It is named after Wilbur Scoville, who developed the Scoville Organoleptic Test in 1912. As originally devised, a solution of the pepper extract is diluted in sugar water until the 'heat' is no longer detectable to a panel of (usually five) tasters; the degree of dilution gives its measure on the Scoville scale. Thus a sweet pepper, containing no capsaicin at all, has a Scoville rating of zero, meaning no heat detectable even undiluted. Conversely, the hottest chiles, such as habaneros, have a rating of 300,000 or more, indicating that their extract has to be diluted 300,000-fold before the capsaicin present is undetectable. 15 Scoville units is equivalent to one part capsaicin per million. Thus the highest concentration of pure 100% capsaicin corresponds to 15,000,000 Scoville units. The greatest weakness of the Scoville Organoleptic Test is its imprecision, because it relies on human subjectivity. Later analytical developments such as high performance liquid chromatography (HPLC) (also known as the "Gillett Method") have now enabled the Scoville rating to be determined by direct measurement of capsaicin rather than sensory methods.

15,000,000-16,000,000
(Sources vary) Pure capsaicindihydrocapsaicin
Blair Lazar's "16 Million Reserve" product, said to be pure capsaicin

9,100,000 Nordihydrocapsaicin
8,600,000 Homodihydrocapsaicin and homocapsaicin
7,100,000 "The Source" hot sauce
5,300,000 Police grade Pepper spray
2,000,000 Common pepper spray or Pepper Bomb
350,000 - 580,000 Red Savina habanero
100,000 - 350,000 Habanero chile
100,000 - 325,000 Scotch bonnet
100,000 - 225,000 African birdseye (aka "African Devil", "Piri-Piri")
100,000 - 200,000 Jamaican hot pepper
100,000 - 125,000 Carolina cayenne pepper
95,000 - 110,000 Bahamian pepper
85,000 - 115,000 Tabiche pepper
50,000 - 100,000 Chiltepin pepper
50,000 - 100,000 Rocoto
40,000 - 58,000 Pequin pepper
40,000 - 50,000 Super chile pepper
40,000 - 50,000 Santaka pepper
30,000 - 50,000 Cayenne pepper
30,000 - 50,000 Tabasco pepper
15,000 - 30,000 de Arbol pepper
12,000 - 30,000 Manzano pepper, Ají
5,000 - 23,000 Serrano pepper
5,000 - 10,000 Hot wax pepper
5,000 - 10,000 Chipotle
2,500 - 8,000 Jalapeño
2,500 - 8,000 Santaka pepper
2,500 - 5,000 Guajilla pepper
2,500 Tabasco Sauce
1,500 - 2,500 Rocotilla pepper
1,000 - 2,000 Pasilla pepper
1,000 - 2,000 Ancho pepper
1,000 - 2,000 Poblano pepper
700 - 1,000 Coronado pepper
500 - 2,500 Anaheim pepper
500 - 1,000 New Mexico pepper
500 - 700 Santa Fe Grande pepper
100 - 500 Pepperoncini pepper
100 - 500 Pimento

0 Bell pepper

Pepper Spray and Pepper Spray is an inflammatory, not an irritant like Mace, causing immediate closing of the eyes and coughing. The length of the effects depend on the strength of the spray but the average full effect lasts around thirty to forty-five minutes, with mitigated effects lasting for hours.

Though there is no way of completely neutralising pepper spray, its effect can be minimised or stopped. As veteran chili-eaters know, capsicum is not soluble in water, and even large volumes of it will have little to no effect. It is, however, soluble in fats and oils, and detergents can be used to wash it off. Victims should be encouraged to blink vigorously in order to encourage tearing, which will help flush the irritant from the eyes. Some of the oil can be washed off the face using a degreasing, non-oily soap such as a mild dish detergent, and a fan will provide some relief. Some "triple-action" pepper sprays also contain "tear gas" (CS gas), which can be neutralised with sodium metabisulfite (Campden tablets, used in homebrewing; though it, too, is fat soluble and could be washed off to a degree with milk), or a UV "blanketing" dye (little can be done against this, but its effects are not nearly as dramatic).