Formaldehyde can be found in a variety of common household items including certain types of furniture, hygiene and cosmetic products, gas ovens, candles, and air fresheners. It’s also naturally present in fruits and vegetables such as bananas, apples, and carrots.
Although formaldehyde is toxic in high concentrations, it’s relatively harmless at low levels. That being said, it’s important to be aware of the presence of formaldehyde in your home so you can be sure it’s within the safe range.
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What is formaldehyde?
Formaldehyde is a colourless, pungent, flammable gas at room temperature with the chemical formula CH2O. It’s also commercially available as an aqueous solution called formalin – a product that’s commonly used to preserve biological specimens.
Formaldehyde is the simplest type of aldehyde. It has a carbon atom that is double-bonded to an oxygen atom and single-bonded to two hydrogen atoms. As we explain below, formaldehyde has many industrial applications and is often used as a precursor to various chemical products.
What is formaldehyde used for?
Whether it’s in a gas or an aqueous solution state, formaldehyde has several commercial and industrial applications. It’s primarily used in industry as a chemical precursor for other chemical products including resins like urea formaldehyde, melamine, and phenol formaldehyde. In fact, resin production makes up more than half of the total industrial use of formaldehyde.
Formaldehyde-based resins are used to manufacture particle boards and fibreboards, which is one of the main reasons why the substance is often prevalent in the home. They’re also used as finishers in the fabric industry to create crease-resistant fabrics. Meanwhile, some polymer resins are foamed to produce insulation materials.
In addition to resins, formaldehyde can act as a precursor in the manufacture of polyfunctional alcohols. These polyfunctional alcohols are then used to manufacture other products. For example, pentaerythritol is used in the production of paints and explosives.
Formaldehyde also has a variety of niche applications such as disinfectant, biocide, tissue fixative, and embalming agent.
Is formaldehyde dangerous?
Formaldehyde can be very dangerous if you’re exposed to high concentrations of it over a certain time period.
The substance is highly toxic and becomes a threat to human life at a concentration of 100 ppm, although it can still pose serious health risks at a relatively low concentration of 20 ppm or above. Typically, the acceptable limit of formaldehyde exposure over an eight-hour period is 0.75 ppm.
As a hazardous chemical, formaldehyde can irritate and even burn skin upon contact. If inhaled, it may damage the lungs and lead to a narrowing of the bronchi. This can cause fluid to accumulate in the lungs (a condition known as pulmonary oedema), which can potentially lead to pneumonia.
If high concentrations of formaldehyde are absorbed by the body via any route, there’s a risk of metabolic acidosis, organ damage, coma, or even death. There’s also evidence to suggest that long-term or chronic exposure to the substance can increase your chances of developing certain types of cancer.
Where is formaldehyde found in the home?
Formaldehyde can be found in trace amounts in food and other items in the home. It’s largely present in treated woods that contain resin, as well as some fabrics. Brand new wood materials and fabrics usually have the highest levels of the chemical, although the concentration tends to diminish over time.
Below are a few examples of common household products that contain formaldehyde.
Pressed wood
Pressed wood materials are composite wood layers that are pressed together using resins such as urea formaldehyde resin, melamine resin, and phenol formaldehyde resin. Cheap flatpack furniture is often made using these types of resins.
Hygiene products
Some hygiene products, such as lotions, shower gel, baby wash, and shampoo may contain formaldehyde. Traces of formaldehyde may also be present in cosmetic products like nail polish.
Gas ovens
Gas ovens use liquified petroleum gas (LPG), which may contain one or more of the following types of gases:
- 100% propane
- 60% propane and 40% butane
- 35% propane and 65% butane
The combustion of these gases produces trace amounts of formaldehyde, which can then accumulate in the oven over time.
Living room furniture
Living room furniture like sofas, wooden sideboards, and coffee tables are usually manufactured from various materials, some of which are treated with formaldehyde-based resins. Brand new furniture often contains relatively high concentrations of formaldehyde, but since the chemical is volatile these levels will usually diminish after the plastic covers are removed.
Air fresheners & candles
Air fresheners and scented candles may contain limonene, a chemical that can react with ozone (a type of gas molecule) to produce formaldehyde. However, in reality, there is insufficient ozone in our homes to produce significant amounts of formaldehyde from its reaction with limonene.
You can read more about some of the other common chemicals you might find in your home here.
Can formaldehyde increase in the home?
The concentration levels of formaldehyde in our homes can fluctuate. Nonetheless, new furniture and other household products treated with formaldehyde-based resins can increase the concentration. Other sources that may contribute to a rise in formaldehyde levels in the home include tobacco smoke and LPG gas ovens.
To help reduce these levels, ensure your home is well-ventilated, air new furniture, ban smoking indoors, and wash permanent press clothing before use. If you’re still concerned, speak to a professional for advice.
Can formaldehyde cause allergies?
At certain concentrations above the safe level, formaldehyde may trigger allergic reactions in some people. Allergic reactions may vary from one person to another, although contact dermatitis is often a common symptom in those who are allergic or sensitive to formaldehyde. This is one of the reasons why it’s a good idea to wash permanent press clothing before use.
Summary
Formaldehyde is a colourless organic compound that’s present in a variety of household products including pressed wood furniture, cosmetic and hygiene products, gas ovens, and some candles and air fresheners.
The substance is primarily used in the manufacture of resins. Formaldehyde is highly toxic at high levels, although most homes don’t contain enough formaldehyde to produce any ill effects. You can help to keep formaldehyde levels within the safe range by ensuring your home is well-ventilated, airing new furniture, and banning smoking indoors.
