stench

Stench refers to a strong, unpleasant odor that elicits aversion rather than pleasure. In common usage the term signals a notably disagreeable smell, and it is often used interchangeably with stink. In scientific contexts the broader term odor covers all smells, while stench marks a particularly repugnant subset.

Stench commonly arises from biological decay, waste, and chemical reactions. Typical sources include rotten or spoiled food, sewage, manure, and decomposing flesh, as well as industrial emissions containing sulfur- or nitrogen-containing compounds. Notable odorants include hydrogen sulfide (rotten-egg scent), ammonia, methyl mercaptan, trimethylamine, indole, and skatole.

Perception of stench varies by person and context. Genetic differences influence sensitivity to specific compounds; repeated exposure can lead to adaptation or odor fatigue. Odor strength is quantified with methods such as dynamic olfactometry, yielding odor concentration in odor units (OU) per cubic meter. Regulators may set limits or nuisance thresholds expressed in OU/m3.

Mitigation focuses on source control, containment, and treatment. Techniques include ventilation improvements, biofilters, scrubbers, and activated carbon filtration. In addition, maintaining cleanliness and proper waste management reduces emissions that cause stench. Culturally, the word stench conveys strong negative judgments about smells and environments.