Oh dear... The Scoville Scale

A scale developed by Wilbur Scoville in 1912, to measure the heat level in chillies. It was first a subjective taste test, but since, it has been refined by the use of HPLC, the unit is named in honour of its inventor. The original Scoville test asked a panel of tasters to state when an increasingly dilute solution of the pepper no longer burned the mouth. Roughly one part per million of chilli 'heat' rates as 1.5 Scoville units. The hottest pepper recorded was a Habenero. Pure Capsaicin measures 16,000,000 Scoville units.

Valuable information from here