I have an MSDS for CaOCL that says "A fire or explosion may result if calcium hypochlorite is mixed with other chemicals, including other pool chlorinating compounds, cyanuric acid, or pool treatment chemicals, contaminated with acids or brought into contact with any easily combustible materials such as oil, kerosene,gasoline, paint products and any other organic materials." In an emergency response class once I saw a movie where someone poured oil or diesel fuel onto some CaOCL and within a few minutes it ignited into a large fire.