Fatty acids, tall-oil, esters with ethylene glycol

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 Aug - 28 Sep 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

adopted Jul 1992

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

Version / remarks:

Mar 2003

Deviations:

not specified

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: EC No 440/2008, part B. Skin Sensitization: Guinea-Pig Maximization Test (GPMT)

Version / remarks:

May 2008

Deviations:

not specified

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: JMAFF Guidelines

Version / remarks:

2000

Deviations:

not specified

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The guinea pig maximization test was selected since the available alternative in vitro tests for skin sensitization are not applicable for the test item due to its intrinsic properties. The guinea pig maximization test was selected as animal test since the test item is a fatty acid and the Local Lymph Node Assay as preferred animal alternative has shown to provide false positive results for fatty acids.

Test material

Test material information

Constituent 1

Reference substance name:

Fatty acids, tall-oil, esters with ethylene glycol

EC Number:

269-130-5

EC Name:

Fatty acids, tall-oil, esters with ethylene glycol

Cas Number:

68187-85-9

Molecular formula:

C38H66O4 C38H64O4 C40H68O4 C40H70O4 C38H68O4

IUPAC Name:

2-[(9Z)-octadec-9-enoyloxy]ethyl (9Z)-octadec-9-enoate; 2-[(9Z)-octadec-9-enoyloxy]ethyl (9Z,12Z)-octadeca-9,12-dienoate; 2-[(9Z,12Z)-octadeca-9,12-dienoyloxy]ethyl (9Z,12Z)-octadeca-9,12-dienoate

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River France, L’Arbresle, France
- Microbiological status of animals, when known: SPF
- Age at study initiation: approximately 4 - 5 weeks
- Weight at study initiation: 283 - 330 g
- Housing: Animals were group housed (up to 5 animals of the same sex and same dosing group together) in labeled Noryl cages (Tecniplast; 74 cm x 54 cm x 25 cm height) containing sterilized sawdust as bedding material (Lignocel S 8-15, JRS - J.Rettenmaier & Söhne GmbH + CO. KG, Rosenberg, Germany) equipped with water bottles.
- Diet: Complete maintenance diet for guinea pigs (MS-H, SSNIFF® Spezialdiäten GmbH, Soest, Germany), ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 - 23
- Humidity (%): 43 - 73
- Air changes (per hr): ten or greater
- Photoperiod (hrs dark / hrs light): 12/12

- IN-LIFE DATES: From: 10 Aug 2018 To: 28 Sep 2018

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal

Vehicle:

unchanged (no vehicle)

Concentration / amount:

100%

Day(s)/duration:

single injection on Day 1

Adequacy of induction:

non-irritant substance, but skin pre-treated with 10% SDS

Induction 2

Route:

epicutaneous, semiocclusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

100%

Day(s)/duration:

Applied on Day 7, 48 h

Adequacy of induction:

non-irritant substance, but skin pre-treated with 10% SDS

Challenge

No.:

#1

Route:

epicutaneous, semiocclusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

100%

Day(s)/duration:

1 day

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

5 (control) and 10 (treatment group)

Details on study design:

RANGE FINDING TESTS:
To determine a suitable concentration for the intradermal induction in the main study, a series of four test item concentrations (10, 20, 50 and 100%) was selected. A total of 2 female guinea pigs each received two different concentrations (50 and 100%) in duplicate (0.1 mL/site) in the clipped scapular region. The injection sites were assessed for irritation 24 and 48 hours after treatment. The degree of erythema at the injection sites was recorded 24 and 48 h after injection.
To determine a suitable concentration for the epicutaneous induction in the main study, a series of four test item concentrations was tested, the highest concentration being the undiluted test item. Two different concentrations were applied (0.5 mL each per animal to the clipped flank, using Metalline patches (2x3 cm) mounted on Medical tape which were held in place with Micropore tape and subsequently Coban elastic bandage. The animals receiving intradermal injections were treated with the lowest concentrations and two other animals with the highest concentrations. The degree of erythema at the injection sites was recorded 24 and 48 h after injection.
Based on the results, the test item concentration selected for the main study was the undiluted test item for the intradermal and epidermal induction and for the challenge. No signs of irritation were observed to the undiluted test item dosed epidermally and therefore, the test site of all animals of the main study were treated with 10% SDS approximately 24 hours before the epidermal induction, to provoke a mild inflammatory reaction.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2 (intradermal and epicutaneous, respectively)
- Exposure period: single injection (intradermal) and 48 h (epicutaneous)
- Test groups:
Intradermal (3 pairs of injections):
Injection 1: a 1:1 mixture (v/v) FCA/water
Injection 2: unchanged (100%) test material
Injection 3: unchanged (100%) test material in a 1:1 mixture (v/v) FCA/water
Epicutaneous: the undiluted test substance
- Control group:
Intradermal (3 pairs of injections):
Injection 1: a 1:1 mixture (v/v) FCA/water
Injection 2: corn oil
Injection 3: corn oil in a 1:1 mixture (v/v) FCA/water
Epicutaneous: blank patch
- Site: shoulder region (intradermal and epicutaneous)
- Frequency of applications: Day 0 (intradermal) and Day 7 (epicutaneous)
- Duration: Days 0 - 7
- Concentrations: intradermal and epicutaneous: undiluted test material

B. CHALLENGE EXPOSURE
- No. of exposures: 1 (challenge)
- Day(s) of challenge: 21
- Exposure period: 24 h
- Test groups: test substance in arachis oil BP and test substance only
- Site: one flank (test substance only), other flank (vehicle)
- Concentrations: undiluted test material
- Evaluation: 24 and 48 h after patch removal

Positive control substance(s):

no

Results and discussion

Positive control results:

A reliability check is carried out at regular intervals to check the sensitivity of the test system and the reliability of the experimental techniques as used by the testing facility. In this study, performed in July 2017, females of the Dunkin Hartley guinea pig (from Charles River France, L’Arbresle, France) were checked for the sensitivity to alpha-hexylcinnamaldehyde, technical grade.
The skin reactions observed in 10/10 animals in response to the 50% test item concentration in the challenge phase were considered indicative of sensitisation, based on the absence of any response in the control animals. These results lead to a sensitisation rate of 100 percent to the 50% concentration. From these results, it was concluded that the female guinea pig of the Dunkin Hartley strain is an appropriate animal model for the performance of studies designed to evaluate the sensitizing potential of a test item in a Maximization type of test.

In vivo (non-LLNA)

Results

Results 1

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

Induction: undiluted (intradermal + epicutaneous); Challenge: undiluted (epicutaneous)

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

none

Results 2

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

Induction: 0% (intradermal + epicutaneous); Challenge: undiluted

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

none

Results 3

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

Induction: undiluted (intradermal + epicutaneous); Challenge: undiluted (epicutaneous)

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

none

Results 4

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

Induction: 0% (intradermal + epicutaneous); Challenge: undiluted

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

none

Results 5

Group:

positive control

Remarks on result:

positive indication of skin sensitisation

Any other information on results incl. tables

Table 1: Induction readings

Control Animals
Animal Number	Intradermal injections (readings Day 3)						Epidermal exposure (readings Day 10)
	1:1 Mixture of FCA and water for injection		Corn oil		1:1 Mixture of FCA and corn oil		Corn oil
	Erythema	Signs of necrosis (Ø mm)	Erythema	Signs of necrosis (Ø mm)	Erythema	Signs of necrosis (Ø mm)	Erythema	Oedema
41	0		0		0		1	0
42		5	0		0		1	0
43		2	0		0		1	0
44		2	0		0		1	0
45		3	0		0		1	0
Experimental Animals
Animal Number	Intradermal injections (readings Day 3)						Epidermal exposure (readings Day 10)
	1:1 Mixture of FCA and water for injection		Undiluted test item		1:1 Mixture of FCA and undiluted test item		Undiluted test item
	Erythema	Signs of necrosis (Ø mm)	Erythema	Signs of necrosis (Ø mm)	Erythema	Signs of necrosis (Ø mm)	Erythema	Oedema
46		1	0			5	1	0
47	1		1			3	2	0
48	1		1			2	2	0
49	1		1			3	1s	0
50		3	0			5	1s	0
51		2	0		0		2s	1
52		2	0		0		1	1
53		4		2		6	1	0
54	1		1			2	2	1
55		2		3		2	1s	1

FCA = Freunds' Complete Adjuvant, s. = Scaliness.

Grading erythema:

0 = No erythema

1 = Slight erythema (barely perceptible)

2 = Well-defined erythema

Grading Oedema:

0 = No oedema

1 = Slight oedema (barely perceptible)

Table 2: Challenge readings

Animal number	Day 24		Day 25		Comments
	Undiluted test item	Vehicle	Undiluted test item	Vehicle
Control
41	0	0	0	0
42	0	0	0	0
43	0	0	0	0
44	0	0	0	0
45	0	0	0	0
Experimental
46	0	0	0	0	not sensitized
47	0	0	0	0	not sensitized
48	0	0	0	0	not sensitized
49	0	0	0	0	not sensitized
50	0	0	0	0	not sensitized
51	0	0	0	0	not sensitized
52	0	0	0	0	not sensitized
53	0	0	0	0	not sensitized
54	0	0	0	0	not sensitized
55	0	0	0	0	not sensitized

Grading challenge reactions:

0 = No visible change

Applicant's summary and conclusion

Interpretation of results:

other: CLP/EU GHS criteria not met, no classification required according to Regulation (EC) No 1272/2008