In efforts to save energy, new homes are very well sealed and well insulated. The result is a lower energy bill, but inadequate fresh air infiltration. Well insulated homes can accumulate formaldehyde and become unhealthful environments.
Composite wood (such as plywood, particleboard, and MDF) are well known for emitting formaldehyde. Green building programs such as LEED encourage avoiding composite wood in home interiors.
Fiberglas insulation may also emit enough formaldehyde to exceed healthy home recommendations. The culprit is not the Fiberglas itself, but the resin used to bind the fibers into batts. Those Fiberglas batts are installed in the walls of many homes.
Modeling of chamber test data indicates formaldehyde emitted from wall insulation can exceed the California Chronic Reference Exposure Level of 7 ppb formaldehyde. Three different brands of Fiberglas insulation emitted enough formaldehyde to raise indoor formaldehyde concentrations to 10 ppb, 11 ppb, and 14 ppb formaldehyde.
The chamber test studies only addressed formaldehyde from wall insulation. There are numerous other formaldehyde sources in the home. Composite wood cabinets, closed organizers, flooring, and trim can all emit formaldehyde into the home.
Once a home is occupied, composite wood furniture can be additional sources of formaldehyde. Industrial hygienists find that furniture is the primary formaldehyde source in some homes. In some cases, bedroom furniture emitted so much formaldehyde that occupants become ill.
Health conscious home owners can select wall insulation that is not bonded with a formaldehyde resin. A number of insulation products do not contain any added formaldehyde.
Ventilation is the single most import feature of a healthy home. Bringing fresh air into the home dilutes airborne chemicals and removes formaldehyde from the home. Formaldehyde concentrations are highest in the heat of the day, so ventilation is most important in late afternoon and evening.
Ventilating a home is as easy as opening windows. Bay area afternoon breezes are a pleasant and inexpensive way to bring fresh air into the home.