WorkSafeBC officials had investigated at least two cases where toxic gases had knocked mushroom-farm workers unconscious before three people were killed at a Langley mushroom farm in September 2008.

Despite the previous incidents in 2006 and 2008, no broad warning was issued to the province's five companies that produce mushroom compost or the 40 farms that use it.

On July 24, 2008 - six weeks before the fatal incident in Langley - a Central Composting employee was hospitalized, overcome in the composting barn by deadly fumes including ammonia and methane in an oxygen-depleted environment in Abbotsford.

Along with an ambulance, two WorkSafe officials attended the incident at 830 Lefeuvre Rd., according to inspection reports obtained by The Vancouver Sun under an access to information request.

A stop-work order was issued over fears that gases in the composting barn and its bunkers presented a risk of injury, serious illness or even death.

The next day, work resumed when officials returned to the site and deemed the imminent risk to employees had passed.

The WorkSafeBC inspectors noted the worker who fell ill was likely dehydrated, exposed to toxic gases and not properly equipped with a respirator. They also found Central Composting lacked an "exposure control plan," a long-standing requirement for workplaces with harmful air contaminants.

Composting facilities regularly produce hydrogen sulphide, ammonia, methane and carbon dioxide.

Numerous other safety violations were cited at Central Composting. The farm had no occupational health and safety program; workers were not wearing properly fitting respiratory equipment; and there was no safety program to manage hazardous chemicals.

Nearly two years before the incident at Central Composting, in June 2006, a contractor was injured when overcome by methane after climbing into a tank at nearby Mountainview Mushrooms, which was found to be lacking first aid procedures as well. No further details were available, except that it took that company four years to achieve compliance.

It wasn't until after the fatal incident in Langley that officials took a close look at safety in the mushroom industry.

On Sept. 5, 2008, Han Pham, Ut Van Tran and Jimmy Chan, workers at now-bankrupt A-1 Mushroom Sub-stratum Ltd., were killed after breathing in hydrogen sulphide and ammonia while in a pump shed at a facility in Langley. Michael Phan and Thang Tchen survived but with severe brain damage.

The deaths prompted a two-year investigation and a coroner's inquest, and a trial of the companies involved.

- Zoe McKnight and Gordon Hoekstra are reporters with the Vancouver Sun

ù More at www.langleyadvance.com

WorkSafeBC inspected the province's five mushroom composting facilities and close to 40 white mushroom farms. It also renewed enforcement of the Workers' Compensation Act regulation requiring employers to create and maintain an exposure control plan to educate workers on safety when there are toxic gases in the workplace.

A now-retired B.C. environmental worker, who also had a role in monitoring the farms, said the previous incidents should have raised a "red flag" for regulators and industry.

Linda Vanderhoek, who worked for the Ministry of Environment for 37 years before retiring in January, said she regularly visited both A-1 Mushrooms and Central Composting as an environmental protection officer. She knew about the problems at the Langley farm but was shocked to learn a worker had previously fainted at Central.

She said a "heads-up" from Work-Safe to inspectors and industry would have been helpful, to send a message the job sites could be unsafe.

But there's no formal mechanism to relay the information, especially across departments, Vanderhoek noted. "Each agency has their own mandate and there should be better communication among us, I guess."

It should have been "a red flag for something that killed people six weeks later," Vanderhoek said.

WorkSafeBC said there was no reason to suspect the industry had wide-spread problems after the worker became ill at Central Composting.

"The jobs being done were completely different. Everybody knows there's gases produced at those types of job sites, but you wouldn't have been able to infer from one that the other would be hazardous. It was a different set of circumstances," said regional prevention manager Burt Goulding.

Workers at A-1 Mushroom were in a confined space - the pump shed - with no understanding of the risks posed by hydrogen sulphide, and few safe work procedures were in place overall.

At Central Composting, workers were completing daily tasks when one entered an oxygen-depleted building without a safety mask. But WorkSafe considered the job site generally safe.

"There was minimal attention paid to safety at the A-1 work site. The other one had safe work procedures that weren't followed properly by the workers," Goulding said. "There is a similarity in the hazards in that type of industry, yes. And the employer has to deal with the hazards appropriately. Which wasn't done in A-1's case."

But Central Composting didn't have a formal exposure control plan at the time, or even a health and safety committee. Though the employer had begun implementing both by August 2008, it was only considered compliant in June 2010, nearly two years after the fatal incident.

"After the A-1 thing happened, WCB came down and talked to us about it," said Balbir Randhawa, manager of Central Composting. "We had to do the exposure plan and we complied to all that. Before that, a lot of people didn't know about the H2S [hydrogen sulphide] gas. Even I didn't."

The injured worker recovered and still works for Central Composting, Randhawa said.

All 10 employees received better training, now wear gas monitors to ensure safe levels, and the building was retrofitted for better ventilation, he said.

Randhawa added he's proud of the company's safety precautions and there have been no serious incidents since 2008.

"We were fortunate there wasn't anything major," he said.

B.C. Federation of Labour president Jim Sinclair also said the two earlier incidents should have provided a warning to a highly unregulated industry with a low level of inspection.

"There should have been light bulbs going off all over the place because this was a problem that was going on for decades and decades around the world," said Sinclair, whose organization has tried to unionize agriculture workers.

The fact that previous incidents did not spur a safety warning from WorkSafeBC means it is important the province implements recommendations from this summer's inquest into the death of the Langley workers, Sinclair said. "It would be a crime not to."

The B.C. government has said it supports the recommendations.

Sinclair said one crucial recommendation is for employers to declare each year that they have fulfilled their provincial safety obligations. He said it will prevent companies from claiming they are unaware of unsafe workplace conditions.