Most of the problems with VOCs are connected to new construction and remodels. Besides using low-emitting materials, ventilation should be adjusted during the course of a remodel, and following a remodel or new construction. During the remodel, areas being worked on must be isolated so air does not flow from them to other areas of the building. This is done by shutting off returns and exhausting air directly from the construction areas to the outside of the building.  In new buildings or following a remodel, the amount of fresh air supplied to the building should be increased to compensate for the higher than normal levels of VOC emissions. In fact, one authority recommends supplying 100% outside air for the first 6 months.

One VOC that should be considered by itself is formaldehyde. Individuals can become sensitized to it and thereafter experience adverse reactions (mainly respiratory effects) at even extremely low levels of exposure.There are other VOCs for which this same type of effect can occur (for example, MDI, which is produced when polyurethane foam cures).  Formaldehyde is given off at quite high rates by what is called "medium density particle board," which is frequently used in mobile home (and some other home) sub-flooring, and in cabinetry and the like. Since its toxic properties have become well known, manufacturers now make the material so it emits at much lower levels. Nevertheless, this material is of concern and individuals sensitive to formaldehyde can suffer serious health effects from living in a home in which a great deal of it is present.

In the last few years there has been a lot of controversy about carpets as a cause of IAQ problems. This began with an incident in the EPA headquarters building in Washington, D.C., where a number of employees became ill following some renovations, including installation of new carpeting.  Following this incident, a laboratory put some mice in a chamber with a piece of carpet. The mice died.

VOCs give off high levels of vapors, so one is likely to inhale significant amounts of them if they are present. Many VOCs are toxic. VOCs are also extremely common. Any time you apply a material which is intended to dry out, there are almost always VOCs present. Paint, white out, paint stripper, and almost any kind of cleaner fall into this category. Plastics are manufactured with VOCs, as are many other materials.

VOCs are a broad class of chemicals which contain carbon atoms and which are either gas or liquid. Liquids tend to give off high levels of vapor at normal temperatures. Gasoline and common solvents are typical examples.