Interior Finishing and Trim
When shopping for interior finishes people usually concentrate on style. You should also keep personal health in mind and look for materials that don't contain toxic chemicals or off-gas in your home. All natural materials are best for the inside of your house. MDF (medium density fiberboard) is a commonly used interior wall finish that contains formaldehyde which off-gases into the air. Luckily, there are healthier alternatives available.
MDF Alternatives
Higgins Hardwoods (707) 584-0136
http://www.higginshardwoods.com/
Home Depot - All locations
http://www.homedepot.com/
Moldings (Recycled)
Home Depot - All locations
http://www.homedepot.com/
Plaster (Natural and Renewable Materials)
Tile (Recycled, Natural, and Renewable Materials)