Health - Indoor Air Quality
The issue of indoor air quality (IAQ) gained attention in the 1980s when people learned that many building materials emit harmful chemicals into the air that make people sick.
VOCs
Volatile organic compounds (VOCs) are chemicals that can become a gas at room temperature, some of which have short and long term health risks. One of the most common and dangerous VOCs is formaldehyde, which is used as an adhesive, bonding agent and solvent. Sources of VOCs are primarily industrial processes that emit 58%, motor vehicles that emit 37%, and consumer solvents that emit 5%.
Formaldehyde
Formaldehyde is an important chemical used widely by many industries
to manufacture adhesives that are used in various building materials
including engineered wood products, carpeting, paints and wood finishes.
Building materials that contain high levels of formaldehyde are
a major concern because they can off-gas into building interiors
and affect interior air quality long after the products are installed.
Formaldehyde is a colorless, strong-smelling gas that can cause watery eyes, burning in the eyes and throat, nausea, fatigue, and difficulty breathing in some humans exposed at levels above 0.1 parts per million.
Some people are very sensitive to formaldehyde, while others have no reaction to the same level of exposure. High concentrations may trigger attacks in people with asthma. It has also been shown to cause cancer in animals and is now believed to cause cancer in humans.
Formaldehyde Limits
According to the California Air Resources Board:
“In 1992, formaldehyde was formally listed by the Air Resources Board as a Toxic Air Contaminant in California with no safe level of exposure. Health risks from total daily average formaldehyde exposures in California from all sources are estimated to range from 86 to 231 excess cancer cases per million for adults, and from 23 to 63 excess cancer cases per million for children” (http://www.arb.ca.gov/toxics/compwood/factsheet.pdf).
Here are the limits to formaldehyde emissions required by a number of agencies:
World Health Organization:
Below 0.10 ppm
European E1 Standard: Below 0.10 ppm
OSHA Hazard Communication Standard: Hazard warning labels on any
manufactured product that may emit 0.10 ppm or greater
GreenGuard® Environmental Institute Certification: Below 0.05 ppm
State of California: Below 0.05 ppm
Sources of Formaldehyde
In
residential and commercial construction, the most significant sources
of formaldehyde are likely to be pressed wood products that are
made using adhesives that contain urea-formaldehyde (UF) resins.
Engineered wood flooring is one example of a pressed wood product
that often uses adhesives containing urea-formaldehyde. Other pressed
wood products that are made for indoor use includes particleboard,
hardwood plywood, medium density fiberboard (MDF), and high-density
fiberboard (HDF). MDF and HDF contain a higher resin-to-wood ratio
than any other UF pressed wood products, and are generally recognized
as being the highest formaldehyde-emitting wood products. MDF and
HDF are often used as substrates for laminate and some engineered
wood flooring.
Other engineered wood products, such as softwood plywood and oriented
strand board (OSB) are produced for use in exterior construction
and contain the dark-colored phenol-formaldehyde (PF) resin. Although
formaldehyde gas is emitted from both types of resins, pressed woods
that contain PF resin generally emit formaldehyde at considerably
lower rates than those containing UF resin.
Eco Friendly Flooring Using Zero Formaldehyde Adhesives
To avoid formaldehyde
off-gassing, high quality eco friendly engineered flooring is made
with a non-formaldehyde glue called EPI. Once EPI adhesives have
cured, they are inert (no off-gassing whatsoever). EPI glues are
also superior in performance as they are stronger and more flexible
than the urea-formaldehyde glues traditionally used in the wood
flooring industry.
The 'I' in EPI stands for isocyanate. Precautions need to be taken
with isocyanate in its liquid form, as it can have harmful effects
at high concentrations. Responsible factories that use EPI adhesives
make sure that protective measures are taken for the employees that
work around the substance.
Isocyanate is also found in some installation
adhesives that are used on construction jobsites to glue flooring
down to the sub-floor.
Since
most flooring installers generally do not carry adequate protection
and usually work in somewhat confined spaces, isocyanate should
be avoided in installation glues. Some ‘low-VOC’ or ‘zero-VOC’ installation
adhesives that are currently on the market contain isocyanate, xylene,
and other hazardous chemicals. Although a product may have a low
VOC content, that does not make it safe. EcoTimber’s HealthyBond
installation adhesive is ultra-low-VOC and contains no hazardous
chemicals or solvents.
EcoTimber products that do not use EPI adhesives use PVA adhesives
(known as ‘white glues’) that contain no formaldehyde and do not
require any protection for those working around them. Modern formulations
of PVA adhesives have made them as strong and water-resistant as
urea-formaldehyde glues.
If it weren't for the small amounts of formaldehyde that are naturally
emitted by wood, EcoTimber's flooring products would emit no formaldehyde
whatsoever -- the glues and finishes are not contributing to the
overall formaldehyde emissions. All EcoTimber flooring products
easily meet both the European E1 formaldehyde standard and the new
California Air Resources Board regulations, including the most stringent
CARB standard that won't go into effect until 2012.