Do foul odors diffused in the air render clothes or water impure, and is prayer valid with clothes if soap remains on them?

Foul odors do not necessarily originate from something impure (najis). Even if they result from impurity, such as the steam from pork, they do not defile clothes or the body. Similarly, smoke and steam transformed from an impurity are pure. The persistence of soap residue on clothes does not cause harm, even if it is derived from impurities, because detergents transform into other substances. If soap contains a small percentage of alcohol whose effect is not apparent, it does not matter. Some scholars even consider intoxicants (khamr (definition)) to be pure.