With all the discussion about this issue, we think a potentially important factor may be going unnoticed. This is the role of humidity or moisture content in the formaldehyde emissions from laminate flooring and other materials.
After Hurricane Katrina, many people were moved into small trailers for temporary housing. Complaints of formaldehyde and other contamination were soon heard. Studies were done to determine the validity of the complaints.
Below is a link to one such study, of how relative humidity affected emissions from materials containing glues similar to those used in laminate flooring. Basically, a 35% increase in equilibrium relative humidity, from 50% to 85%, led to an increase in formaldehyde emissions of 1.8x to 2.6x.
So how is this information on humidity and formaldehyde relevant to Florida homes? Over the years, Indoor Environmental Technologies (IET) has seen many instances of moisture problems under laminate flooring installed on concrete slab subfloors, caused by water vapor passing through the subfloor and accumulating under the top layer of the laminate, which forms a very nearly perfect vapor barrier. Since humidity affects emission of formaldehyde by changing the moisture content of the material, we can assume very high equilibrium relative humidity in the wood components of these materials, probably often higher than the 85% in the study linked above.
This means that under common humid Florida conditions, laminate flooring may be emitting formaldehyde at a multiple of what shows up in standard laboratory tests.
Keep in mind that the real issue is not the emission rate from the laminate flooring, it’s the concentration to which occupants are exposed. This is influenced by many factors, most notably the ventilation rate of the home.
Contact IET if you have questions.
For frequently asked questions on flooring and formaldehyde concerns, please follow this link from the California Air Resources Board (CARB):