Is Water Based Polyurethane Food Safe When Dry?

Is Water Based Polyurethane Food Safe When Dry

Don’t you hate it when you have a question that gets opposing answers?  Simple questions that require only a yes or no answer, and yet there seems to be a “but” that creeps in?  Of course, if this question could be answered with a simple yes or no, we’d have nothing further to write about.

Seriously, though, all products that will come in contact with your food need to be food-safe.  This includes finishes on countertop surfaces, kitchen and dining room tables, and even the plates you will eat your meals on.

Additionally, since water is an integral part of the kitchen and cooking, countertops and cutting boards need a sealant to protect woods from getting wet.  As we all know, water is wood’s enemy, leading to rot.

Among the choices for wood sealers, generally, are shellac, polyurethane (both oil-based and water-based), polycrylic, oil finishes like tung, mineral, and linseed, and even edible oils like olive and walnut.  The former, shellac, polyurethane, and polycrylic, are referred to as film finishes in that they form a coating or film on the wood surface.  In contrast, the latter oil-based finishes penetrate and soak into the wood.

Brand names in polyurethane include both Minwax and Varathane:

Minwax Polyurethane

Minwax Water Based Clear Semi-Gloss Polyurethane Water Based 1 Gl

This clear coat film finish is well known and often used in finishing woods.  It is basically a plastic applied to wood surfaces as a liquid that, in time, dries as a solid plastic sheet.  It does not sink into woods as an oil finish will; instead, it sits on the surface and provides a waterproof barrier to protect the wood.  Again, remember that water is the enemy of wood.

It is non-carcinogenic and is not absorbed by the skin.  However, if ingested, for instance, it can be harmful.  If swallowed, it can irritate the mouth, throat, stomach, and intestinal tract; if inhaled, it can irritate the nose, throat, and lungs. 

Notwithstanding this, FDA regulations consider clear wood finishes that dry to a hard sheet to be food-safe.  As with all such products, it must be allowed sufficient time for a fully dried and cured finish before using.

While it dries and cures to a hard plastic sheet, these risks should be noted, as a sharp knife and constant cutting and chopping can mar the finish as well as kick up bits of it.

Minwax Polycrylic

This, too, is a protective clear-finish top coat for wood in a water-based formula that is easily applied and dries quickly.  As does polyurethane, polycrylic forms a solid seal on wood surfaces and protects against temperature, moisture, and sunlight.  (UV rays are harmful to wood)

As between polyurethane and polycrylic, an oil-based polyurethane will give a slightly amber tone to wood over time, while polycrylic will leave a non-yellowing and clear, preserving the natural color of the woods beneath.

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Polycrylic dries faster but takes longer to cure and is not as water-resistant as polyurethane.  However, it is easy to work with and does not carry as strong a smell as polyurethane products.  Polyurethane provides a harder surface among the clear coat finishes.

Varathane

Varathane is a brand name of polyurethane products.  Varathane Crystal Clear Polyurethane will provide a clear film coat on wood surfaces that is excellent in protecting your project from scratches and stains.  It works well on indoor projects like furniture, cabinets, and window and door trim, whether stained, painted, or bare.

Rust-Oleum 200261H Water-Based Ultimate Polyurethane, 8 Fl Oz (Pack of 1), Satin Finish
  • Protects indoor wood surfaces such as furniture, windows, cabinets, trim and more
  • Water based formula dries fast and cleans up with soap and water
  • Dries to the touch in 30 minutes with coverage up to 31.25 sq. ft., recoat after 2 hours
  • Durable formula provides outstanding stain and scratch resistance with excellent clarity

Both Minwax and Varathane offer a variety of wood finish products.  While many consider Varathane to be more easily applied and have a faster drying time, Minwax is the less expensive option while still providing an effective finish.

Is Polyurethane Safe For Kitchen Tables?

Many woodworking experts suggest that a wipe-on oil-based polyurethane is a good DIY choice for your kitchen table.  It has the appearance of a more professional oil-rub finish, is easy to apply, and provides good surface protection. 

Those same experts also believe that all finishes are food-safe once they are fully dried and cured.

Polyurethane products are the toughest finishes for your kitchen table.  They protect against spills (likely to happen in families with children),  can take a reasonable amount of heat, and their finish will last for years.  We don’t recommend putting a pan right out of the oven on them – use a trivet or pad. 

We recommend at least 2 coats, but 3 coats are better.  A water-based polyurethane might raise the grain of the wood, and if this happens, a light sanding and another coat will help you give it a smooth surface, so think 4 coats in these instances.  Go the extra distance for a long-lasting finish and better protection.

Is It Safe To Use Polyurethane on Cutting Boards?

We’ve pointed out the risks of polyurethane if ingested in any way.  And, with sharp knives or cleavers, there is also the risk of surface damage over time.  While polyurethane is a good choice for countertops (so long as you won’t be cutting anything on them), it is not as good a choice for cutting boards.

Instead, we recommend the use of wood oils as the best food-safe wood finish for cutting boards, including food-grade oils, as previously mentioned.

Is It Safe To Use Polyurethane on Cutting Boards

In fact, there are wood oil products available that are specifically for cutting boards.  This is the safest way to finish your cutting board – Cutting Board Oil, Food Grade Mineral Oil, and such.  These are considered the safest food safe finishes for wood:

Even beeswax is considered a food-safe finish.

We’ve written of water-safe and food-safe finishes in the past, specifically Waterlox and Watco Danish Oil.  Each is an excellent choice for cutting boards, kitchen counters, wooden bowls (salad, fruit, for instance) and plates, and other wood surfaces in your kitchen.  You’ll find that earlier article here.

As we said at the outset, it’s not necessarily a yes or no answer to the question in the title of this article.  Yes, it might be safe with proper use, and the degree of protection afforded the wood surfaces is high. 

And now, here’s the “but”:  there are options that are clearly and inarguably more food-safe.  They are the old-fashioned finish choices, the ones that have been used in woodworking for centuries – oil finishes.  You make the choice – the newer polyurethane finishes or the oil finishes.  Each is or can be safe, but one is always safe.

Last update on 2022-09-25 / Affiliate links / Images from Amazon Product Advertising API