(NC) Whether it's a DIY project or one you hire a pro for, a home upgrade can add beauty and comfort to your living spaces. But before you start, know that some furniture and building materials made from composite wood may be a source of formaldehyde.

Formaldehyde is a colourless gas commonly found in indoor air. It can come from tobacco smoke, wood smoke and cooking. It also comes from composite wood, manufactured by combining wood fibres and adhesives to make cabinets, countertops, flooring, mouldings and furniture.

Exposure to the substance over a longer period is linked to breathing problems and increased allergic sensitivity, especially in children. At high levels, it has also been linked to cancer of the nasal passageways.

In 2010, California developed regulations to reduce formaldehyde coming from composite wood products. The U.S. then expanded on the California regulations to create a national regulation.

In 2016, the Canadian Standards Association (CSA) developed a voluntary standard on formaldehyde emissions for composite wood products manufactured in Canada. Its emission limits are harmonized with the California regulations.

Health Canada is developing regulations that will also target composite wood products. These new regulations should come into force in 2019. Until that happens, you can limit your potential exposure with these tips:

Understand what you're buying. Does it contain a composite wood product? If it does, is there a label on it that states it complies with the California Air Resources Board (CARB) or the CSA standard? Look for labels that have statements like California 93120 Phase 2 Compliant for Formaldehyde, Certified to CAN/CSA-O160, Complies with CAN/CSA-O160, and Product in compliance with TSCA Title VI. If you're not sure, don't be afraid to ask the vendor.

Keep emissions from composite wood products low. Buy items—particularly with the CARB or CSA standard—that are low-emitting or have a plastic laminate or coating on all sides, or seal these items yourself at home instead.

Limit exposure from household and building products. If available, choose no or low-formaldehyde formulations. Ask retailers or manufacturers for details.

Ensure plenty of ventilation. This is essential when you do any renovations, particularly for painting or varnishing projects and when installing any flooring using glues or adhesives.