item
concentration
% (w/v)

Group

Measurement
DPM

Calculation

Result

DPM-BG

a)

number of
lymph
nodes

DPM per

lymph node
b)

S.I.

---

BG I

41.88

---

---

---

---

---

BG II

106.47

---

---

---

---

---

CG 1

6591 .41

6517.2

8

814.7

 

6.25

TG 2

10487.60

10413.4

8

1301.7

1.60

12.5

TG 3

9930.64

9856.5

8

1232.1

1.51

25

TG 4

11220.80

11146.6

8

1393.3

1.71

BG = Background (1 ml 5% trichloroacetic acid) in duplicate

CG = Control Group

TG = Test Group

S.I. = Stimulation Index

a)      = The mean value was taken from the figures BG I and BG II

b)      = Since the lymph nodes of the animals of a dose group were pooled,DPM/node was determined by dividing the measured value by the number oflymph nodes pooled

Interpretation of results:
GHS criteria not met
Remarks:
Regulation (EC) no 1272/2008
Conclusions:
Tested in this study according to OECD test guideline no. 429 and GLP conditions the test item was not a skin sensitizer.
Executive summary:

In the study the test item suspended in DMSO was assessed for its possible contact allergenic potential.

For this purpose a local lymph node assay was performed using test item concentrations of 6.25, 12.5 and 25%.

The animals did not show any clinical signs during the course of the study and no cases of mortality were observed. Due to the yellow colour of the test item local irritation reactions such as ear redness could not be detected at the mid and high dose.

In this study Stimulation Indices (S.I.) of 1.60, 1.51 and 1.71 were determined with the test item at concentrations of 6.25, 12.5 and 25% (w/v) in DMSO, respectively.

The test item was not a skin sensitiser in this assay.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

No classification - Tested in this study according to OECD test guideline no. 429 and GLP conditions the test item was not a skin sensitizer.