Final answer:
Arc flash is a dangerous explosion caused by a fault or short circuit in an electrical system. It can cause severe burns and even fatalities.
Step-by-step explanation:
The 'A' in 'BESAFE' stands for arc flash. An arc flash is a sudden release of electrical energy that can result in a dangerous explosion. It occurs when there is a fault or short circuit in an electrical system, causing an electric arc to form.
Arc flashes can reach extremely high temperatures, can cause severe burns, and can even be fatal. They pose a significant risk to anyone working on or near electrical systems, which is why proper safety measures, such as using appropriate protective equipment and following safe work practices, are crucial.