High temperatures cause the alcohol to evaporate, creating flammable vapors.
– The hotter, the faster it evaporates, the bigger vapor cloud you get that can ignite, says Peter Albertsson, an expert at MSB, to the radio.
Sparks can occur from static electricity.
– You don’t feel them and you don’t see them, but it’s enough to ignite a steam cloud like this, says Albertsson.
He advises keeping hand sanitizer cool and using bottles with tight lids.