The Winnipeg Fire Services hazardous materials response unit spent hours trying to clear a potentially lethal amount of ammonia from a business Saturday evening.

Naleway Foods in the Inkster Industrial Park was evacuated Saturday when a large ammonia leak was discovered in a freezer area.

The hazmat unit spent a large chunk of time trying to safely release the chemical into the air.

Fire officials said the vapour was more of an irritant but could be poisonous in large amounts.

Everyone made it out of the business safely, without coming in contact with the vapour.

Food inspectors were also on scene investigating.

The cause of the incident is not yet known.