Reactive drywall, more commonly known as Chinese drywall, was imported from China between 2001 and 2009 due to an American shortage of material. It contained extraneous materials such as sulfur, strontium, and iron. In warmer and more humid climates, this drywall emitted various sulfur gasses that caused copper and other metal surfaces to become black and powdery.

Odors emanate from a variety of sources: the off-gassing of incomplete combustion, decomposing organic matter, building materials, water intrusion, etc. There have been many articles written regarding various odors and the products or equipment to resolve these odors.