Using a power strip is green: Back when a new desktop computer was as...

You might know it best as that bookshelf that arrived in 109 pieces, with "some assembly required." This dense, heavy, inexpensive substitute for wood or plywood consists of wood chips or sawdust that is compressed along with a synthetic resin or other binder. Because urea formaldehyde (UF) is the resin most commonly used, particleboard is a major source of formaldehyde offgassing in homes; products made with low- or zero-formaldehyde resins are available and a safer alternative. For some purposes-such as cabinetry-formaldehyde-free medium density fiberboard (MDF) or wheatboard can be used in its place.

Mold isn't just a patch of blue to indicate your bread's gone bad. There are molds that grow on...