Is Linseed Oil Food Safe?

Linseed oil and food safety has gotten complicated with all the conflicting information flying around. As someone who finishes cutting boards, salad bowls, and butcher blocks on a regular basis, I learned everything there is to know about which oils are safe for food contact and which ones absolutely are not. Today, I will share it all with you.

I get this question constantly. A buddy asks me to make a cutting board, and then right before I hand it over he goes, “Wait, that oil isn’t toxic, right?” Fair question. The short answer is that some linseed oil is perfectly food safe, and some will make you sick. The difference matters a lot.

What Linseed Oil Actually Is

Linseed oil comes from flax seeds — same plant, different name. The seeds are loaded with omega-3 fatty acids, which is why you see flaxseed oil in the health food aisle at the grocery store. The cold-pressed version is basically a nutritional supplement. People put it in smoothies and drizzle it on salads.

But here’s where it gets tricky for us woodworkers. The linseed oil you find at the hardware store is a completely different animal than the bottle at Whole Foods. And mixing them up could be a real problem.

The Three Types You’ll Run Into

Probably should have led with this section, honestly. There are three kinds of linseed oil and only one of them belongs anywhere near food.

• Raw Linseed Oil: This is the industrial stuff. It’s used for wood finishing, painting, and other shop applications. It’s not refined for consumption and may contain impurities. I keep a can of this in my shop for finishing exterior projects. Would I use it on a cutting board? Absolutely not.
• Boiled Linseed Oil (BLO): Despite the name, it’s not actually boiled. Manufacturers add metallic driers — heavy metals like cobalt, manganese, sometimes lead — to make it dry faster. This stuff is straight-up toxic. I use it on tool handles and outdoor furniture, but it should never touch anything that contacts food. Ever.
• Cold-Pressed / Food-Grade Linseed Oil: This is the good stuff. Extracted without heat or chemicals, sold as a dietary supplement. It’s rich in omega-3s, completely safe to eat, and works beautifully on cutting boards and wooden kitchen utensils. This is the only linseed oil I use for food-contact projects.

Why the Food-Grade Stuff Is Actually Good for You

Cold-pressed linseed oil is packed with alpha-linolenic acid, which is an omega-3 fatty acid your body can’t make on its own. It’s genuinely healthy stuff — supports heart health, fights inflammation, and there’s research suggesting it’s good for brain function too. I take a tablespoon of it most mornings just for the health benefits, separate from any woodworking. My doctor actually recommended it.

What to Watch Out For

Even food-grade linseed oil has some quirks. It goes rancid fast if you don’t store it right. Keep it in the fridge or at least in a cool, dark cabinet. Once it oxidizes, it develops off flavors and can actually produce compounds that aren’t great for you. I buy small bottles and use them up within a month or two.

If you’ve never had it before, start with a small amount. Some people get digestive upset the first time. My wife had some stomach issues when she first tried it on a salad — nothing serious, but worth knowing about.

Can You Cook with It?

Not really. The smoke point is super low — around 225 degrees Fahrenheit. Hit it with any real heat and it breaks down, smokes, and loses all its nutritional value. I tried sauteing vegetables in it once. Tasted terrible and set off the smoke alarm.

Where it shines is as a finishing oil. Drizzle it over a salad, mix it into a dressing, add it to a smoothie. That’s what makes food-grade linseed oil endearing to us woodworkers who also care about health — it pulls double duty as both a wood finish and a nutritional supplement.

Better Options for Actual Cooking

If you need an oil you can heat, look elsewhere. Olive oil is the classic choice. Avocado oil handles high temperatures like a champ. Canola works in a pinch. Each has its own nutritional profile, but they all handle heat way better than linseed oil does.

For finishing wooden kitchen items specifically, I actually prefer a blend. I’ll mix food-grade linseed oil with beeswax for cutting boards. The oil soaks in and the wax seals the surface. Reapply every few months and your boards will last decades. The key takeaway here is simple — if it’s going near food, make sure the label says food-grade or cold-pressed. Keep the hardware store linseed oil in the shop where it belongs, and the food-grade stuff in the kitchen. Get that right and you’ve got nothing to worry about.