As much as I like putting a nice finish on a wood project, that first whiff of fumes from the can kind of spoils the experience for me. I suppose it’s because I don’t like getting bombarded with a witches’ brew of chemicals –chemicals that may – or may not – be safe for me to breath.
The problem is that it’s nearly impossible to finish a piece of wood without releasing some amount of toxins in the air. Whether we like it or not, the chemical properties of a finish — like the solvents, the pigments, the binders — are what make a finish what it is.
The trick then, is to choose a finish with the least amount of hazardous chemicals in the mix, but still effective in creating a durable, long-lasting surface.
So what exactly makes one finish more hazardous than another?
Actually, it’s a combination of many different things. But the top three factors that really tell the story about how safe a particular finish might be are:
1) VOC rating
2) Solvents used in the finish
3) How the finish is applied
Each of these play an important part in determining the overall toxicity of paints, stains, and clear topcoats. So it’s important to consider all three before drawing any conclusions about how safe a particular finish really is.
First let’s take a look at VOC Ratings
VOC stands for—volatile organic compounds.
Federal law requires that manufacturers include a VOC rating on the label. The rating is important because VOCs can pose certain hazards to the environment and to the person using the product. The rating is displayed in grams per liter (g/l), and tells us the relative concentration of VOCs that are present in the mix
Now when we say “Volatile” we’re talking about “VAPOR” — so a VOC rating is all about the gases that escape from a finish before it has a chance to dry.
As a general rule, the lower the VOC rating, the less potential hazard this product might pose. However, there’s a little more to the story than that.
Is a Low VOC Rating Enough? Maybe not…
I think we can all be happy that manufacturers are developing new finishes with lower VOC ratings. That’s the good news. The bad news is that we’re often lead to believe that VOC ratings give a complete picture of the potential hazards lurking in the can. Unfortunately, this isn’t always true. Sometimes understanding the true toxicity of a product goes beyond what a simple VOC rating can tell us. The VOC rating is not a complete picture of the toxicity of a finish.
That brings us to my second consideration when choosing a finish:
Taking a Close Look at the solvents found in the can.
There are a lot of different types of solvents used in finishes, but the top four–worst of the worst–solvents that you should avoid in a finish are:
1. Ethylene Glycol (solvent)
2. Benzene (solvent) carcinogen
3. Toluene (solvent) (less hazardous than benzene) flammable
4. Xylene & Naptha (solvent)
These chemicals are bad news. They’re linked to cancer, liver and kidney damage, and are even outlawed in some states. With all the new finishes that are out there today, there’s really no reason for project builders like us to buy products that contain these chemicals.
Sometimes the best way to avoid hazards in a wood finish is to simply be smarter about how you use the product. For example…
Buy Only What You Need
Keeping unused paint and finish in the shop is bad for both you and the environment. Even with our best attempts to keep a tight lid on the container, unused finishes usually end up emitting VOCs into the home indefinitely. And while some of us know better than to toss a near-empty container of finish into the trash—many don’t realize (or care) that whatever chemicals we put in the garbage can ultimately find there way into our groundwater. If you have leftovers, check with your local waste management office to find out about special pick-up days or drop-off points for getting rid of unused paint and finishes.
The best place to apply a finish is outside—in a driveway, the backyard, or a garage with the door open. This will keep the fumes away from the house, and prevent toxic chemicals from building up indoors where you and your family spend most of your time. I realize this isn’t always practical. So if you must work indoors, take a few extra precautions, like opening windows, running fans, and wearing a mask. If you’re pregnant, have allergies, or are extra sensitive to chemicals, stay out of the area for at least 48 hours.
Use Finishes that Last
The more often you have to refinish your wood project, the more often you expose yourself and the environment to whatever toxic chemicals are in the can. In some cases, this means a finish with a higher VOC rating might actually be a better choice, if it provides a longer lasting surface that does not need to be refinished. This is especially true for projects that are put under harsh conditions — like floors, tables, and outdoor projects.
Want to Learn More About Finishing Pine?
If you’d like to learn more about finishing pine, I have a complete guide available at my website, www.ezwoodshop.com. The 26-page ebook takes you step by step through the entire process — starting with how to prepare the surface properly, and then how to apply some of the more popular types of finishes — like stains, paint, and a clear topcoat.