Fatty acids, C8-18 and C18-unsatd., zinc salts

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2022

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Zinc dioctanoate

EC Number:

209-156-6

EC Name:

Zinc dioctanoate

Cas Number:

557-09-5

Molecular formula:

C16H30O4Zn

IUPAC Name:

zinc(II) octanoate

Constituent 2

Reference substance name:

Zinc decanoate

EC Number:

235-909-3

EC Name:

Zinc decanoate

Molecular formula:

C10H20O2.1/2Zn

IUPAC Name:

zinc(II) decanoate

Constituent 3

Reference substance name:

Zinc dilaurate

EC Number:

219-518-5

EC Name:

Zinc dilaurate

Cas Number:

2452-01-9

Molecular formula:

C12H24O2.1/2Zn

IUPAC Name:

zinc(II) dodecanoate

Constituent 4

Reference substance name:

Zinc dimyristate

EC Number:

240-369-7

EC Name:

Zinc dimyristate

Cas Number:

16260-27-8

Molecular formula:

C28H54O4Zn

IUPAC Name:

zinc(II) tetradecanoate

Constituent 5

Reference substance name:

Zinc dipalmitate

EC Number:

225-652-5

EC Name:

Zinc dipalmitate

Cas Number:

4991-47-3

Molecular formula:

C16H32O2.1/2Zn

IUPAC Name:

zinc(II) hexadecanoate

Constituent 6

Reference substance name:

Zinc distearate

EC Number:

209-151-9

EC Name:

Zinc distearate

Cas Number:

557-05-1

Molecular formula:

C18H36O2.1/2Zn

IUPAC Name:

zinc(II) octadecanoate

Constituent 7

Reference substance name:

Zinc dioleate

EC Number:

209-154-5

EC Name:

Zinc dioleate

Cas Number:

557-07-3

Molecular formula:

C18H34O2.1/2Zn

IUPAC Name:

zinc(II) 9-octadecenoate

Constituent 8

Reference substance name:

Zinc dilinoleate

EC Number:

235-870-2

EC Name:

Zinc dilinoleate

Cas Number:

13014-44-3

Molecular formula:

C36H62O4Zn

IUPAC Name:

zinc(II) 9,12-octadecdienoate

Test material form:

solid: bulk

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Species and strain : Sam;New Zealand White Rabbit
Microbiological grade : Specific Pathogen Free(SPF)
Sex : Female
Breeder : SAMTAKO BIO KOREA (105, Seorang-ro, Osan-si, Gyeonggi-do, Republic of Korea, 18100)
Supplier : Yeongbio (388, Dunchon-daero, Jungwon-gu, Seongnam-si, Gyeonggido, Republic of Korea, 13391)


Step Age(week old) Number of animals A range of body weight(g)
At receipt 10 4 1745.4~1815.2
At application 11 3 2018.4~2203.7

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

Group Dose volume (g) Number of animals Animal number
1 0.5 3 1~3


The 0.5 g of test substance was applicated per site in accordance with “Testing Guidelines for Studies of Chemicals, Chapter 5 Health impact test field, Section 3 Acute Dermal Irritation/Corrosion” National Institute of Environmental Research Notification.

Duration of treatment / exposure:

3 minutes, 1 hour, 4 hours

Observation period:

24, 48, and 72 hours

Number of animals:

3

Details on study design:

3.2. Application of Test Substance
3.2.1. Justification for route of application
The dermal route was selected to investigate the skin irritation and corrosivity of the test substance.

3.2.2. Method
Onto the one site of back, 0.5 g/site of prepared test substance was applied to a small area of dermal and covered with a gauze patch moistened with a corn oil, which was held in place with non-irritating tape(Tegaderm, 3M_USA). The entire trunk of the animals was wrapped with elastic bandages(Coban, 3M). At the end of the exposure period, the dressing was removed and residual test substance was carefully washed away with corn oil. The adjacent area to the test site was served as a control.

3.2.2.1. Initial test (In vivo dermal irritation/corrosion test using one animal)
A single animal was administered sequentially first. The first patch was removed after 3 minutes of application, and the second patch was applied to a different site for 1 hour due to no serious dermal irritations observed after the first patch removal. No serious dermal irritation was observed after the second patch removal, and the third patch was applied to a different site for 4 hours.

3.2.2.2. Confirmatory test (In vivo dermal irritation test with additional two animals)
No skin corrosion was observed in the initial test. Therefore, the confirmatory test was conducted on two additional animals, each with one test substance patch, for an exposure period of 4 hours.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

not specified

Results 2

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.7

Max. score:

4

Reversibility:

fully reversible

Results 3

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible

Results 4

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible

Irritant / corrosive response data:

No skin corrosion was observed after the first(applied for 3 minutes) and second(applied for 1 hour) and third(applied for 4 hours) application in the initial test conducted on one animal. Therefore, the confirmatory test with two animals were carried out. No skin corrosion was observed in all animals after the 4 hours application.

The skin irritation scores of erythema/eschar were calculated as “0.7”, “1.0”, “1.0”. The skin irritation scores of oedema was calculated as “0.0” in all animals.
The skin irritation scores for erythema/eschar and oedema calculated based on the results at 24, 48 and 72 hours are as follows.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

This study was conducted to confirm the Globally Harmonized System of Classification and Labelling of Chemical (GHS) category through the calculation of Skin Irritation Scores based on the acute dermal irritation and corrosivity of the test substance, Fatty acids, C8-18 and C18-unsatd., zinc salts, following a single skin application to female New Zealand White rabbits. Mortality, clinical signs and body weights, skin irritations and corrosivity were evaluated after the application of the test substance.
Mortality related to the test substance was not observed in all animals.
Slight exfoliation was observed in animal No. 2 and animal No. 3 in the confirmation test. This clinical sign was fully reversible on the 12 day after patch removal.
Body weight changes related to the test substance were not observed in all animals.
Corrosion was not observed in all animals up to 72 hours after application of the test substance.
The skin irritation scores of erythema/eschar were calculated as “0.7”, “1.0”, “1.0”. The skin irritation scores of oedema was calculated as “0.0” in all animals.
Therefore, the test substance was considered to be non-irritants and the 14-day observation period required to establish reversibility was not applied.
The above results show that when applying the test substance, Fatty acids, C8-18 and C18-unsatd., zinc salts to under the conditions of this study, considered to be “Not classified” according to the GHS category.