Responders from the Hampshire & Isle of Wight Fire and Rescue Service swooped on the supermarket on Church Litten, Newport. Shoppers were evacuated from the building around 12.20pm.
Fire fighters used ventilation fans to rid the building of noxious gases, and a cordon has reportedly been erected around the scene.
The incident was cleared shortly after 1.20pm.
In a statement, the fire service said that the alarm had been sounded shortly after midday, with firefighters from Newport and Ryde, a coastal town, attending.
A spokesperson told Express.co.uk: “With the store evacuated, crews investigated to find a small amount of refrigerator gas had leaked.
“HIWFRS ventilation fans were used to clear the store of gas before the stop message came in at 1.23pm.”
Local outlet Island Echo said that around 900g of refridgerator coolant had leaked after a unit had been moved in the store.
The supermarket sits to the south-west of the town, beside the River Medina.
Newport is the county capital of the Isle of Wight, which sits of the south coast near Portsmouth and Southampton.