4-phenoxyphenol

Endpoint summary

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

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

Qualifier:

according to guideline

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.