It is about 180,000 Scoville units on the Scoville scale. The scale measures the spicy heat or piquance of a chili pepper. Compare this to the the 2,500-5,000 units of the popular Tabasco sauce.
The original Dave's Insanity Sauce came out in 1995 after the hot sauce interests began growing in 1989 with the Fiery Foods and Barbeque Show. When it was released it was one of the very first to use capsaicin extract, which allows it to be hotter than the hottest habanero-pepper sauces.