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Category name:
Xylenes - LOA

Justifications and discussions

Category definition:
Xylenes
Category rationale:
The Xylenes category covers streams that have a carbon number distribution that is predominantly C8. All of the streams in this category are almost entirely aromatic. Companies importing streams will need to confirm that such streams meet the chemical description and are in domain. The category also covers reaction masses that conform to the compositional limits outlined below.

It is reasonable to assume that the phys-chem and environmental fate properties of the category members will be very similar due to the small spread of carbon numbers. Environmental effects will behave in a similar manner, acting via narcosis. With regard to mammalian endpoints, category members are liquids of moderate volatility. Inhalation and skin contact therefore represent the primary route of exposure. Xylene
isomers and ethylbenzene account for >95% of the total aromatics present and are the key drivers in establishing and assessing health effects. It can therefore be assumed that streams meeting the applicability domain will behave in a similar manner and that use of read-across is valid.
For mammalian endpoints, the classification of these streams will be driven by the content of xylene isomers and ethylbenzene, which together account for >95% of the total for all category members.