Registration Dossier

Administrative data

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

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Additional information

Skin

Due to the lack of reliable data with bw fatty acids (hydrogenated tallow, distn. residues) 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 (hydrogenated tallow, distn. residues), 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 bw fatty acids (hydrogenated tallow, distn. residues) 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 (hydrogenated tallow, distn. residues), 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.

Due to the similar structural and toxicological properties of the members within the category including fatty acids (hydrogenated tallow, distn. residues) and two of its main constituents palmitic acid and stearic acid, fatty acids (hydrogenated tallow, distn. residues) are not irritating to skin and eyes.

Justification for classification or non-classification

The substance may contain few of lauric acid (C12), which is classified as R41/eye damage Cat 1. The specific concentration limit for the lauric acid is established as 70% based on a reliable experimental data. According to DPD (1999/45/EC) or CLP (1272/2008/EC) classification criteria for irritation/corrosion, fatty acids (hydrogenated tallow, distn. residues) 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 70%.

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