WorkSafeBC is advising heliski guides to wear better ear protection from noise.
"Noise, like a lot of hazards, is dose based," explained the agency's occupational audiologist Sasha Brown.
"The louder it is the less time you can spend around it."
WorkSafeBC wants guides to make sure they wear ear protection when on or around helicopters.
In 2013, WorkSafeBC clarified some guidelines, making helmets a requirement for guides.
Now the organization wants to make sure that heli guides know that helmet ear flaps are not strong enough for noise protection, and what is needed are proper noise-cancelling ear muffs.
"It's introduced an unexpected dilemma," said Brown, explaining that some guides felt like they had to choose between helmets and ear protection.
Exposure to noise above 85 decibels can cause permanent hearing loss—and helicopters can produce noise levels that are significantly higher than that.
A 2016 study by industry association HeliCat Canada laid out the noise levels produced by various helicopter models, giving the amount of time that can be endured before damage is caused to the ear.
A Bell 212, for example, produces an estimated noise level of 102.4 decibels, leading to a "maximum daily unprotected exposure time" of eight minutes and 37 seconds.
Thankfully, the damaging effects can be countered with proper hearing protection, said WorkSafeBC.
Getting guides to put on ear protection right away wasn't an easy ask, however, as many guides weren't used to wearing any.
According to Ross Cloutier, executive director of heli-ski trade association HeliCat Canada, there has been a cultural shift in the last 10 years, with guides recognizing the need to wear it.
"I would say that today, because this is a WorkSafe directive, and businesses are obliged to educate their workers and provide hearing protection and have a policy, it's normal for people to wear ear protection," said Cloutier.
"As ski guides we're working around these helicopters all the time. It's really loud, and some people have probably had impacts from that."
Cloutier said that the preferred method for guides is over-the-ear protection, which can be used in coordination with a thin beanie and a helmet with no earflaps.
"The problem with things like ear plugs is you're outside in the winter, and you've got big gloves on, so in order to put them in and take them out, you'd need to take your gloves off every time," he explained.
"The over-the-ear protection is pretty practical. I can put them on, and take them off with my gloves, and I can just clip them onto my back. They work."
In order to get proper protection, guides need at least class B-rated hearing protection, found the study.
"The noise created by all helicopters is above the acceptable WorkSafe threshold and will impact hearing loss," said Cloutier.
"Workers should be wearing hearing protection around helicopters."