A fish processing factory was evacuated following a gas leak at the plant.
Staff working at Macduff Shellfish in Mintlaw were told not to enter the building after the ammonia leak was discovered.
Emergency crews were called to the Station Road premises at about 6.23am on May 1.
Dozens of firefighters arrived at the scene to deal with the incident and police assisted by making sure no-one went inside the building.
A spokeswoman for the company confirmed it was ammonia gas that had leaked at the processing plant in Aberdeenshire.
Exposure to low concentrations of the colourless gas, which has a pungent smell, can cause coughing as well as nose and throat irritation.
No details where given on where the incident happened inside the building or what the gas is used for.
The spokeswoman said: “We had an ammonia leak that is now under control.
“We safely evacuated all of our staff from the factory and followed the safety procedures in place.”
Emergency services were still at the scene late into the afternoon, with staff gathered round the outside of the building.
A spokeswoman for the fire service said: “A call came into us at 6.23am.
“It’s a multi-agency incident – the police and ambulance services were also on scene.
“We had four appliances in attendance. It’s a hazmat (hazardous materials) situation so we will remain on scene.”
A spokesman for the ambulance service added: “We received a call today at 6.26am to attend an incident in Macduff.
“We dispatched two ambulances and our special operations team to the scene.”
The plant specialises in processing shellfish, including scallops, langoustines, crabs and whelks and is one of the largest in the north of Scotland.
Products from the factory are delivered to sites all over the world.