Registration Dossier

Administrative data

Description of key information

A test in accordance of OECD guideline n°429 was performed to assess the skin sensitization potential of the test item 4-phenoxyphenol in the CBA/J strain mouse following topical application to the dorsal surface of the ear. The stimulation increase (SI) calculated by pooled approach was 1.76, 2.27 and 2.27 for the treated groups at 20%, 40% and 60%, respectively. Therefore, the EC1.4 cannot be determined due to the absence of SI value lower than 1.4. However based on a dose-response effect (the SI is increasing with the percentage of the substance) the test substance has to be considered as sensitizing for skin. The 4 -Paraphenoxyphenol has to be classified as a sensitizer in Category 1, H317. No sub-category can be specify.

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:
2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
no
GLP compliance:
yes
Type of study:
mouse local lymph node assay (LLNA)
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Batch No.of test material: Batch N°20180328
- Expiration date of the lot/batch: March 2019

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature
Species:
mouse
Strain:
CBA:J
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Elevage Janvier Labs (F-53941 Le Genest Saint Isle)
- Females nulliparous and non-pregnant: Yes
- Age at study initiation: 8 weeks old
- Weight at study initiation: Yes
- Housing: individually housed
- Diet (ad libitum): ENVIGO 2016
- Water (ad libitum): tap water from public distribution system (Microbiological and chemical analyses of the water were carried out once every six months)
- Acclimation period: Yes (five days)

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19°C to 25°C
- Humidity (%): 30% to 70%
- Air changes (per hr): ten changes per hour
- Photoperiod (hrs dark / hrs light): 12h dark/ 12h day
Vehicle:
acetone/olive oil (4:1 v/v)
Concentration:
Pre-screen test : 60%
Main study : 60% ; 40% ; 25% ; 0% (vehicule)
No. of animals per dose:
Pre-screen test : one mouse
Main study : four mice
Details on study design:
PRE-SCREEN TESTS: Yes
- Application : 25 μL
- Application : the dorsal surface of each ear
- Frequence : three consecutive days (Days 1, 2, 3).
- Observation ay 1 to day 6. The bodyweight of the mouce was recorded on Day 1 (prior to dosing) and on Day 6.

MAIN STUDY
- Application : 25 μL
- Application : the dorsal surface of each ear
- Frequence : three consecutive days (Days 1, 2, 3).
- Observation : clinical and mortality : Days 1, 2, 3, 4, 5, 6 ; Bodyweights : day 1 and day 6 ; Ear Thickness measurement and recording of local reactions : Yes
- Euthanized: Day 6 (end of the test) with sodium pentobarbital (Dolethal®). The draining auricular lymph nodes from the four mice were excised.


Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)
Positive control results:
Valid
Key result
Parameter:
SI
Value:
ca. 1.76
Test group / Remarks:
20%
Key result
Parameter:
SI
Value:
ca. 2.27
Test group / Remarks:
40%
Key result
Parameter:
SI
Value:
ca. 2.27
Test group / Remarks:
60%
Cellular proliferation data / Observations:
CELLULAR PROLIFERATION DATA
- A single cell suspension of the lymph node cells of 4 mice was prepared.
- The lymphocyte cells were counted using a cell counter (Beckman Coulter Z2).

DETAILS ON STIMULATION INDEX CALCULATION
- The proliferation response of lymph node cells was expressed as the number of lymphocytes per lymph node and as the ratio of lymphocytes into lymph node cells of test nodes relative to that recorded for the control nodes (Stimulation Index).

EC1.4 CALCULATION
- The EC1.4 value (theoretical concentration resulting in a SI value of 1.4) was determined by linear interpolation of points on the dose-response curve, immediately above and below the 1.4-fold threshold.

CLINICAL OBSERVATIONS:
- Preliminary screening study : No mortality and no signs of systemic toxicity. No cutaneous reactions.
- Main test : No mortality and no signs of systemic toxicity (test and control animals)
- the test item has to be considered as not excessively irritant at these concentrations in accordance with the OECD criteria

BODY WEIGHTS
- Bodyweight changes of the test animals between Day 1 and Day 6 were comparable to those observed in the corresponding control group animals over the same period

Table : Cell count, stimulation index and calculation of EC1.4 (main study)

 Groups Test item  Cell count/ group (*106 cells/ml)  Stimulation INdex (SI)  Result EC 1.4 value 
 1 0% (vehicule)  50.97  n.a  n.a  n.a 
 2 20%  89.62  1.76  Positive  n.a
 3 40%  115.60  2.27  Positive  n.a 
 4 60%  115.80  2.27  Positive  n.a 

Table: Individual ear Thickness and irritation level (main study)

 

 Groups Test item Animals

Day 1

eat thickness (mm) 

 Day 3

eat thickness (mm)

Day 6

eat thickness (mm)

% of ear thickness increased/ day 1 

 irritation level

 1

Vehicule n°1

0.20

0.19 

0.21 

5.0 

 -

 

 Vehicule n°2

0.20 

0.19 

0.21 

5.0 

 -

 

 Vehicule n°3

0.19 

0.19 

0.19 

0.0 

 -

 

 Vehicule n°4

0.21 

0.20 

0.19 

-9.5 

 -

 

 Mean

0.20 

0.19 

0.20 

0.1 

 -

 

 Standard deviation

0.01 

0.01 

0.01 

6.8 

 -

 2

20% - n°1 

0.18 

0.20 

0.22 

22.2 

 Slightly irritant

 

20% - n°2 

0.19 

0.20 

0.20 

5.3 

 Slightly irritant

 

 20% - n°3

 0.19

0.20 

0.21 

10.5 

Slightly irritant 

 

 20% - n°4

0.18 

0.19 

0.22 

22.2 

Slightly irritant 

 

 Mean

0.19 

0.20 

0.21 

15.1 

Slightly irritant 

 

 Standard deviation

0.01 

0.01 

0.01 

8.5 

Slightly irritant 

 3

40% - n°1 

0.20 

0.21 

0.23 

15.0 

Slightly irritant 

 

 40% - n°2

0.21 

0.21 

0.24 

14.3 

Slightly irritant 

 

 40% - n°3

0.19 

0.20 

0.24 

26.3 

Slightly irritant 
   40% - n°4 0.19  0.20  0.22  15.8  Slightly irritant 
   Mean 0.20  0.21  0.23  17.8  Slightly irritant 
   Standard deviation 0.01  0.01  0.01  5.7  Slightly irritant 
 4 60% - n°1  0.20  0.20  0.22  10.0  Slightly irritant 
  60% - n°2 0.20  0.20  0.22  10.0  Slightly irritant 
  60% - n°3  0.19  0.19  0.23  21.1  Slightly irritant 
   60% - n°4 0.19  0.20  0.22  15.8  Slightly irritant 
   Mean 0.20  0.20  0.22  14.2  Slightly irritant 
   Standard deviation 0.01  0.01  0.01  5.3 Slightly irritant 
Interpretation of results:
Category 1 (skin sensitising) based on GHS criteria
Conclusions:
In view of these results, under these experimental conditions, the test item Paraphenoxyphenol has to be classified as a sensitiser in Category 1, in accordance with the Regulation EC No. 1272/2008 on classification, labelling and packaging of substances and mixtures.
Executive summary:

A test in accordance of OECD guideline n°429 was performed to assess the skin sensitization potential of the test item Paraphenoxyphenol in the CBA/J strain mouse following topical application to the dorsal surface of the ear.

Three groups of four animals were treated for the three consecutive days (D1, D2, D3) with 50 μL (25μL per ear) of the test item diluted in Acetone/olive oil (4:1 v/v) (AOO) at concentrations of 20%,

40% and 60%. A further group of four animals was treated with AOO On D6, the proliferation of lymphocytes in the draining auricular lymph nodes was determined by cell counting.

No mortality and no sign of systemic toxicity were noted in the treated and control animals during the test. No increase in ear weight was recorded at the concentrations of 20%, 40% and 60 %. Therefore, the test item has to be considered as not excessively irritant at these concentrations in accordance with the OECD criteria.

The stimulation increase (SI) calculated by pooled approach was 1.76, 2.27 and 2.27 for the treated groups at 20%, 40% and 60%, respectively. Therefore, the EC1.4 can not be determined due to the absence of SI value lower than 1.4.

In view of these results, under these experimental conditions, the test item Paraphenoxyphenol has to be classified as a sensitiser in Category 1, in accordance with the Regulation EC No. 1272/2008 on classification, labelling and packaging of substances and mixtures.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (sensitising)

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

In view of these results, under these experimental conditions, the test item 4 -phenoxyphenol has to be classified as a sensitizer in Category 1, in accordance with the Regulation EC No. 1272/2008 on classification, labelling and packaging of substances and mixtures.