Linseed oil, obtained from flax seeds, is a common go-to for woodworking projects. It’s great for showcasing the natural beauty of wood and giving it a nice shield against water damage and decay, especially during home renovations or when treating wooden surfaces. But, when it comes to using linseed oil on items like cutting boards or other kitchen tools, is linseed oil food safe? That’s a significant question for both DIYers and seasoned woodworkers.
The discussion on whether linseed oil is safe for contact with food centers around its different types – raw, boiled, and polymerized. Each one has its own set of properties and reactions when applied to wood. The big concern is around the use of these oils on wooden kitchenware such as bowls, cutting boards, and butcher’s blocks, that may come in direct contact with our food.
In this article, I’ll break down the specifics of each type of linseed oil (raw vs boiled linseed oil vs polymerized linseed oil), showing how they interact with wood and their level of food safety. All the important information is captured in a comparison table for an easy overview.
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Is Linseed Oil Food Safe?
Yes, linseed oil is food-safe, but the type matters. Raw and polymerized linseed oil are safe options; however, the long drying and curing time of raw linseed oil might be impractical for certain projects like oiling cutting boards and butcher’s blocks.
Boiled linseed oil dries faster due to added chemicals, but these additives make it unsafe for food contact. It’s important to choose the right type of linseed oil based on your project requirements and food safety considerations.
How is Linseed Oil Made?
Linseed oil is made from the small seeds of the flax plant, utilizing either pressure application or solvent extraction methods. The pressure technique is more conventional and organic, pressing the seeds to extract the oil, while solvent extraction uses chemicals to achieve a more efficient extraction.
Both methods serve the common goal of retrieving the precious oil from flax seeds, yet the method selected can impact the purity and the overall quality of the linseed oil produced. Pressing is typically preferred when aiming for a more natural end product.
What is Linseed Oil Used For in Woodworking?
Linseed oil is versatile and has a wide range of uses across different fields. It serves as a nutritional supplement in food, an additive for paints in the art domain, and a protective wood finish in woodworking. The oil not only protects but also provides a nice finished look, enhancing the color and bringing out the texture of the wood in a pleasing way.
When it comes to woodworking, here are some advantages of using linseed oil:
- It provides a degree of water-resistance to wood.
- A thin layer forms on the wood, offering scratch protection.
- The color of the wood looks richer and the texture stands out more.
- It’s a good choice for kitchen items as it’s safe to use once it has fully dried and cured.
- The oil hardens over time, creating a durable finish that helps the wood last longer.
However, there are some downsides to consider:
- The drying and curing process can take days or even weeks.
- Once oiled, wooden surfaces will need reoiling now and again.
- Some might find the scent unpleasant as the oil ages.
- Unlike some other finishes, linseed oil doesn’t provide UV protection.
- Not all types of linseed oil are safe for food, so you’ll need to pick the right one, especially for kitchen projects.
Variations of Linseed Oil
Linseed oil has three main variations—raw, boiled, and polymerized. Each type is crafted differently, leading to unique features suited for various uses, especially in woodworking. Let’s go through each variation to understand their characteristics regarding dry time, purity, toxicity, and practical use.
Raw Linseed Oil
Raw linseed oil, also known as pure linseed oil, is as natural as it gets, extracted straight from flax seeds with no further processing or additives. However, it dries very slowly, often taking several days to weeks to fully cure, which might not be ideal for projects that need to wrap up quickly. Its major advantage is its purity; there are no toxic additives, making it safe to use, particularly in items like children’s furniture, cutting boards, or kitchen utensils.
Boiled Linseed Oil
Despite its name, boiled linseed oil is heated and treated with chemicals to speed up the drying time. By adding metallic dryers or solvents to the raw linseed oil, the drying process is sped up. The resulting boiled oil dries faster when applied to wood. This comes in handy for projects on a tight timeline, though the added chemicals mean it’s not as pure, and it could be toxic. It’s a go-to choice for many woodworking projects, but not the best for items that will come in contact with food.
Polymerized Linseed Oil
Polymerized linseed oil is heated in a controlled environment, which helps it dry quicker than raw linseed oil, but not as fast as boiled linseed oil. It offers a middle ground in terms of purity – safer than boiled but less pure than raw. It’s a suitable choice for a range of woodworking projects, offering a good balance between drying time and less toxic composition.
NOTE: Polymerization is a way to change linseed oil by heating it in a controlled setting, often between 220 to 300 degrees Celsius. When heated, the oil molecules connect with each other, forming long chains. This process changes the linseed oil from a liquid to a solid or semi-solid form, which is great for woodworking projects. It makes a hard, protective layer on the wood, making it look good and last longer. This change also speeds up the drying time of the linseed oil.
Raw vs Boiled Linseed Oil - Comparison Table
The table below compares the raw, boiled, and polymerized linseed oil based on purity, toxicity, drying time, safety for food contact, and typical types of usage.
|Raw Linseed Oil||Boiled Linseed Oil||Polymerized Linseed Oil|
|Purity||Pure, no additives||Chemical additives||Heated, no chemicals|
|Drying Time||Slow (days to weeks)||Fast (hours to a day)||Moderate (1-2 days)|
|Safe for Food||Yes, once fully dried||No||Yes, once fully dried|
|Type of Use||Furniture finishing, Cutting Boards and Butchers Blocks, Kitchen Utensils, Wooden Toys||Outdoor Furniture, Wood Sealing, Fast-drying Projects||Indoor Furniture, Fine Woodworking, Artistic Applications|
Can You Use Linseed Oil on a Cutting Board?
Yes, linseed oil can be used on cutting boards and butcher blocks, but not all variations are suitable. For a safe application on your cutting board, stick to raw or polymerized linseed oil (food-grade linseed oil), ensuring it’s fully dried and cured before use.
However, linseed oil might not be your best bet for protecting your cutting board. Here’s why:
- Linseed oil does repel water and adds a nice shine once applied. But being an organic oil, it can turn rancid over time, which could leave an unpleasant smell or taste on the board. Although, some high-quality cold-pressed linseed oil has a light, mild scent that’s almost unnoticeable, but scent appreciation can vary from person to person.
- Typically, film finishes tend to crack and peel over time. They don’t hold up well and can be affected by frequent washing, which is inevitable with cutting boards and butcher blocks. This would mean reapplying the oil more often to maintain the finish.
- Using linseed oil as a wood finish doesn’t provide a clear finish but rather gives the wood a yellowish tint. So, if you’re looking to preserve or slightly darken the natural colors of your cutting board, you might want to consider using a different oil.
- The drying and curing time of raw linseed oil can range from two weeks to a few weeks, making it a less practical choice for use on cutting boards.
NOTE: Rancidification is when the fats and oils in substances like linseed oil break down into smaller parts because they come into contact with air, light, or moisture. This breakdown can lead to bad smells and tastes, which can make the oil less desirable or not suitable for certain uses.
Other Food Safe Cutting Board Oils
Raw linseed oil is safe to use and can be applied on cutting boards or butcher blocks. However, it’s not the top choice for these items and there are better alternatives available. Let’s explore these options more closely to understand why they might be better suited.
Mineral oil has been one of my go-to finishes for cutting boards as it doesn’t oxidize and has no smell or taste to affect your food. It creates a water-resistant barrier on the wood, keeping it safe from water damage. Unlike other oils, the board soaks up mineral oil within 2 to 4 hours, making the whole process quick and easy.
This oil comes from petroleum and is non-toxic, making it safe for use on food surfaces. It’s important to pick food-grade mineral oil or white mineral oil to ensure it’s safe for kitchen use. Regularly applying this oil prevents your cutting board from drying out or cracking, considerably extending its lifespan.
While linseed oil takes time to dry, I’ve leaned towards mineral oil as it requires no drying time. It seeps into the wood, protecting the fibers without leaving any residue on the surface.
Beeswax is a natural choice for maintaining your cutting board, offering a way to hydrate and shine it, while also providing a waterproof barrier. You can find it in products like Boos Board Cream or make your own mixture with mineral oil. Applying a beeswax blend not only prevents the board from cracking but also gives it a smooth finish and a longer life.
TIP: Mixing mineral oil with beeswax creates a fantastic treatment for chopping boards, wooden trays, and other wooden items. This mixture offers longer-lasting protection compared to using just mineral oil. The good news is, that you can easily make this mixture at home, saving you both time and money for future woodworking projects.
Frequently Asked Questions
What is the Difference Between Linseed Oil and Flaxseed Oil?
Linseed oil and flaxseed oil are essentially the same oil derived from the seeds of the same plant. The difference mainly lies in the terminology where “linseed oil” is often used to refer to the product used for art and wood finishing, while “flaxseed oil” is the term commonly used in the U.S. for food products.
Is Pure Linseed Oil Food Safe?
Yes, as long as it’s 100% pure with no additives, pure linseed oil is safe for food contact, making it a suitable option for treating cutting boards and other food preparation surfaces.
Does Linseed Oil Go Rancid?
Yes, linseed oil can go rancid over time due to its organic nature and exposure to air and moisture which can lead to unpleasant odors and flavors.
Is Polymerized Linseed Oil Food Safe?
Yes, polymerized linseed oil is safe for food contact surfaces since it’s heated without chemicals to achieve a level of curing.