It depends. It is resistant to virtually all water based products including diluted acids and alkalis, methanol, ethanol and silicone oils.
It has limited resistance to paraffin oil, vegetable oils, diesel fuels and Vaseline, which may attack the surface of EPS after long term contact.
It is not resistant to hydrocarbons, ketones, esters, paints containing thinners and solutions of synthetic adhesives.
In the case of roof insulation care should be also taken when dealing with hot bituminous asphalt to prevent melting or collapse of EPS insulation sheets.