The Scoville scale is a measurement of pungency of chili peppers and other substances, recorded in Scoville heat units (SHU). It is based on the concentration of capsaicinoids, among which capsaicin is the predominant component.
Pepper stand at Central Market in Houston, Texas, showing its peppers ranked on the Scoville scale
The ghost pepper of Northeast India is considered to be a "very hot" pepper, at about 1 million SHU.
The Naga Morich, with around 1 million SHU, is primarily found in Bangladesh.
The Red Savina pepper, a hot chili.
Pungency refers to the taste of food commonly referred to as spiciness, hotness or heat, found in foods such as chili peppers. Highly pungent tastes may be experienced as unpleasant. The term piquancy is sometimes applied to foods with a lower degree of pungency that are "agreeably stimulating to the palate". Examples of piquant food include mustard and curry. The primary substances responsible for pungent taste are capsaicin, piperine and allyl isothiocyanate.
A display of hot peppers and the Scoville scale at a supermarket in Houston, Texas
A display of spices in Guadeloupe: some pungent, some not