Q: Our basement had some flooding — just enough to get the carpet wet. The cleaning company said it is better just to replace the carpet than try to clean and dry it. Is that true? — Todd , Ohio
A: In many cases it would be better to replace the carpeting rather than try to clean it and dry it. In cases where the amount of wetting is small and one acts quickly enough (within 48 hours), one can clean and save carpet. If the carpet is relatively new (less than 10 years old), it is likely to be made of all synthetic material, which cannot serve as a food source for mold.
If mold does grow on such carpeting (and it is not unusual), it is because of the organic matter that has accumulated in it. If one uses deep extraction cleaning one can save a carpet even if it is already fuzzy. I know of a couple of such cases in school and other buildings where carpeting was successfully remediated and thus saved.
When carpet is cleaned after a flood, many remediators and cleaners apply a biocide as a final cleaning procedure. These usually work very well and post-cleaning airborne spore counts are very low.
On two different occasions occupants reported hoarseness, chest tightness after the flooding and remediation. These symptoms are not typical of mold. In one case (not a school) I measured significant concentrations of acrolein, a potent mucous membrane irritant. Some common biocides work by producing formaldehyde as a decomposition product. Some contain 50 percent glutaraldehyde, a very potent mucous membrane and pulmonary irritant.
The use of biocides for post-flooding remediation is problematic. It virtually eliminates the potential for mold growth and human exposure. However, some biocides may pose exposure risks of their own. In most cases it is not easy to tell whether a particular biocide will pose a human exposure concern or not.
