1-Dodecene, dimers

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

There were 5 key in vivo dermal sensitisation studies available for poly alpha olefins and their structural analogues.

 

A Buehler sensitisation study (Morris, 1995) was identified for dec-1-ene dimers, hydrogenated. Following a pilot study to determine the appropriate concentrations of test material to use in the induction and challenge phases, male and female Hartely guinea pigs were dermally treated with undiluted dec-1 -ene, dimers, hydrogenated once /week for 6 hours/exposure for three consecutive weeks.  Following a 2 week rest period, the test animals and a naïve control group were dermally challenged with 5 % test substance W/V in spectrum oil. The animals were scored for skin sensitising reactions at 24 and 48 hours following the challenge phase.  The primary challenge resulted in a grade 1 response, which was of less incidence and severity than the naïve control group.  Based on these results, it was determined that sensitization to the test material was not induced.

 

In a Magnusson and Kligman Maximization study for dec-1-ene, dimers, hydrogenated (Mallory, 1992), dec-1 -ene, homopolymer, hydrogenated administered intradermally to male and female Hartley Guinea Pigs at 5.0% V/V in mineral oil following an initial range finding test. Topical induction and challenge phases were conducted using 10% V/V test material in mineral oil. One week after the intradermal induction, treatment groups were induced by topical application of the test material for 48 hours. Fourteen days following topical induction, all animals received a challenge application at naïve sites. In addition to test material administration, a group of animals also received vehicle control and 1-chloro-2, 4 -dinitrobenzene (DNCB) as positive control. No signs of skin irritation, edema, or erythema were observed in any of the male or female treatment or vehicle control group animals throughout the study period. Animals that received the positive control 1-chloro-2,4-dintrobenzene (DNCB) exhibited a positive response. No other signs of clinical toxicity were noticed following administration of the test material. The individual and group mean body weights for both male and female guinea pigs were found to be similar to those of the vehicle controls through the study period. Based on these findings, dec-1 -ene, homopolymer, hydrogenated was not considered to be a dermal sensitizer in guinea pigs.

 

In a Magnusson and Kligman Maximization study for 1-decene, homopolymer, hydrogenated (Wilson and Brown, 1997), twenty guinea pigs were treated with 6 intradermal injections of the test material (two injections at 50% aqueous Freund’s Complete Adjuvant,  two injections of 100% test material, and two injections of 100% test material in 25% aqueous Freund’s Complete Adjuvant) on day 0.  Ten control group animals were also treated with 6 intradermal injections (two injections of 50% aqueous Freund’s Complete Adjuvant, two injections vehicle, and two injections of the vehicle in 25% aqueous Freund’s Complete Adjuvant). On test day 6, no irritation was observed so the test sites were treated with 0.5 ml of 10% sodium lauryl sulphate. On test day 7, each test group animal was treated with a topical application of the test material (vehicle for control group) for 48 hours. On test day 20, animals were challenged with 100% dec-1 -ene, homopolymer, hydrogenated via topical application. At challenge, two test group animals (10%) exhibited mild erythema to the test material. No positive responses were observed in the control group.  A rechallenge was conducted where all animals were exposed to 100% and 50% solutions of dec-1 -ene, homopolymer, hydrogenated. One (5%) of the test group animals (different from those that responded to the challenge) exhibited mild erythema when rechallanged topically to 100% of test material. In this study, dec-1 -ene, homopolymer, hydrogenated was not considered to be a dermal sensitizer in guinea pigs.

 

In a Magnusson and Kligman Maximization study for 1-decene, homopolymer, hydrogenated (Mallory, 1992),dec-1 -ene, was administered intradermally to male and female Hartley Guinea Pigs at 5.0% V/V in mineral oil following an initial range finding test. Topical induction and challenge phases were conducted using 10% V/V test material in mineral oil. One week after the intradermal induction, treatment groups were induced by topical application of the test material for 48 hours. Fourteen days following topical induction, all animals received a challenge application at naïve sites. In addition to test material administration, a group of animals also received vehicle control and 1-chloro-2, 4-dinitrobenzene (DNCB) as positive control. One female in the test group exhibited abnormal gait, flaccid body tone and tremors on day 9 of the study and then was found dead on day 10 of the study. The death was not considered treatment-related by the study authors. No signs of skin irritation, oedema, or erythema were observed in any of the male or female treatment or vehicle control group animals throughout the study period. Animals that received the positive control 1-chloro-2,4-dintrobenzene (DNCB) exhibited a positive response. No other signs of clinical toxicity were noticed following administration of the test material. The individual and group mean body weights for both male and female guinea pigs were found to be similar to those of the vehicle controls through the study period. dec-1 -ene, homopolymer, hydrogenated, injected intradermally at 5.0% and challenged topically as received, was not a dermal sensitiser in the guinea pig.

 

In a Local Lymph Node Assay (LLNA) with dec-1-ene, trimer, hydrogenated (Pooles, 2009), linealene dimer A-30H in propylene glycol (25 µL, 25%, 50%, and 100% dilutions) was administered once daily to the dorsal side of the ears of young adult CBA/Ca mice (4 females per treatment group) for three days.  On the sixth day of the study, mice received an injection in the tail vein of a³H-methylthymidine solution.  Lymph nodes were extracted, pooled and analyzed. Positive control samples, analyzed on a monthly basis by the testing laboratory, produced the appropriate response. There were no clinical signs of toxicity, mortality, or changes in body weight. Stimulation indices (SI) of 1.56, 1.89, and 3.54 were measured for the 25%, 50%, and 100% dilutions, respectively.  Based on a measured SI >3 for the undiluted dose, linealene dimer A-30H was considered by the study authors to produce a slight dermal sensitiser response in the LLNA. 

 

The overall weight of evidence presented by the sensitisation studies for poly alpha olefins indicates that these substances are not dermal sensitisers.  Four studies using established, reliable, and sensitive methods in guinea pigs produced no evidence of sensitising potential for these substances.  Results from the LLNA study, suggesting that poly alpha olefin substances have some dermal sensitizing potential, were considered suspect based on an absence of structural alerts and an established history of safe use in personal care products. Therefore, poly alpha olefins are not considered to be dermal sensitisers; classification and labelling for this endpoint is not warranted.

Short description of key information:
There were three read-across in vivo dermal sensitisation studies and one key study (all according or similar to OECD 406) using established, reliable, sensitive methods in guinea pigs that produced no evidence of sensitising potential for any of the poly alpha olefins tested. A read-across local lymph node assay (LLNA; OECD 429) also was identified that reported positive sensitising potential for the test substance. However, results from the LLNA study were considered suspect based on an absence of structural alerts and an established history of safe use in personal care products. Therefore, poly alpha olefins are not considered to be dermal sensitisers; classification and labelling for this endpoint is not warranted. Dec-1-ene, dimers, hydrogenated is not a dermal sensitiser and contains no chemical alerts for respiratory sensitisation.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Not expected to cause respiratory sensitisation based on results of skin sensitisation testing and an absence of reactive chemical alerts.

Short description of key information:
Not expected to cause respiratory sensitisation based on results of skin sensitisation testing and an absence of reactive chemical alerts.

Justification for classification or non-classification

Dec-1-ene, dimers, hydrogenated is not classified for skin sensitisation as defined by CLP EU Regulation 1272/2008 (GHS aligned) based on overall evaluation of five dermal sensitisation studies with poly alpha olefins. Dec-1-ene, dimers, hydrogenated is not expected to be a respiratory sensitizer based on results of skin sensitisation studies and an absence of reactive chemical alerts.