Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets



Category name:
Poly-alpha olefins (PAOs)

Justifications and discussions

Category definition:
Poly-alpha olefins (PAOs)
Category rationale:
The Poly Alpha Olefins category covers products that are made from the polymerization/oligomerization of alpha olefins. The carbon number for the category typically ranges from C16 to C60 but may go as high as 84. Products in this category may be hydrogenated to remove remaining double bonds. The phys-chem and environmental fate properties of the category members will be similar or if they change they will change in a predictable fashion. For example, the water solubility is expected to decrease as the carbon number increases. Environmental effects will behave in a similar manner, acting via non-polar narcosis. It is expected that the low water solubility of the products will limit the potential aquatic toxicity. With regard to mammalian endpoints, category members are liquids of low volatility. Skin contact therefore represents the primary route of exposure with inhalation expected to be a minor source of exposure. The category members differ from one-another only in carbon chain length. The differing carbon numbers, are not expected to have a significant effect on the mammalian toxicity. It can therefore, be assumed that products meeting the applicable domain will behave in a similar manner and that use of read-across is valid.