ODOR INVESTIGATION

Odor complaints are some of the more difficult investigations to carry out. Different people have varying awareness and sensitivity to odors. Odor perception is very subjective. Often clients take action on their own to address odor concerns by ventilating a space or installing deodorizers that mask the odors. When that happens, Certified Inspectors investigators do not have a chance to “experience” the claimed odor under worst case conditions; so we may have to return. (Additional site visits entail additional costs.)

Common Odor Complaints may Involve

1. Moldy/musty odors – Those are associated with active mold growth under damp conditions. Different molds produce different odors ranging from sharp odors often associated with Penicillium colonies or heavy odors associated with Chaetomium a white mold that grows on damp wood (paneling or structural wood in crawl spaces). Since molds are biological organisms as are mammals, like humans, they also give off vapors/gases as they actively digest the organic matter in their surroundings. HENCE: that “moldy/musty odor” is the indication that there is biological activity nearby in some damp pocket.
2. Rodent odors – The unique odor of mouse urine is often encountered from infestations since mice dribble their urine as they walk, thus marking a wider area than might be expected from just a nest. They love to tunnel into fiberglass insulation in walls and ceilings.
3. Chemical odors – These odors often come from containers of solvents, thinners, etc. after pin-hole leaks develop as a results of damp conditions that lead to rust deterioration of containers. They also can come from interior leaks associated with fuel oil (tanks, fittings, lines, etc.) or puff-backs from improper combustion in oil furnaces.
4. Headaches – These occur if there are elevated levels of combustion gases such as carbon monoxide (CO) from poorly vented combustion equipment or leaking exhaust flues.
   

Odor Detection or Testing

We have found over the years that the human nose is pretty good at detecting and identifying odors, even if subjective. Sometimes clients have concerns about whether a perceived odor is associated with toxic compounds. In that case Certified Inspectors may try to sample the vapors in an area and send to a specialized lab for identification. Using specialized sorbet tubes to absorb the vapors out of the air or special stainless steel canisters for whole air grab samples, it is often the case that chemical vapors that can be smelled by humans are not readily detected by even the most advanced laboratory equipment that can reach detection limits of tenths of a part per billion (ppb); so that sampling and analysis process can be frustrating with frequent “non detects” reported.

For combustion gases, Certified Inspectors can use hand-held instruments that have adequate sensitivity to be helpful in investigations. While there are hand-held instruments for organic vapors and “air toxics,” those instruments have much lower sensitivity than is available from grab sampling and advanced analysis – around the range of tenths of a part per million (ppm) – hence seldom very useful.