Registration Dossier

Administrative data

Description of key information

RA-S CAS 16260-09-6 and CAS 13276-08-9, skin irritation (OECD 404): not irritating
RA-S CAS 16260-09-6 and CAS 13276-08-9, eye irritation (OECD 405): not irritating

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)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

There is no data available on the skin and eye irritation potential of (Z)-N-octadecyldocos-13-enamide (CAS 10094-45-8). In order to fulfil the standard information requirements set out in Annex VIII, 8.1 and 8.2, and in accordance with Annex XI, 1.5 of Regulation (EC) No 1907/2006, read-across from structurally related substances is conducted.

A detailed justification for the analogue approach is provided in the technical dossier (see IUCLID sections 7.1 and 13).

 

Skin irritation

Reliable studies investigating the skin irritation potential are available for the structurally related substances (Z)-N-octadec-9-enylhexadecan-1-amide (CAS 16260-09-6) and N-octadecylstearamide (CAS 13276-08-9), which are used for read-across based on the analogue approach.

The skin irritation potential of (Z)-N-octadec-9-enylhexadecan-1-amide (CAS 16260-09-6) was investigated in a GLP-compliant study performed according to OECD 404 (Thouin, 1986). The shaved skin of 3 female New Zealand White rabbits was exposed to test substance moistened with 0.5 mL water for 4 h under semi-occlusive conditions. The skin of the contralateral flank remained untreated and served as control. Evaluation of skin reactions (erythema and edema) was performed 1, 24, 48 and 72 h after removal of the dressing. At the 1 h reading time point, 2 animals showed slight erythema which was fully reversible within the following 24 h. No further dermal effects were observed in any of the animals at the remaining reading time points. The mean erythema and edema scores after 24, 48 and 72 h were 0 for each individual animal. Based on these results, the test substance was not considered to be irritating to skin.

In a skin irritation study with N-octadecyl stearamide (CAS 13276-08-9) according to OECD 404 performed under identical conditions as described above, neither skin reactions (erythema and edema) nor any systemic effects were observed 1, 24, 48 and 72 h after epicutaneous exposure to the test substance under semiocclusive conditions in 3 female New Zealand White rabbits (Thouin, 1986). The mean erythema and edema scores after 24, 48 and 72 h were 0 for each individual animal. Therefore, the test substance was demonstrated to be not skin irritating.

Based on the available data on skin irritation of the structural analogues, it may be concluded that (Z)-N-octadecyldocos-13-enamide (CAS 10094-45-8) is not irritating to skin, either.

 

Eye irritation

Reliable studies on eye irritation are available for the structurally related substances (Z)-N-octadec-9-enylhexadecan-1-amide (CAS 16260-09-6) and N-octadecylstearamide (CAS 13276-08-9), which are used for read-across based on the analogue approach.

An eye irritation study in compliance with OECD 405 and GLP was performed with (Z)-N-octadec-9-enylhexadecan-1-amide (CAS 16260-09-6) (Mulder, 1986). The undiluted test material (90 mg equivalent to ca. 0.1 mL) was placed into the conjunctival sac of one eye of 3 female New Zealand White rabbits each. The other eye remained untreated and served as control. The eyes were examined and scored 100 min, 24, 48 and 72 h as well as 7 and 14 days after test substance application. At the first observation time (100 min after instillation), hyperaemia of the blood vessels of the conjunctivae, affecting the eye lids and the scleral conjunctivae, was observed in all animals, as well as obvious swelling of the eyelids. Increased lacrimation was also observed in all animals at this time. Treatment of the eyes with fluorescein 24 h after substance installation revealed 20-25% corneal epithelial damage, which was fully reversible 3 days after treatment. At the 24 h reading time point, injection of the capillaries in the iris was observed in all animals, as well as deepened rugae in 1/3 animals; but in all animals the iris still reacted to light. In the animal with the deepened rugae, the iris effects disappeared within the next 24 h, while in the other 2 animals the injection of capillaries was still present at the 48 and 72 h reading time point. Slight conjunctival swelling persisted in all animals until 72 h after treatment, while slight redness was still observable on Day 7 of the observation period. Fourteen days after treatment, all adverse ocular effects had fully disappeared in the animals. The mean iris, conjunctivae and chemosis scores of the reading time points 24, 48 and 72 h were 0.3/0.7/1, 1.3/2/1.7 and 1.3/1.3/1.3 for the 3 individual animals, respectively. For cornea, the mean score was 0 in each individual animal at the 24, 48 and 72 h reading time points. Therefore, the test substance does not have to be considered as irritating to the eye.

In an eye irritation study with N-octadecylstearamide (CAS 13276-08-9) according to OECD 405 performed under identical conditions as described above, installation of the test substance into one eye of 3 female New Zealand White rabbits each caused hyperaemia of blood vessels of the conjunctivae, affecting the eyelids and the scleral conjunctivae, in all animals at the 1-h reading time point (Mulder, 1986). At the same time point, the eye lids were also slightly to moderately swollen and increased lacrimation was observed in 2/3 animals. The swelling disappeared in all animals within the next 24 to 48 hours, whereas slight redness persisted for 2 to 4 days. On Day 7 of the observation period, conjunctival effects were fully reversible in all animals. Treatment of the eyes with fluorescein 24 h after instillation of the test substance revealed 5% corneal epithelial damage in 1/3 animals, which was fully reversible on Day 3 of the observation period. Apart from this effect, no adverse effects on the cornea and the iris were observed in any of the rabbits during the entire observation period. The mean conjunctivae and chemosis scores of the reading time points 24, 48 and 72 h were 0.7/1/1 and 0/0/0.3 for the 3 individual animals, respectively. For cornea and iris, the mean scores were 0 in each individual animal at the 24, 48 and 72 h reading time points. Therefore, the test substance was not considered to be an eye irritant.

Based on the available data on eye irritation of the structural analogues, it is anticipated that (Z)-N-octadecyldocos-13-enamide (CAS 10094-45-8) does not exert an eye irritation potential, either.


Justification for selection of skin irritation / corrosion endpoint:
There are two studies available investigating the skin irritation potential of two structurally related substances. No study was selected, since both studies are considered to be equivalent key studies regarding to their reliability, quality of dose descriptor and time of study implementation.

Justification for selection of eye irritation endpoint:
There are two studies available investigating the eye irritation potential of two structurally related substances. No study was selected, since both studies are considered to be equivalent key studies regarding to their reliability, quality of dose descriptor and time of study implementation.

Justification for classification or non-classification

The available data on skin and eye irritation of (Z)-N-octadec-9-enylhexadecan-1-amide (CAS 16260-09-6) and N-octadecylstearamide (CAS 13276-08-9), which are structurally related substances to (Z)-N-octadecyldocos-13-enamide (CAS 10094-45-8) according to the criteria of Regulation (EC) No 1907/2006, Annex XI, 1.5, do not meet the criteria for classification according to Regulation (EC) No 1272/2008 or Directive 67/548/EEC; therefore, (Z)-N-octadecyldocos-13-enamide (CAS 10094-45-8) is not expected to exert a skin and eye irritation potential, either, and the data are conclusive but not sufficient for classification.