The Scoville Heat Unit (SHU) is a measurement of the pungency (spiciness or ‘heat’) of chilli peppers and other spicy foods.  It is based on the concentration of capsaicinoids, among which capsaicin is the predominant component. 

WARNING:  Please note that you should take every care when tending chilli plants or preparing chilli pods/seeds.  Wear gloves at all times when handling and DO NOT rub unprotected areas, ie. eyes, nose and mouth.