Formaldehyde is one of those chemicals we’ve all heard of—when we’re not considering its environmental health impacts, most of us probably think of it as embalming fluid, and indeed it is its primary ingredient. Yet most people have little idea of what it actually is, how it affects human health, and just how common it is. Its presence in many common products made from wood is a large part of why Thinktanks office pods are constructed of recycled aluminum instead.
Formaldehyde is a type of Volatile Organic Compound (VOC) that, in addition to being common in nature, is found in many consumer products. At room temperature, formaldehyde is a colorless, flammable gas with a strong odor. Small amounts of it are produced naturally by all life on Earth—plants, bacteria, animals, and of course humans. Because of this, we are always exposed to small levels of the chemical, and at low levels it is easily and harmlessly broken down by our bodies and exhaled or excreted through urine. As with many potentially toxic substances, though, the dose makes the poison.
The good news is that naturally-occurring levels of formaldehyde aren’t problematic for public health. The Occupational Safety and Health Administration (OSHA) has established a “permissible exposure limit” of 0.75 parts per million and a “short-term exposure limit” of 2 ppm, though concentrations as low as 0.1 ppm can cause problems. Most people can smell formaldehyde at a concentration of between 0.25 ppm and 1 ppm.
There are many ways that formaldehyde exposure levels can be increased in our environment to levels well above OSHA’s 2 ppm limit. Indoor air, in particular, can have significantly higher levels than our bodies can handle. Just a few of the common sources include:
- Cigarette smoke
- Resins found in composite and pressed wood products like plywood, particle board, and medium-density fiberboard (MDF)
- Permanent press fabrics
- Urea formaldehyde foam insulation
- Some paper products
- Consumer products like cosmetics, dishwashing detergent, and fabric softeners
- Un-vented gas stoves
Health effects of formaldehyde exposure
Being as common as it is, it’s only natural to wonder about the effects of increased levels of formaldehyde on environmental health, and especially public health. Fortunately, it is one of the best-studied of environmental chemicals in the United States. Here are a few of the problems we know of:
When ingested intentionally, as in suicide attempts, formaldehyde can corrode mucous membranes and “has been associated with extensive congestion, hemorrhaging, and necrosis of the gastrointestinal mucosa.”
A more important concern is the long-term exposure to elevated formaldehyde levels in the environment. Although there is no definitive link between formaldehyde exposure and gastrointestinal problems in humans, male rats exposed to 82 milligrams of formaldehyde per kilogram of body weight per day (mg/kg/day) for up to two years did experience a number of gastrointestinal issues, including “papillomatous hyperplasia with hyperkeratosis, chronic atrophic gastritis, focal ulceration in the forestomach, and hyperplasia in the glandular stomach.” Similar effects show up in female rats at an exposure of 109 mg/kg/day.
Body weight effects
Studies in rats again have shown a connection between formaldehyde exposure and a reduction in body weight. Rats exposed to 300 mg/kg/day of formaldehyde weighed as much as 45% less than controls exposed to a more “normal” 50 mg/kg/day.
Though there have not been conclusive studies showing this connection in humans, these animal studies are still cause for concern.
There are many reported cases of neurological problems from ingesting formaldehyde, including coma, seizure, and loss of consciousness. These are typically the result of intentionally consuming formaldehyde in apparent suicide attempts.
Looking at accidental exposure, there is some evidence that infants exposed to elevated levels of formaldehyde in the air are more likely to develop neurological diseases as adults.
Asthma and other respiratory problems
Some studies have shown a link between high levels of formaldehyde in the air of newly-painted homes, and higher frequency of asthma. Young children exposed to formaldehyde in the home also have been shown to have a significantly increased risk of asthma. Anyone exposed to levels above about 1 ppm is likely to experience wheezing and coughing, whether related to asthma or not.
Many people are allergic to formaldehyde, and even those without allergies can experience burning sensations in the eyes, nose, and throat. When exposed over longer periods of time, allergic contact dermatitis can develop.
This is quite likely the biggest concern, as several United States and international health agencies have found it to potentially cause cancer in humans. It was first listed in the National Toxicology Program’s Second Annual Report on Carcinogens in 1981.
“Formaldehyde is known to be a human carcinogen,” according to the U.S. Department of Health and Human Services. The Environmental Protection Agency (EPA) and the Agency for Toxic Substances & Disease Registry (ATSDR) both classify it as a “probable human carcinogen,” while the International Agency for Research on Cancer (IARC) says that it is “carcinogenic to humans.” The National Toxicology Program (NTP) says that formaldehyde is “reasonably anticipated to be a human carcinogen.” While no single study can be seen as conclusive, it’s obvious that there’s a very strong consensus that long-term exposure to formaldehyde can cause cancer in humans.
This is clearly a worry, but it’s not cause for outright panic. Most recent studies show that it is “significant and prolonged exposures to inhaled formaldehyde” that are linked to an increased risk of cancer. Normal environmental exposure has not been shown to raise cancer risk. Still, people exposed to unusually high levels on a regular basis have good reason to be concerned.
The most frequent types of cancer linked to formaldehyde exposure are nasopharyngeal cancer (cancer of the nasopharynx—the uppermost part of the throat) and cancers of the nasal sinuses. There may also be a connection between exposure to formaldehyde and leukemia; myeloid leukemia in particular. Studies on the myeloid leukemia/formaldehyde connection are conflicting, but there is little dispute as to the chemical’s carcinogenicity.
There are a number of industries and occupations where formaldehyde is used regularly. Because it is used to preserve biological specimens, those who work in medical labs or mortuaries are likely to deal with it on a regular basis. Biology students and professors might also be exposed frequently.
Of course, it’s not just those working in laboratories who are at risk. According to the National Institute for Occupational Safety and Health (NIOSH), some of the industries where high exposure levels are common include:
- Plastic, resin, and foam insulation manufacture
- The funeral industry
Exposure in the office
It may seem that a typical American office worker has little cause for distress. While the sources of formaldehyde exposure aren’t quite as obvious, office workers still should be aware of the formaldehyde in their workplace. Indoor air pollution is a problem in offices, too, and unlike industries that regularly work with toxic materials, a typical office doesn’t usually provide the ventilation to handle these pollutants.
In an office environment, your most likely source of formaldehyde is wood furniture and building materials. Wood itself is a source of formaldehyde, and although natural, unfinished wood is unlikely to cause problems on its own, the glues, resins, paints, and finishes used on products made from wood frequently release high levels into the surrounding air.
Off-gassing of formaldehyde and other VOCs is highest in newly-produced pressed wood products. Over time, its release will decrease. This is worth considering whenever the time comes to replace your office furniture. That brand-new desk is quite likely to contain formaldehyde in much higher concentrations than your current one, and could be releasing fairly high levels of VOCs for a good amount of time.
Limiting office exposure
The California Air Resources Board (CARB) has found that “inhalation of formaldehyde emitted from composite wood products containing urea-formaldehyde resins” is one of our most significant indoor air problems. CARB is working with the EPA to develop stronger national standards for wood composites, and in 2016 the EPA published new standards designed to minimize emissions of formaldehyde from wood products. The new standards have not yet been fully implemented, so minimizing negative health effects now starts with minimizing the use of wood products—pressed-wood products in particular—in your office.
Of course, it would be impractical—not to mention costly—to get rid of all your wood furniture. It may not be necessary either, since the off-gassing decreases over time. It does take a while for that formaldehyde to be completely eliminated—it's being released into your indoor air for six to ten years, according to the Healthy House Institute. Still, your older furniture should be the last consideration. Instead of trashing what you already have, put more consideration into any new purchases.
When looking at new furniture, there is a wide variety of materials it could be made from. To keep formaldehyde levels low, your best options are made from non-wood building materials.
Metals are a great choice. They are durable and relatively lightweight and contain none of the resins or glues used in products made from wood. Aluminum is a particularly good selection, as it weighs less than most other metals and is one of the most recycled materials available, making it eco-friendly even beyond the confines of your office. In fact, recycled aluminum is the material we use in all of our privacy pods.
Plastics can also be a good choice for some items, though they should be chosen cautiously. They are less durable than most metals, but are generally less expensive and lighter-weight. Most plastics are also recyclable, and many products are made with recycled plastic—something to look for when you’re shopping. However, some types of plastic such as melamine do contain formaldehyde themselves.
Another option is solid wood. Unlike products of compressed wood like particle board or MDF, solid lumber does not contain resins that are known to be problematic to human health. Remember, though, that wood itself does release small amounts of formaldehyde into the air. On its own it is generally not a problem, but consider what else might be adding to the formaldehyde levels.
If you are considering solid wood furniture, keep in mind that even solid wood is usually held together with formaldehyde-containing glues, and formaldehyde is also often found in the paint or varnish that’s used.
Indoor air can contain a great deal of toxic materials that can end up in our lungs, and the environmental health effects aren’t always known. Yet knowing the risks of excessive formaldehyde in the air we breathe, and particularly its potential as a human carcinogen, minimizing our exposure is in all of our best interests. While federal government agencies like the EPA strive to help, it’s up to all of us to protect the health of ourselves and those around us.