Steve these are rated for oil and water.
From McMaster
Spring-Loaded PTFE Shaft Seals
Graphite-Reinforced PTFE—Excellent wear and extrusion resistance in liquids, steam, and other severe conditions. PV limit (pressure × velocity) is 15,000 psi-fpm for air; 300,000 psi-fpm for water; and 520,000 psi-fpm for oil. Color is black.