Chemical industry

FKM (Viton®) is the choice for hydrocarbon and chlorinated solvents, fuels, mineral acids, and oils at higher temperatures; it is unsuitable for ketones (acetone, MEK), esters, amines, and hot water/steam. EPDM, by contrast, resists aqueous solutions, dilute acids, alkalis, and steam (not strongly oxidising acids), but NOT mineral oils. FFKM handles almost everything, including extremely aggressive media, but is the most expensive — choose it only where neither FKM nor EPDM is enough.

EPDM swells and loses its sealing ability on contact with mineral oils, fuels, and hydrocarbons — they are chemically incompatible. For these media choose NBR (up to normal temperatures) or FKM (for higher temperatures and more aggressive fluids). Keep EPDM for water, steam, brake fluids, and water-based chemicals.

Use our chemical-resistance chart and look up the specific substance and concentration — compatibility depends on temperature and concentration too. For a mix of several media, always choose the material based on the most demanding component. When in doubt or with an unknown mixture, consult our technician free of charge.

EPDM has excellent resistance to ozone, UV, and ageing in air — which is why it is used outdoors and in ozone processes. NBR, by contrast, cracks relatively quickly under ozone and UV. When aggressive chemistry and ozone combine, choose FKM or FFKM depending on the specific medium.