Tree nut oils generally come in two kinds: refined and unrefined.
1. Refined Oil: When a tree nut oil is refined, the chances of the proteins of that food being in the oil are low. While pure refined oils (various tree nuts and also peanut) exist, it is always safer to avoid nut oil completely since there is no definitive way for a consumer to know how much protein is in that oil.
2. Unrefined Oil: Nut oils that are cold-pressed,” “unprocessed,” “expelled,” “extruded” are unsafe for nut allergic individuals. All of these are much more likely to contain nut and/or peanut proteins.
3. Where Nut Oils are Found: It’s easy enough to avoid nut oils on your own shopping list, but also be mindful of them when eating out. In restaurants, be sure to ask waiters specifically about salad dressings and sauces; chefs sometimes use nut oils to enhance flavors.
Nut oils are also found in some cosmetics and body-care products. When shopping, pay specific attention to lip balms, lipsticks and lip glosses since those are coming in direct contact with your mouth.
Sources include: Dr. Antony Ham Pong, allergist
Related Reading: Is Peanut Oil Safe for Peanut Allergy?