The partial closure of the University of Manchester campus on March 4th is a stark reminder of the risks posed by hazardous areas and potentially explosive materials in densely populated areas.

In a city where the memory of the damage caused by explosives is still fresh in many minds almost 20 years on from the 1996 IRA attack, authorities are understandably cautious about any possible explosion.

On March 4th, a perfectly innocent research project at the Paper Science Building on Sackville Street went awry, when the individual in charge of the experiment discovered some acetone peroxide had crystallised.

This makes it highly volatile and susceptible to explode if it experiences a sudden shock or change in its environmental conditions.

As a consequence, a large area around the former UMIST campus was closed – including Sackville Street, Whitworth Street, and the slip road connecting to the Mancunian Way.

It was several hours – and a controlled explosion by the bomb squad – before the hazardous area was deemed safe enough to reopen.

The incident is a reminder of how even innocent chemicals, if they react in the right quantities, can create volatile compounds – and why any such experiments in built-up areas should be carried out using the appropriate hazardous area equipment and other suitable safeguards.