The province's labour department is not laying blame in the deaths of three men who were killed by liquid manure fumes.

Ron Carson was transferring waste from a sewage lagoon to a tanker truck when he was overcome by manure fumes. Two co-workers also died after they went into the tank to save him.

The investigation into the accident near Lucky Lake 2 years ago has just ended. "There's no way of assessing blame," says Carol Todd of the occupational health and safety branch. "There's no way of saying, 'It was this thing or that thing that was not done correctly.'

"All of our information indicates that Mr. Carson was an experienced operator and was unlikely to have entered that truck without the proper protection being taken before doing that."

Todd says manure fumes can render a person unconscious in seconds. She says workers have to be aware of the hazards, and trained to deal with them.

The government has reviewed safety procedures with each of the six to ten contractors in the liquid manure business.