Particle board is manufactured by mixing together sawdust, wood chips, and scraps with a powerful adhesive. The mixture is formed into blocks and baked for a long time at high temperatures and pressures. The block hardens into a sheet that can be used for building shelving or furniture. This is similar to the method used to manufacture oriented strand board and plywood. All of these construction materials are made by gluing together pieces of wood to increase their strength and durability.
There are two major types of glue used for this process. Urea-formaldehyde glue is cheaper but less water resistant than phenol-formaldehyde glue. Both types of glue contain formaldehyde, a toxic gas. Prolonged exposure to high concentrations of formaldehyde presents a health hazard. Susceptible individuals may experience watery eyes, irritated mucus glands, nausea, and asthma symptoms. After Hurricane Katrina hit New Orleans in 2005, the Federal Emergency Management Agency provided many of the victims with trailers for temporary housing. FEMA later received criticism and negative publicity after it was discovered that many of the trailers contained unsafe levels of formaldehyde. People living in the trailers became ill and sued the government for damages. If you understand the scientific principles behind particle board outgassing, you can protect your family from a similar fate.
Understanding Particle Board Outgassing
The formaldehyde used to bind wood chips into the particle board will break down and aerosolize over time. This phenomenon has been studied extensively, and the half-life of formaldehyde calculated. The greatest amount of particle board outgassing occurs during the first year after the piece is manufactured. After the first or second year, the rate at which formaldehyde seeps out of the piece drops off considerably. However, the piece can continue emitting small amounts of gas for up to 10 years. Wood products emit more formaldehyde at higher temperatures and humidity. The emission rate is not nearly as important as the concentration of gasses in living areas. The lumber industry began self-regulating formaldehyde content in its products in 1981. This resulted in major reductions in the volumes of gas emitted. However, formaldehyde is still used in board production and outgassing still occurs, albeit at lower levels.
Managing Particle Board Outgassing
It is impossible to avoid building with formaldehyde entirely. Even if you never buy particle board furniture, the frame of your home still probably contains plywood or OSB. However, you can manage your building’s indoor air quality (IAQ) to keep your family healthy. New construction is increasingly air-tight to improve energy efficiency. When weather permits, open the windows and turn on a fan. Circulate air through the building to exhaust any built-up gases. Be sensible about the amount of formaldehyde you release into the building. When choosing particle board furniture, select older used pieces. These will have already released the majority of their gas. If you buy a brand new piece, take it out of the box and spread it out in a garage or on a porch for several days. Since the rate of formaldehyde emission decreases over time, this will allow the worst of it to escape before you bring the furniture inside.