The release and ignition of which chemical were linked to the Flixborough disaster in June 1974?

• A. Cyclohexane
• B. Ethanol
• C. Propane
• D. Toluene

Answer: (A)

A large release of a flammable liquid that forms a vapor cloud which can ignite is a major industrial hazard, and the Flixborough disaster is a classic example of this. In June 1974 a temporary bypass pipe around a reactor failed, releasing a vast amount of cyclohexane. The cyclohexane vapor mixed with air and found an ignition source, triggering a catastrophic explosion that destroyed the plant and caused many deaths. This event highlights how quickly a seemingly simple piping modification can create an enormous fire and explosion risk if a flammable liquid is involved.

The substance tied to this incident is cyclohexane, which matches the plant’s feedstock and the reported release. Ethanol, propane, and toluene were not the chemicals involved in this disaster, so they don’t fit the historical linkage.