Fatty acids, C16-18

Endpoint summary

Description of key information

Irritation / corrosion:
- skin: not irritating (OECD 404; Analogy CAS 57-10-3, CAS 57-11-4);
- eye: not irritating (OECD 405; Analogy CAS 57-10-3, CAS 57-11-4);

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vivo

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

29 Jan - 04 Feb 1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

1981

Deviations:

yes

Remarks:

occlusive dressing; no details on reading time points

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Version / remarks:

Commission Directive 84/449/EEC

Deviations:

yes

Remarks:

occlusive dressing; no details on reading time points

GLP compliance:

yes

Species:

rabbit

Strain:

other: Kleinrusse, Chbb: HM

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Fa. Thomae, Biberach, Germany
- Weight at study initiation: mean: 2452.5 g
- Housing: individually housed in rabbit batteries, Fa. Heinkel, Kuchen, Germany
- Diet: Zucht- /Haltungsdiät 20 ZH 5, Fa. Nohrlin GmbH, Bad Salzuflen, Germany, ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 1 week


ENVIRONMENTAL CONDITIONS
- Temperature (°C): approx. 20 - 21
- Humidity (%): approx. 45 - 50
- Photoperiod (hrs dark / hrs light): 12 / 12

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 0.5 g

Duration of treatment / exposure:

4 hours

Observation period:

3 days

Number of animals:

4 males

Details on study design:

TEST SITE
- Area of exposure: dorsal area
- Type of wrap if used: The substance was applied to the intact skin using a patch (2.5x2.5 cm), which was covered by a plastic foil using adhesive plasters and an acrylastic band aid.

SCORING SYSTEM: Draize Scoring System

Irritation parameter:

erythema score

Basis:

animal: #1, #2, #3 and #4

Time point:

other: mean over all reading time points

Score:

0

Max. score:

4

Reversibility:

other: reversibility not applicable

Remarks on result:

no indication of irritation

Irritation parameter:

edema score

Basis:

animal: #1, #2, #3 and #4

Time point:

other: mean over all reading time points

Score:

0

Max. score:

4

Reversibility:

other: reversibility not applicable

Remarks on result:

no indication of irritation

Irritation parameter:

erythema score

Basis:

animal:

Remarks:

#1, #2, #3, #4

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other:

Remarks:

no details on reading time points given

Irritation parameter:

edema score

Basis:

animal:

Remarks:

#1, #2, #3, #4

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other:

Remarks:

no details on reading time points given

Irritant / corrosive response data:

No skin reactions were observed.

Interpretation of results:

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

Conclusions:

CLP: not classified

Reference 2

Endpoint:

skin irritation: in vivo

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Test procedure according to national standard standard methods performed with the source substance CAS 57-11-4. In accordance to the ECHA guidance document "Practical guide: How to use alternatives to animal testing" (July 2016), the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Qualifier:

according to guideline

Guideline:

other: Patch test / Revised (1964) Federal Hazardous Substance Act

Deviations:

not specified

GLP compliance:

no

Species:

rabbit

Strain:

New Zealand White

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

0.5 mL

Duration of treatment / exposure:

24 hours

Observation period:

72 hours
Reading time points: 24 and 72 hours

Number of animals:

6

Details on study design:

Fur was removed from the back of each of six rabbits by clipping the saddle of the trunk area. One area of skin was abraded by making minor incisions with a hypodermic needle. 0.5 mL of test material was applied to 1 in2 gauze patches. The patches were placed on both intact skin and abraded skin of each rabbit and secured with adhesive tape, rubber dental damming secured with staples, and gauze wound loosely around the trunk. The animals were then immobilized for 24 hours in wooden stocks. After 24 hours, the patches were removed and the skin cleaned by gently sponging with a moistened towel. The skin was examined immediately after removal of the patches (24 hours reading) and again at 72 hours. At each examination the skin was scored for presence and severity of erythema/eschar formation and edema formation.

Irritation parameter:

erythema score

Basis:

mean

Remarks:

out of all 6 animals

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

other: intact sites

Irritation parameter:

edema score

Basis:

mean

Remarks:

out of all 6 animals

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

other: intact sites

Irritant / corrosive response data:

No signs of skin irritation were observed on intact or abraded sites at either scoring time point.

Material (0.5 ml) was applied via a one-inch-square surgical gauze patch to intact and abraded-skin sites. Patches were held in place for 24 hours. Reactions were scored immediately after patch removal and two days later (72 hours).

Table 1: Scores for Skin Irritation

Observation time	Rabbit no.
	43		44		45		46		47		48
	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema
24 h	0	0	0	0	0	0	0	0	0	0	0	0
48 h	No experimental data available; for calculation of mean scores, the 48 h values were assumed to be the same as those at 24 h (worst case assumption)
72 h	0	0	0	0	0	0	0	0	0	0	0	0

Table 2: Calculation of mean scores

	Rabbit no.
	43		44		45		46		47		48
	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema
Mean value 24 + 48 + 72 h*	0	0	0	0	0	0	0	0	0	0	0	0

*No 48 h data are available: for calculation of mean scores, the 48 h values were assumed to be the same as those at 24 h (worst case assumption: persistence of effects seen at 24 h over 48 h).

Interpretation of results:

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

Conclusions:

CLP: not classified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Reference 1

Endpoint:

eye irritation: in vivo

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Basic data given

Qualifier:

according to guideline

Guideline:

other: Regulation for the Enforcement of the Federal Hazardous Substances Act (Revised, Federal Register, September 17, 1964)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Title 49, Department of Transportation Code of Federal Regulation, Section 173, 240 (Federal Register, February 12, 1973)

Deviations:

no

GLP compliance:

no

Species:

rabbit

Strain:

not specified

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Duration of treatment / exposure:

single application

Observation period (in vivo):

72 h

Number of animals or in vitro replicates:

6

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24/48/72 h

Score:

0.2

Max. score:

3

Reversibility:

fully reversible within: 72 h

Remarks on result:

other: effects noted in 2/6 animals

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: no effects noted

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

2

Reversibility:

other: no effects noted

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

3

Reversibility:

other: no effects noted

Mild conjunctival erythema was shown in 2 of 6 animals at 24 and 48 hours while all signs of irritation hat subsided completely in 72 hours.

Interpretation of results:

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

Conclusions:

CLP: not classified

Reference 2

Endpoint:

eye irritation: in vivo

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

26 Feb - 04 Mar 1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP - Guideline study, tested with the source substance CAS 57-10-3. In accordance to the ECHA guidance document "Practical guide 6: How to report read-across and categories (March 2010)", the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

other: Kleinrussen Chbb

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: HM / Fa. Thomae, Biberach, Germany
- Weight at study initiation: ca. 2640 g
- Housing: individually (Fa. Heinkel, Kuchen, Germany)
- Diet (ad libitum): Altromin diet 2023, Altromin GmbH, Lage, Germany
- Water (ad libitum): community tap water; ad libitum
- Acclimation period: at least 7 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): ca. 20 - 21
- Humidity (%): 45 - 55
- Photoperiod (hrs dark / hrs light): 12 / 12

Vehicle:

unchanged (no vehicle)

Controls:

other: left eyes of the same animals were used for control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 g

Duration of treatment / exposure:

permanent, without washing-off

Observation period (in vivo):

3 days (since only minor scores were observed that fully returned to normal within 3 days the experiment was cancelled due to animal welfare reasons; therefore the reduced observation period does not represent a deviation to the OECD guideline)

Number of animals or in vitro replicates:

4

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

4 animals

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: no effects

Irritation parameter:

iris score

Basis:

mean

Remarks:

4 animals

Time point:

24/48/72 h

Score:

0

Max. score:

2

Reversibility:

other: no effects

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

mean

Remarks:

4 animals

Time point:

24/48/72 h

Score:

0.3

Max. score:

3

Reversibility:

fully reversible within: 48 h

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

4 animals

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: no effects

Irritation parameter:

other: exudation

Basis:

mean

Remarks:

4 animals

Time point:

24/48/72 h

Score:

0

Max. score:

3

Reversibility:

other: no effects

Tab.1: Conjunctival reactions after application of 0.1 g Edenor C16 - 92/94 (undiluted, permanent, 4 male rabbits)

Time point after application	Redness		Chemosis		Exudation
	Individual data	Average	Individual data	Average	Individual data	Average
60 min	1 / 1 / 1 / 1	1.00	0 / 1 / 1 /1	0.75	0 / 0 / 0 / 1	0.25
6 h	1 / 2/ 1 / 1	1.25	0 / 0 / 0 / 0	0	2 / 0 / 0 / 1	0.75
24 h	1 / 1 / 1 / 1	1.00	0 / 0 / 0 / 0	0	0 / 0 / 0 / 0	0
48 h	0 / 0 / 0 / 0	0	0 / 0 / 0 / 0	0	0 / 0 / 0 / 0	0
72 h	0 / 0 / 0 / 0	0	0 / 0 / 0 / 0	0	0 / 0 / 0 / 0	0

Animal No. (from left to right) 790, 796, 798, 799

Reactions on the cornea and iris were not observed. The conjunctival reactions were slight and disappeared totally within 48 hours. Palmitic acid is not irritating to eyes / mucosa under the test conditions.

Interpretation of results:

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

Conclusions:

CLP: not classified

Reference 3

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

other information

Study period:

29 Apr 1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline available

Principles of method if other than guideline:

The test item was applied to the chorioallantoic membrane (CAM) of a fertilized hen´s egg for 5 minutes. Afterwards, the CAM was evaluated for the development of lysis, hemorrhage, and coagulation to evaluate eye irritation.

GLP compliance:

yes

Species:

other: chicken egg

Strain:

other: White Leghorn

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Horst Geflügelzucht, Leverkusen, Germany
- Age at study initiation: 10 days
- Housing: The eggs were kept in an incubator before study inititation.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 37.6 ± 0.5 °C
- Humidity (%): ca. 50 - 60%

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 300 µl

Duration of treatment / exposure:

5 min

Observation period (in vivo):

not applicable

Number of animals or in vitro replicates:

Initial test: 3 fertilized eggs
Main study: 6 fertilized eggs

Details on study design:

TEST SYSTEM: HET-CAM (Hen´s egg test-chorioallantoic membrane): Fertilized eggs are incubated for 9 days. On the 10th day, the eggshield is opened and the chorioallantoic membrane is exposed to the test item.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The CAM was rinsed with physiological saline solution.
- Time after start of exposure: 5 min

SCORING SYSTEM: The scoring system differentiates between light, moderate and severe effects which are allocated in accordance to the reactions after exposure to the reference substance Texapon ASV in the concentrations of 0.5, 1 and 5%.

Irritation parameter:

other: hemorrhage

Remarks:

mean out of all 9 eggs

Run / experiment:

5 min

Vehicle controls validity:

not specified

Negative controls validity:

not specified

Positive controls validity:

not specified

Remarks on result:

other: No signs of hemorrhage were observed.

Irritation parameter:

other: coagulation

Remarks:

mean out of all 9 eggs

Run / experiment:

5 min

Vehicle controls validity:

not specified

Negative controls validity:

not specified

Positive controls validity:

not specified

Remarks on result:

other: No coagulation was observed.

Irritation parameter:

other: lysis

Remarks:

mean out of all 9 eggs

Run / experiment:

5 min

Vehicle controls validity:

not specified

Negative controls validity:

not specified

Positive controls validity:

not specified

Remarks on result:

other: No signs of hyperemia were observed.

Other effects / acceptance of results:

The test item did not induce hemorrhage, coagulation or lysis. Therefore, Aversin KFC is considered to be not irritating.

Interpretation of results:

other: not irritating

Conclusions:

Data are conclusive but not sufficient for classification.

Executive summary:

Regarding the CLP guidance document, negative results of the HET-CAM are not conclusive for a non-classification.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin

Due to the lack of reliable data with fatty acids C16-18 on skin irritation, studies with two of the main constituents, C16 fatty acid (palmitic acid) and C18 fatty acid (stearic acid), are used for hazard assessment. Since fatty acids C16-18, palmitic acid, and stearic acid belong to the same category based on structural and toxicological properties, this approach can be regarded as scientifically justified. Thus, read-across is performed based on a category approach (for details refer to IUCLID chapter 13).

Skin irritation by palmitic acid was evaluated in a study performed under GLP according to OECD guideline 404 with the exception, that the test was performed under occlusive condition (Kästner, 1988). Four Kleinrussen rabbits received an application of 0.5 g palmitic acid to the shaved skin under occlusion for 4 hours. The readings 24, 48, and 72 hours after application did not reveal any signs of irritation, thus resulting in mean scores of 0 for erythema and edema, respectively. As a consequence, test was cancelled due to welfare reasons. Based on the results, palmitic acid can be regarded as not irritating to skin.

In a study with human subjects, palmitic acid and 19 other substances were investigated with a closed epicutanous test. 10 µl of palmitic acid at a concentration of 50% was applied to the back of the volunteers for 24 hours using a Large Finn Chamber (Matthies, 1988). The reactions were scored for edema, erythema, scaling and fissures 1, 6, 24, 48, 72 and 144 hours after application. As result, for all readings the score 0 was found.

Skin irritation by stearic acid was evaluated in a study performed in accordance with federal guidelines (International Bio-Research, 1974). 0.5 mL of stearic acid was applied to the abraded skin of 6 New Zealand White rabbits under occlusion for 24 hours.at 24 and 72 hours after application revealed no signs of irritation. Although a longer application under occlusion than suggested according to actual guidelines, the resulting scores are 0, both for erythema and edema, respectively. Based on this, stearic acid can be regarded as not irritating to skin.

 

 

Eye

Due to the lack of reliable data with fatty acids C16-18 on eye irritation, studies with two of the main constituents, C16 fatty acid (palmitic acid) and C18 fatty acid (stearic acid), are used for hazard assessment. Since fatty acids C16-18, palmitic acid, and stearic acid belong to the same category based on structural and toxicological properties, this approach can be regarded as scientifically justified. Thus, read-across is performed based on a category approach (for details refer to IUCLID chapter 13).

Eye irritation by palmitic acid was analyzed in a study performed in accordance with GLP and according to OECD guideline 405 (Kästner, 1988). 0.1 g of palmitic was instilled into the rtights eyes of four Kleinrussen rabbits while the untreated left eyes served as control. The reactions were examined 1, 6, 24, 48, and 72 hour after administration and resulted in mean scores of 0, 0, 0.3, 0 and 0 for corneal opacity, iris, conjunctival redness and chemosis, and exudation, respectively. Since all signs were subsided on day three after instillation, the study was cancelled on that day due to animal welfare reasons. Based on the findings, palmitic acid can be regarded as not irritating to eyes.

In a published study performed according to national guidelines, stearic acid was instilled into the eyes of six rabbits (Briggs et al., 1976). Mild conjunctival erythema was found in 2 animals at 24 and 48 hours while all signs of irritation hat subsided completely in 72 hours. Thus, a mean score of 0.2 for conjunctival erythema could be calculated. Based on the results, stearic acid can be regarded as not irritating to eyes.

Justification for classification or non-classification

The substance may contain lauric acid (C12), which is classified as eye damage Cat 1. The specific concentration limit for the lauric acid is established as 73.6% based on reliable experimental data. According to CLP (1272/2008/EC) classification criteria for irritation/corrosion, fatty acids C16 -18 do not fulfill the criteria for classification and thus a non-classification is warranted for this endpoint, as the concentration of C12 is lower than 73.6%.