Fatty acids, C14-18 and C18-unsatd., branched and linear, 2-ethylhexyl esters

Skin irritation / corrosion

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Administrative data

Endpoint:

skin irritation: in vivo

Type of 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: Read Across Category Target Substance Endpoint Record

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Test material

Test material information

Constituent 1

Test material form:

liquid

Results and discussion

In vivo

Results

Remarks on result:

no indication of irritation

Any other information on results incl. tables

Table 1: Results from key studies on source chemicals of the category for skin irritation and corrosion tests

ID#	CAS	Skin irritation or skin corrosion
Fatty acids, C8-16, 2- ethylhexyl esters	135800-37-2	Experimental result: Not irritating
Fatty acids, coco, 2-ethylhexyl esters	92044-87-6	Experimental result: Not irritating
2-Ethylhexyl palmitate	29806-73-3	Experimental result: Not irritating
Fatty acids, C16-18 and C18-unsatd., 2- ethylhexyl esters	85049-37-2	No data
Fatty acids, C16-18, 2-ethylhexyl esters	91031-48-0	No data
2-Ethylhexyloleate	26399-02-0	Experimental result: Not irritating
2-Ethylhexylstearate	22047-49-0	Experimental result: Not irritating

 

According to the current literature, esterase enzymes were present into the skin of different mammalian species (as human, rodents or minpigs). These enzymes, as carboxylesterase, hydrolyzed different substrates as xenobiotic or different ester as fatty acids esters (C. Jewell, 2007; J.J. Prusakiewicz, 2006). Based on this principle, when applied on skin, the source and the target substances are expected to be substrates of these carboxylesterase. They are hydrolyzed into fatty acids and alcohols. In the case that the products of hydrolysis could across the dermal barrier to reach systemic system, they have the same behavior as oral ingestion. The potential toxicity should be bring by these hydrolyzed products.

According to their very low solubility in water and their log Kow values, these substances are not expected to be strong acid or basic substances. However, based on the probable pH values of these substances, acid reserve value is necessary to assess potential irritation/corrosion effect (Young J.R and M.J. How, 1994). Despite no acid reserve value, and regarding the potential nonacid or basic pH of these substances, no local adverse effect, as irritation or corrosion, is expected in skin for the target substance..

 

Based on the available key studies, the members of the category were considered as not irritating when applied on skin. Hence, the target substance was not classified for skin irritation according to CLP criteria and the category approach.

 

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

According to the results from experimental study performed on the substances of the LCAE Category, the category substances did not led to irritation when applied on rabbit skin. Hence, according to the CLP criteria and the category approach, the registered substance was not classified for Skin Irritation.

Executive summary:

According to the Regulation (EC) NO. 1907/2006, Annex XI, 1.5, A Read-Across Category for Long Chain Fatty Acid was performed in order to provide informations on the Isostearate Ethyl Hexyl.

This category was based on common and shared physico-chemical and structural properties as:

-       common functional group,

-       common precursors and the likehood of common impurities as well as common breakdown products via biological processes, which are chemically structurally similar, and

-       constant pattern in the changing of the potency of the properties across the category.

The fatty acids linked with 2-ethylhexyl esters have a common metabolic fate in organisms as glycolytic and fatty acid pathways after first hydrolysis step which led in breakdown products. The common toxicokinetic properties and behavior are expected due to the constant pattern (ethylhexyl esters and the fatty acid chain). The toxicological profiles between the members of the category are expected to be the same.

Several studies were performed to assess skin irritation for members of the category. They are considered as reliable (GLP compliant, method equivalent or similar to OECD 404 guideline method). Rabbits were used for these experimental studies. Shaved or clipped skin were treated under semi occlusive condition for 72 hours and observations were performed at differents timepoints (24, 48 and 72 hours) according to Draize scheme. No reaction or slight reaction was observed (recovery within 24 hours).

According to the results from experimental study performed on the substances of the LCAE Category, the category substances did not led to irritation when applied on rabbit skin. Hence, according to the CLP criteria and the category approach, the registered substance was not classified for Skin Irritation.