The cannons, which release up to 700 cu m of fog within 60sec, were installed as part of the aggravated robbery initiative aimed at dairies, liquor stores and petrol stations.
The initiative began in June 2017 with a Government investment of $1.8 million.
Originally, small businesses were required to pay 50 per cent of the cost of the extra security items, which included fog cannons, DNA micro-mist spray and sound barriers.
However, this was changed due to a lack of participation, with businesses only being required to pay $250 to have a fog cannon installed, with DNA micro-mist spray and sound barriers no longer being included.
Now police have revealed at least 40 businesses in Canterbury have participated in the initiative.
Ten other businesses were approached but chose not to participate.
“Fog cannons are a significant deterrent to aggravated robberies because they create an effective no-go area for offenders.
"They are unable to see anything inside the shop and it also allows employees to retreat to a safe place away from the risk of attack,” he said.
Mr Nash said he is looking at ways to roll out the scheme to more businesses this year.
Christchurch businesses have been hit by many aggravated robberies recently, with a spate of about 10 in August and September last year. An organised group of youths were allegedly carrying out some of the robberies as part of an initiation to be in the group.
One store hit was Buns Bakery on Ferry Rd, which has a fog cannon installed.
In March 2017, 15 people were arrested after Night ‘n Day on Ferry Rd in Woolston was robbed 10 times in eight months.
Last month, a knife-wielding man got the fright of his life when he entered the St Kilda dairy in Dunedin about 12.50pm, only to discover it had been fitted with a new fog cannon.
