Will It Attack Your Rubber Seals and Gaskets?
eugene-a-xylol Anyone who pumps, stores, or sprays xylol (xylene) eventually runs into the same problem: the solvent is fine, but the rubber around it fails. Hoses go soft, O-rings swell, and pump seals start to weep. Xylol is an aromatic solvent, and aromatics are hard on many rubbers, so the material of a seal matters as much as the metal of the tank.
Here is how common elastomers tend to cope with xylol:
| Rubber / elastomer | Resistance to xylol |
|---|---|
| Viton (FKM) | Excellent; the usual choice for aromatic solvents |
| PTFE | Excellent; inert but not truly elastic |
| Nitrile (Buna-N) | Poor to fair; swells and softens |
| EPDM | Poor; attacked by aromatics |
| Natural rubber | Poor; swells badly |
| Neoprene | Poor to fair; limited resistance |
| Silicone | Poor; swells and weakens |
The practical rule is short: for anything that has to hold xylol for long, seals, gaskets, pump diaphragms, hose liners, reach for Viton or PTFE and be skeptical of the rest. Nitrile, the default in many fittings, may survive a brief contact but will not last in constant service. When you buy a pump or hose for solvent duty, check that its wetted parts are rated for aromatics rather than assuming a general chemical hose will do. As always, these are tendencies, and a specific compound or grade can behave differently, so confirm with the maker’s chart for anything critical.