Fog cannons, DNA spray - they sound like something out of a James Bond movie.

But the security measures, along with panic alarms and time safes for cash and cigarettes, were among options announced by Police Minister Paula Bennett yesterday as part of a $1.8 million initiative to curb the alarming spate of violent robberies plaguing dairies around the country.

Fog cannons fill rooms with a dense fog made of glycol and water forced through a heated element at the pressing of an emergency button.

It's said to be harmless to humans, animals, fixtures and IT equipment, but what's it like to experience?


Newstalk ZB journalist Andrew McMartin knows: he took part in a fog cannon demonstration last year.

'It's a feeling unlike anything I've ever experienced'

A loud hissing sound erupts, and a thick white fog envelops around me.

Within seconds, I can't see my own legs and my vision is limited to no more than 20cm.

It's a feeling unlike anything I've ever experienced: eerie, unsettling and disorientating - like a bizarre, whiteout snowstorm, without the chill.

The fog thickens even further, so much so it dampens my voice and muffles the sounds around me.

I lose all sense of direction.

Having been on the receiving end of a fog cannon - purely for journalistic purposes - I can attest to their effectiveness.

Testing the device in an empty, medium-sized room, I trigger the cannon manually with a handheld remote.

The sound alone would be enough to scare most criminals away.

It takes around 30 seconds before the entire room is engulfed. Before long I can barely see my hands in front of my face.

Not being able to see my feet, I have to shuffle along the floor as I search for the exit.

Having been prepared for the experience, I can only imagine what it would feel like to encounter the device in a small, cramped dairy full of obstacles.

Proving incredibly effective overseas, fog cannons have been embraced by a growing number of New Zealand retailers, and it's easy to see why: competing against them is virtually impossible.

Protecting staff and stock, fog cannons are relatively cheap, easy to install and they stop criminals in their tracks.

You can't steal what you can't see.