Oligomerisation products of 1-tetradecene and 1-dodecene, hydrogenated, C24-56 fraction

Endpoint summary

Description of key information

Two read-across dermal irritation studies (OECD 404) were identified from decene trimer hydrogenated and 1-dodecene dimer with 1-decene, hydrogenated. Neither test material was identified as a dermal irritant in rabbits following 4 hour semi-occlusive exposures.
One key eye irritation study (OEC 405) was identified, in which dec-1-ene, dimers, hydrogenated was not found to be irritating to the eyes of rabbits in this study.

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

Eight key studies were identified which evaluated the dermal irritation potential of poly alpha olefins and their structural analogues. However, only two of the eight strictly adhered to the current OECD 404 guidelines (4 hour exposure, semi-occlusive conditions) with mean scores for erythema and oedema averaged over 24, 48, and 72 hours. These two studies were conducted with decene trimer hydrogenated and 1-dodecene dimer with 1-decene, hydrogenated. The remaining studies, using occlusive methods and/or skin contact times exceeding 4 hours duration, although considered less reliable since the exposure conditions were more stringent than guideline, produced similar results to the semi-occluded studies conducted for 4 hours. Only one of the studies using occlusive methods and an extended exposure time reported mean erythema or oedema scores exceeding the thresholds for classification (dec-1-ene dimers, hydrogenated), the remaining did not. The two studies on decene trimer hydrogenated and 1-dodecene dimer with 1-decene, hydrogenated are discussed in further detail below and are the presented in the table above because they were the only studies used in the evaluation of classification and labelling. An additional two supporting studies specifically on dec-1-ene, dimers, hydrogenated also are presented in the table above; however, they are not discussed below because they do not meet current OECD 404 guidelines.

In the study with decene trimer hydrogenated (Pooles, 2009b), 3 young adult New Zealand White Rabbits were dermally exposed to 0.5 mL of undiluted Linealene A-30H (semi-occluded patch with 2.5 square centimeter area) for 4 hours. Animals were observed for 7 days and irritation was scored by the method of Draize. There were no treatment related changes in body weight. Dermal irritation occurred in one rabbit with very slight erythema and oedema through 72 hours. At 72 hours the skin had lost its elasticity and flexibility. There was slight desquamation noted on day 7 in one rabbit. There were no effects observed in the other two rabbits. The mean erythema and oedema score were both reported as 0.33.

 

In the study with 1-dodecene dimer with 1-decene, hydrogenated (Dougherty, 1989c), dermal application of 0.5 mL 1 -dodecene, dimer with 1 -decene to 6 young adult female New Zealand White rabbits produced mean erythema scores of 0.57 and 0.91 and mean oedema scores of 0.00 and 0.00 (intact and abraded skin, respectively). Flaky skin was observed in some animals up to day 7, but was absent by day 14. No other signs of clinical toxicity were reported.

 

Based on the weight of evidence from the aforementioned dermal irritation studies, poly alpha olefin substances, including dec-1-ene, dimers, hydrogenated, are not considered to be skin irritants and do not meet the criteria for classification and labelling for this endpoint.

 

There was no evidence of corrosive effects in any of these investigations.

One key eye irritation study was identified for dec-1-ene , dimers, hydrogenated (Doyle, 1988). In this primary eye irritation study, 6 female New Zealand White rabbits were instilled with 0.1 mL of dec-1 -ene, dimer, hydrogenated in the right eye. The left eye served as control. Treated eyes were not rinsed or washed. Following test chemical instillation, the animals were observed for any gross signs of eye irritation at 24, 48 and 72 hours. Scoring of irritative eye effects was performed using the Draize method. There was no evidence of corneal lesions or changes to the iris 72 hours post test chemical instillation. Conjunctival changes such as Grade 1 erythema were observed 24 hours after instillation in the eyes of 4/6 rabbits tested and in all rabbits 48-hours post application. By the 72-hour period, only 2 rabbits exhibited Grade 1 erythema. Conjunctival swelling (score of 1-2) was observed in 4/6 animals at the 48-hour period, but by 72 hours, the effect had lessened in severity and was seen only in one animal. Based on the results from this study, dec-1-ene, dimers, hydrogenated is not considered to be an ocular irritant and is therefore not classified or labelled for this endpoint.

Justification for classification or non-classification

Dec-1-ene, dimers, hydrogenated does not meet the criteria for classification and labelling as a skin irritant under EU Dangerous Substances Directive 67/548/EEC or CLP EU Regulation 1272/2008 based on evaluation of the overall mean erythema and oedema scores from skin irritation studies with structural analogues.

 

Dec-1-ene, dimers, hydrogenated does not meet the criteria for classification and labelling as an eye irritant as defined by EU Dangerous Substances Directive 67/548/EEC or CLP EU Regulation 1272/2008 based on read-across studies to structural analogues which were not irritating to the eyes of rabbits.