Along with lighters, lithium batteries and liquid peroxide, probably the most unusual item on the International Air Transport Association's Dangerous Goods Register is the innocuous-seeming coconut.
Coconut meat has a high oil content. It's regarded as highly combustible and therefore constitutes a fire hazard. It's forbidden either as hand luggage or in checked-in luggage.
It's actually copra, the dried coconut meat, that's the problem, however the ban applies to coconuts generally, apart from retail packaged coconut products which are permitted.
In India, where flyers often carry coconuts, either as food or as a sacred item that has been ritually blessed by a Hindu priest, it seems the reason for the ban is misunderstood.
Security screening staff in India will sometimes require that a coconut be broken in two before it can be carried on board.
This does not take account of the fact that it is the copra itself that is the hazard, not the liquid inside.
There has never been a case recorded in which a spontaneous combustion of copra has caused a fire on an aircraft, but you can't be too careful.