The president of the B.C. Federation of Labour says Friday's fatal accident at a Langley mushroom farm might have been prevented if WorkSafeBC had not dramatically cut inspections.

Three farm workers died and three were injured after being overcome by noxious fumes in a utility shed on Friday.

Federation president Jim Sinclair is questioning the WorkSafeBC investigation into the accident.

"On one hand they're doing the investigation, but they also could be part of the problem at times too, because for many years there they cut back their inspections dramatically," said Sinclair.

"There was a 62 per cent reduction in 2002 to 2006. It wasn't until three people died in a horrible accident — perfectly preventable — that they actually stepped it back up again," said Sinclair, who is calling for a public inquiry into the working conditions of farm workers.

Stan Raper, the national co-ordinator for the Agriculture Workers Alliance, told CBC News he is concerned language barriers mean many immigrants and temporary foreign workers are not being properly trained in their native language, putting them and other workers at risk.

That union is calling on provinces across the country to provide better training, support and enforcement, and for a public inquiry into working conditions for all agricultural workers across Canada.

WorksafeBC is the independent provincial agency responsible for the prevention of workplace injury, illness and disease, and the rehabilitation and compensation of those who are injured on the job in B.C.