Clearwater Seafoods says it has fixed ventilation problems on board its scallop fleet after crew members complained airborne particles were causing health issues, but for now that means crews are working at sea with masks.

"We've fully complied with the Occupational Health and Safety orders and the vessels are now back operating with the automated shucking equipment," said Christine Penney, the vice-president of sustainability and public affairs for Clearwater Seafoods.

"We've made some changes to the ventilation for the machines as per the OHS orders."

Last month, the Nova Scotia Department of Labour issued stop-work orders on three vessels after employees on the factory freeze trawlers complained airborne contaminants from the machinery were making them sick.

Crew members complained of nose bleeds, bloody coughs and headaches.

An official with the Department of Labour told CBC News the saws on the machines generate a fine dust, which mix with water to create "a visible cloud" in the work space.

The company had until Nov. 5 to improve the exhaust system and develop a respiratory protection program for the crew. It has until Nov. 19 to take air quality samples while all the machines are operating.

One vessel back at sea

Clearwater's Atlantic Protector, based out of Shelburne, is at sea and fully operational. Air quality tests over the next few weeks will determine whether the ventilation has improved to the point where the 20-member crew can operate safely without masks.

"The preliminary indications are positive," said Penney.

The Minister of Labour and Advanced Education praised the company's response.

"They are taking the health and safety of the workers seriously and we appreciate their co-operation," said Marilyn More.

"They've made the appropriate changes to ensure the respiratory and other safety of the workers. The company is working diligently to bring the other two ships up to code."

Automatic shucking machines were introduced on the Atlantic Guardian and Atlantic Protector vessels in 2011.

The company developed the technology itself. According to the Clearwater Seafoods website it "replaces the manual method of shucking scallops by making use of several different mechanical processes combined in a relatively compact piece of equipment that withstands the rigors of offshore fishing."