Over the weekend, more than 500 students and members of staff had to be evacuated from a university library in Melbourne, Australia, because of a suspected gas leak. After a "comprehensive search" of the building, the local fire brigade department concluded there was no gas leak. Instead, the source of the trouble was a much less sinister miscreant – a single piece of rotting fruit.

The foul-smelling durian fruit is native to Southeast Asia, where it is often eaten raw or added to local cuisine as a flavoring ingredient. It can also be used in traditional Asian medicine, either as an aphrodisiac or as a treatment for fever. It is about the same size as a coconut and looks a bit like a curled up hedgehog. Underneath its spiky green and brown exterior, there is a sweet and creamy yellow flesh. 

The "king of fruits" is the marmite of the fruit world – you either love it or hate it. The scent is so pungent that the Singapore Mass Transit has banned durians on their railway lines and, in a particularly scathing review, the food writer Richard Sterling describes the odor as "turpentine and onions, garnished with a gym sock. It can be smelled from yards away.” (Mmm, nice. Not.)

This unique stench is the product of 50 individual discrete compounds, including four that had been totally unknown to science until a 2012 study analyzing the smell of durian fruit was published in the Journal of Agriculture and Food Chemistry. The researchers found that no one compound was responsible for its smell but rather combine to create the distinctive scent. Taken apart, some compounds were described as fruity while others were described as skunky, metallic, rubbery, or burnt. Some were described as smelling like onions, others garlic, cheese, or honey.

Australian firefighters believe the especially pungent smell of this particular piece of rotting fruit spread through the RMIT library through the air conditioning system. An investigation into the incident took place because of the potentially dangerous chemicals stored in the building but the library has since been re-opened now that they know there is no risk to staff and students' health. Though library staff might want to consider banning durians from now on.

Its powerful, sulphuric stench isn't the only uncommon trait of the durian fruit. Asian folklore states eating durians while drunk can kill you and there may be a hint of truth in this claim. In 2009, a study found that eating durians can inhibit an enzyme called aldehyde dehydrogenase (ALDH), which is responsible for helping the liver break down alcohol.

If you want to know what it tastes like, check out this brilliant video below by Cut (warning: there's swearing. Quite a lot). 

[H/T: Associated Press, Scientific American]