These batteries are safe during normal use, but present a fire risk when over-charged, short-circuited, submerged in water or damaged. They are a main cause of waste fires, and can be extremely dangerous when thrown away with general rubbish, or mixed with other recyclable materials like card, metals and plastics.

Lithium-ion batteries are extremely sensitive to high temperatures and inherently flammable.  These batteries can cause fires that quickly spread and are difficult to extinguish, causing widespread damage.