Question

Is bamboo flooring with aluminum oxide finish considered a green choice?

Asked by Liz Cohen

We are considering purchasing a new loft apartment in a multi-use neighborhood and complex. The building provides bamboo flooring with aluminum oxide? I'm concerned about offgassing from the finish. Please comment.

Answer

Mary Cordaro

Answered by Mary Cordaro

Southern California Areas, CA

Mary Cordaro, Inc.

January 28, 2010

Liz, you're right to be concerned about possible indoor air quality issues from wood flooring finishes. The good news is there are now more decent alternatives to standard construction and interior design materials. You just need to do some homework.  

There are three things to consider here:

  1. First, your concerns regarding the aluminum oxide finish itself.
  2. The second concern is what will happen when you eventually need to refinish the floor.
  3. The third concern deals with what's underneath that pretty bamboo surface.

Let's take each one separately. First -- the finish itself.

Aluminum Oxide Finishes

Aluminum oxide finishes can be fast-curing and healthy from a chemical outgassing standpoint, depending on a few variables. Unlike some water-based polyurethane finishes, which often contain chemicals called glycols that may “outgas” for several months (and may not be easily detected by odors), UV-cured aluminum oxide finishes, which are modified urethane finishes, are often well-tolerated even by chemically sensitive individuals. This is particularly true if the finish is baked-on and UV-cured, which is usually the case with prefinished wood floors.
 
But here’s where things get more complicated, unfortunately. Besides low chemical toxicity, there are some additional factors to consider regarding an aluminum oxide finish. First, from a healthy house standpoint, very little if anything is known about possible health effects from the aluminum content in aluminum oxide floor finishes.
 
In the past few years, there has been a growing, heightened awareness of the potential toxicity from nano-sized heavy metals in products that touch the skin. Although this concern has been directed primarily at personal products, it is worth considering for any product that touches the skin. One MD I know of, whose patients include chemically sensitive people, has been strongly advising against aluminum oxide finishes, due to the possibility of aluminum oxide absorption through the skin on bare feet.
 
Prompted by these concerns, a client with an autistic child requested that I look into one particular flooring product, called Bellawood, a brand that is well tolerated by many chemically sensitive people. Bellawood is a solid hardwood flooring product, prefinished with UV-cured, baked-on aluminum oxide urethane.  Bellawood is coated multiple times and comes with a 50-year warranty on the finish. I spoke with a technical expert who works for the industrial finish manufacturer that makes the Bellawood finish. He reported to me that the aluminum oxide particles in the finish are much larger than nano-sized. In fact, we both agreed that theoretically, the aluminum oxide particles are probably much too large to penetrate bare skin.
 
I have not researched other aluminum oxide finishes in terms of the particle size, but it’s possible, given the similar characteristics of aluminum oxide finishes in general, that this may be true for other brands as well. However, as far as I know, there really is no real conclusive data on this issue, regarding possible toxicity from skin contact. So even if you have an aluminum oxide finish, if you want to be on the extra safe side, just wear socks and slippers indoors.

What About Refinishing?

Besides the concern about aluminum absorption, the other factor to consider is refinishing. Sanding down an aluminum oxide finish will release aluminum oxide particles. With the Bellawood finish, given the multiple coatings and the extensive warranty, it’s not as likely that refinishing will be necessary. However, this may not be true for all brands of aluminum oxide prefinished bamboo flooring. In fact, if you do a Google search on bamboo flooring with aluminum oxide finishes, you will find reports by some disgruntled homeowners complaining about poor durability, including scratching and even flaking. 

From product to product, quality will vary of course, so find out which product was installed in the apartment loft you are considering, then go online to check out how it’s holding up for others. However, even If it’s holding up well overall, you might still give some consideration to eventual sanding and refinishing down the line.

To prevent inhalation of aluminum oxide, it would be prudent to budget for airtight protection of your HVAC system, airtight isolation of rooms that are not to be refinished during sanding, and special ventilation, called negative pressurization, to keep the dust from migrating into the rest of the house. 

After refinishing, I also recommend completing a serious deep-cleaning on all horizontal and vertical surfaces, including ceilings. True deep-cleaning should be performed by a highly experienced, qualified mold remediation company, that follows the SB520 standards, and so has all the right equipment and skills (for more information, go to http://iaqa.org/).

In addition, during application and curing, you will need to include, depending on your geographical location and the time of year, portable ventilation, dehumidification and heat (since you can’t use your HVAC system) so the finish goes on and cures out properly. All those extras can be an expensive proposition, but until more is known about inhaling aluminum oxide, I would recommend those precautions.

Bamboo Flooring and Glues

Bamboo flooring is more than the finish and the wood surface you can actually see. These types of floors are most likely laminated, not solid bamboo, and held together by glues. So make sure that the glues are formaldehyde-free if possible. Then expect to ventilate well anyway, for several months, particularly if you are chemically sensitive or have small children in the home.  

Even though odor may not necessarily be apparent, formaldehyde-free glues still contain chemicals called isocyanates which, unlike formaldehyde, dissipate much faster and easier. However, isocyanate chemicals are still somewhat toxic, particularly for sensitive individuals, so fresh air exchange for the first 6 months to a year is very important. If the glues are not completely formaldehyde-free, check with the manufacturer to make sure the levels tested low, then ventilate with fresh air for the first 6 months to a year.  

 

For more information:

Read GreenHomeGuide's "Make Floor Refinishing Greener and Safer" for floor refinishing tips.

HealthyBuilding.net has extensive coverage of formaldehyde levels and health.

Tagged In: bamboo flooring, home air quality, floor refinishing

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