New style safety relief valves have changeable O-ring. Standard comes with a Viton® O-ring, but you may request an EPDM O-ring if preferred. EPDM holds up to certain solvents and alcohol based chemicals better.
Look at SFTY-1 original style safety relief if you have trouble with low maximum pressures. We have found the original style has a stronger spring and can hold better pressure. Note that the original reliefs are only available in EPDM sealing material, no Viton®.