Indoor Air Quality Program
The Department of State Health Services (DSHS) has received numerous calls in the last few years from people reporting a black soot-like residue accumulating on surfaces in their homes. The residue is commonly observed on white or light-colored plastic objects and appliances – even inside of refrigerators, dishwashers and computer disk drives! It also may stain carpets and furniture. This problem seems to be most common in newer homes and apartments. Unfortunately, there is no one answer as to what causes this, but it has often been related to burning candles or some other combustion source such as a fireplace. These common sources of soot problems should be ruled out as possible causes before looking further.