Formaldehyde Exposure from Laminate Flooring: How Bad is It?
On February 18, 2016, a release from the Centers for Disease Control (CDC) announced that formaldehyde exposure from certain types of laminate flooring is more problematic than previously thought. Just how bad is it? And just how bad is formaldehyde exposure in general?
The release comes with cooperation between the CDC and the U.S. Agency for Toxic Substances and Disease Registry (ATSDR). The ATSDR part of the U.S. Department of Health and Human Services, provides information on toxic substances and provides a registry of toxins.
The new release actually corrected a mistake made in the previous calculations regarding the cancer risk. The previous report had calculated airborne formaldehyde concentration using a ceiling height that was not appropriate.
The CDC didn’t say what ceiling height they used in the initial report, but it must have been very high. The new calculations found that formaldehyde exposures were three times what the initial report calculated.
Just how bad is laminate formaldehyde exposure?
Both the initial and the new report stated clearly that laminate flooring can produce asthma and other respiratory issues. Here is their statement about respiratory issues:
“Exposure to the range of modeled levels of formaldehyde in indoor air could cause increased symptoms and other respiratory issues for people with asthma and COPD [Chronic Obstructive Pulmonary Disease]”
The phrase, “range of modeled levels” means the scientists created a sample of exposure, based on a house with laminate flooring. This is given the amount of formaldehyde that has been found to off-gas from some laminate test results. The indoor dimensions of a typical house were used to calculate the amount of formaldehyde released. This allowed the researchers to estimate whether the amount of formaldehyde in the air was enough to produce asthma, COPD and other respiratory issues.
By “range” the announcement is discussing all levels, from the lowest to the highest air levels of formaldehyde given different household dimensions and different laminates.
The CDC also discussed that formaldehyde in laminates can produce irritation in the eyes, the nose and the throat:
“Exposure to the lowest modeled levels of formaldehyde could result in eye, nose, and throat irritation for anyone”
This statement is qualified by “exposure to the lowest modeled levels.” Again, the same sampling of a typical household was used. But in this statement, the “lowest modeled levels” means that even the smallest levels of formaldehyde exposures within our household air can cause irritation in these mucosal membranes.
The next statement is the one that has created the biggest stir, though this appears a bit out of proportion given the other risks. This statement discussed the cancer-causing nature of the airborne formaldehyde released by laminate flooring:
“The estimated risk of cancer is 6-30 cases per 100,000 people. Because of the very conservative (health protective) nature of the models used in this analysis, the calculated risk is likely lower than our modeled estimate.”
The previous calculation on the cancer-causing nature of airborne formaldehyde was 2-9 cases per 100,000 people. This means the new announcement found the potential to cause cancer was three times greater than previously announced.
The announcement concluded with a simple statement:
“Our recommendations will likely remain the same –we strongly stress taking steps to reduce exposures, which should alleviate respiratory and eye, nose and throat irritation. These steps should also reduce the cancer risk.”
Is formaldehyde really that bad?
The first two parts of the announcement – about respiratory diseases and ear, nose and throat irritation – are pretty emphatic. These are based upon an accumulation of information from various studies. These include occupational studies where formaldehyde levels were extremely high, along with animal studies and large population studies. Together, the information has provided a staggering amount of evidence illustrating that formaldehyde exposure can cause issues in the lungs, sinuses and oral cavity.
For example, in 2011, researchers from the University of Alabama at Birmingham conducted a meta-analysis of studies that connected asthma in children with typical household or school exposure to airborne formaldehyde. They found seven studies on asthma in children to analyze. These studies equated to a 17 percent increased risk of asthma due to formaldehyde exposure, using a random effects model.
Mice and rat research has found that formaldehyde exposure produces skin allergic reactions along with reactivity in the airways. This reactivity – sensitivity syndrome illustrated that formaldehyde affects the mucosal membranes of the lungs, airways and skin.
These sensitivity effects were found in mice and rats to eventually produce respiratory cancers.
The CDC, together with other government agencies throughout the world have reviewed the evidence of respiratory issues and formaldehyde. Most agencies have concluded that different types of irritation issues can result, along with respiratory system cancers.
What about cancer and formaldehyde?
The statistics calculated above – of 6-30 cases per 100,000 – equate to a 0.03 percent risk assuming 30 per 100,000. This is rather low in terms of absolute risk. But this must be considered within context. The data is assuming ambient household air in a house floored with formaldehyde laminate.
But we have to remember that this is increased risk. There are many other carcinogens in our environment. This produces what we might call an accumulation of carcinogens. If we were to combine the various carcinogens in our environment, formaldehyde would increase our risk.
In early studies on formaldehyde, researchers found that mice and rats exposed to formaldehyde initially had respiratory and mucosal membrane effects. But later, many developed cancers. These were also respiratory system cancers such as lung, nose, throat and oral cancers. Many developed squamous cell carcinomas of the nasal cavity, for example.
Human research confirmed the links between formaldehyde and these types of cancers. Several occupational studies of humans have found nasopharyngeal cancers increased among workers exposed to greater levels of airborne formaldehyde. This included a study of more than 25,000 workers in plants that had higher airborne levels of formaldehyde. While a few studies found no such link, in 2012, the International Agency for Research on Cancer concluded the evidence was enough to announce:
“Formaldehyde causes cancer of the nasopharynx”
In terms of mechanisms, recent research has found that formaldehyde alters the miRNA of human respiratory mucosal cells.
In recent years, another type of cancer linked with formaldehyde exposure is leukemia. A study from the School of Medicine at the University of California at San Diego and Johns Hopkins studied formaldehyde exposure among 25,619 formaldehyde workers. They were followed from their first year at the company and followed up as many as 40 years later.
This study found that those workers with cumulative exposure to formaldehyde over the years had 3.76 times the Hodgkin leukemia. Those with peak exposures had more than five times the rates of Hodgkin leukemia.
Still, the researchers suggested the associations were “tentative” – mostly because no previous study has found this association. I would add again that they studied the histories of more than 25,000 people.
Reproductive and developmental effects of formaldehyde
Are these the only issues formaldehyde can cause?
Sorry. Wish it was. Besides the various issues related to respiratory irritation – which includes asthma, COPD (Chronic Obstructive Pulmonary Disease), allergies and other related conditions – we can add issues related to reproduction.
A 2011 study from the University of California at Berkeley conducted a meta-analysis of studies. They found that increased formaldehyde increased the risk of spontaneous abortion by 76 percent. They also found that abnormal pregnancies increased by 54 percent for formaldehyde-exposed women.
As they reviewed the animal research, the scientists found that formaldehyde produced reproductive problems, often among males that included damage to chromosomes and DNA. They also found higher levels of oxidative stress, changes in hormone and enzyme production, along with altered DNA methylation and other epigenetic effects.
Other research has linked formaldehyde to menstrual conditions among female formaldehyde workers.
Neurological effects of formaldehyde exposure
A few recent studies from Japan have found that chronic exposure to formaldehyde is linked to neurological damage in mice. The studies have linked low-dose volatile gas chemicals with olfactory bulb damage and effects upon the piriform cortex and amygdala.
Turkish researchers investigating the potential of neurological and behavioral effects of formaldehyde added some particulars:
“Of particular concern to the authors are anatomists and medical students, who can be highly exposed to formaldehyde vapor during dissection sessions. Formaldehyde is toxic over a range of doses; chances of exposure and subsequent harmful effects are increased as (room) temperature increases, because of formaldehyde’s volatility.”
Besides these effects, formaldehyde has been shown to disrupt our body’s superoxide dismutase and glutathione peroxidase activities. This means a heightened level of toxins, as these enzymes help the body remove toxins from the blood and lymphatic system.
How much airborne formaldehyde is toxic?
A 1988 EPA study found that formaldehyde levels among homes in the U.S. ranged from 0.10 parts per million to 3.68 ppm. They found the higher levels were found among manufactured homes. Today, average indoor levels have decreased. According to the US Consumer Product Safety Commission, formaldehyde is often at levels inside of 0.03 parts per million in indoor air.
Decades ago, 3 parts per million of airborne formaldehyde was considered the maximum safe level. Times have changed. According to the most recent U.S. Occupational Safety & Health Administration data safety sheet, more than 0.5 parts per million of formaldehyde is considered “actionable.” In other words, dangerous.
Yet the research illustrates that airborne formaldehyde concentrations that are as low as 0.24 parts per million can produce irritation of the respiratory tract among people.
These levels equate to airborne levels that are below 0.1 milligrams per cubic meter. These levels are considered at low risk, according to the research. But as levels become higher, problems become more likely. The asthma research mentioned above illustrated that exposures of 10 milligrams per meter-squared were linked with asthma.
Okay, so let’s compare these levels with regulated emissions from laminate flooring. Here are the EPA’s emission standards that exist today in the United States:
• Hardwood plywood has a maximum emission allowance of 0.05 parts per million.
• Particleboard has a maximum emission allowance of 0.09 ppm
• Medium-density fiberboard has a maximum emission allowance of 0.11 ppm
• Thin medium-density fiberboard has a maximum emission allowance of 0.13 ppm
This said, in testing conducted by 60 minutes in 2015, 30 of 31 cartons of laminate purchased in the U.S. had greater levels than this. Some had as much as 13 times these allowable levels.
How are laminates made?
Laminate flooring is manufactured by pressing together four layers of materials. A core layer of pressed wood is sandwiched between a bottom balancing layer fiberboard and a pattern layer. This pattern layer is basically a thin printed sheet with images that appear to be natural wood. This pattern layer is covered with a resin layer – typically made of melamine.
The glues and resins used in laminate flooring to press the wood together and glue each layer will often contain formaldehyde. Pressed wood in general is a typical source of formaldehyde as it is present in the resin that locks together the wood fibers into the final sheets of wood.
Is laminate the only source of formaldehyde?
We all wish. Formaldehyde is used as a preservative and sterilizing agent for numerous goods. These include furniture, rugs and carpets, paints, caulks, household insulation materials, fiberboard, particleboard, chipboard and plywood, various types of fabrics and even some paper products.
This means many cabinets and other wood furnishings in the house can be off-gassing formaldehyde in addition to laminates.
Smoking is also a source of formaldehyde. This comes from the chemicals used in tobacco and the paper. Gas furnaces and wood burning stoves can also increase formaldehyde levels. And car exhaust also produces formaldehyde.
Taking action on formaldehyde
These recent announcements have put the laminate flooring industry on notice. Hopefully other industries that utilize formaldehyde will be encouraged to reduce their use of this volatile product.
If you have laminate flooring, know that things have improved since the 1980s when laminates were chock full of formaldehyde. And yes, after 30-40 years of off-gassing, the formaldehyde concentrations in these floors will be much lower.
New laminates have much less formaldehyde than they used to – yes. But it is the new laminates that we should be wary of. Because their off-gassing will be greater when the laminate is new.
The same for furniture, rugs, carpets and fabrics. For this reason, open windows are a must in any household. And exposing furnishings to sunlight and heat as much as possible – regardless of their age – will speed up their outgassing. This includes formaldehyde and other volatile organic compounds.
Learn about long-term and safe cleansing:
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60 Minutes. More on tests used to investigate Lumber Liquidators. March 4, 2015.
World Floor Covering Association. How Laminate Flooring Is Made. Accessed Feb. 22, 2016
Agency for Toxic Substances & Disease Registry. Formaldehyde and Your Health. Accessed Feb. 22, 2016.