How do I check whether silicone grease is suitable for my O-ring?

By the Atkinson Oil Co. product team (IGNIS Overseas Ltd, Isleworth, UK). Claims reviewed by IGNIS Product & Compliance on 14 Nov 2026. Last updated: 14 November 2026.

Short answer. Check what the O-ring is made of, what the equipment maker says and what the seal touches. Atkinson Silicone Grease is labelled for rubber, plastic and compatible metal components, including O-rings, seals, taps, valves and electrical connectors. Do not use it on silicone-rubber O-rings or on oxygen or breathing-gas equipment.

Key facts

Check 1: the O-ring material.

• Silicone grease is widely used on common O-ring rubbers, but check the O-ring or equipment maker's compatibility guidance before you use it.
• Silicone rubber O-rings: do not use silicone grease; it can swell them.
• If you don't know the material, ask the equipment maker.

Check 2: what the seal touches.

• Drinking-water fittings may need a grease approved for that use. Use the grease your fitting maker or regulator specifies.
• Never use this grease on oxygen, enriched-air or breathing-gas equipment.

Check 3: the maker's instruction. If the manual names a grease, use that one.

How to apply

1. Remove the O-ring if you can, and wipe it and the groove clean.
2. Make sure both are dry.
3. Apply a thin, even film to the O-ring — enough to make it glisten, not to fill the groove.
4. Refit, then check for leaks before normal use.

Silicone or red rubber? Red Rubber Grease is vegetable-based and labelled for rubber seals, O-rings, bushes and brake and clutch components. See When should I choose red rubber grease rather than silicone grease?.

Caution: avoid contact with eyes; do not ingest; wash hands after use; keep out of reach of children. Store in a cool, dry place.

Product link: Silicone Grease · Also see: Plumber & O-Ring Silicone Grease.

Sources

Printed product label; Your equipment maker's manual