Flour power

One Saturday in October 2007, Shirley Labelle was working overtime in a very large bakery plant in southern Ontario when she couldn’t get sufficient oxygen into her lungs.

“It took up too much oxygen to even move; even to raise my arm, it was too much. I was just basically standing there and it was getting worse,” she says. “I was petrified. I said ‘I’m healthy what’s going on?’”

Things didn’t get much better over the weekend, so first thing Monday morning she went to see her doctor and her breathing test showed obvious impairment. Her doctor originally diagnosed her with emphysema, but Labelle wanted to get a second opinion. After about three months of testing with various specialists, she was diagnosed with baker’s asthma, an occupational respiratory disease that can occur in bakery workers.

The signs and symptoms of baker’s asthma are the same as those who suffer regular asthma: coughing, shortness of breath, tightness in the chest and wheezing. After 17 years of working in the bakery, Labelle’s first sign of the disease was a non-productive cough.

“It came on like a sneeze, it was that fast. Because it was non-productive, you continually have that itch there to cough all the time,” she says. “That was continuous for months.”

Breathing in flour dust and other substances common in traditional bakeries, larger commercial plants or flour mills causes baker’s asthma. Examples include:
• ?flour and grains (wheat, rye, barley, soy and buckwheat)
• ?additives, improvers, emulsifiers, enzymes (alpha amylase)
• ?other allergens (yeast, eggs or egg powder, sesame seeds and nuts).

Baker’s asthma is a common occupational disease in Canada and around the world. According to Michael Pysklywec, a physician at the Occupational Health Clinics for Ontario Workers in Hamilton, the prevalence is “strikingly high” with anywhere between five per cent and 25 per cent of people in the industry developing the disease.

In Quebec, flour/cereal dust is one of the top three causes of occupational asthma. In the United Kingdom, a baker is considered to be in a “high risk” occupation. A new study presented at the European Respiratory Society International Congress in September revealed flour is the number 1 cause of occupational asthma in France.

While the occupational exposure limit (OEL) for flour dust particulates varies across the country, many provinces follow the guidelines from the American Conference of Industrial Hygienists, which imparts a threshold limit value of 0.5 milligrams per cubic metre of air (mg/m3) for inhalable flour dust.

But when it comes to actual exposures, bakery workers are exposed to significantly more dust than the limits. A study of 96 bakery workers in British Columbia revealed airborne flour dust concentrations ranging between 0.1 mg/m3 to 110 mg/m3 (more than 200 times the OEL), depending on the work activity. Workers in industrial or traditional bakeries could be exposed to up to 7.8 mg/m3 and mill workers up to 16 mg/m3.

Recipe for prevention

Preventing baker’s asthma can be tricky since flour is prevalent in almost every part of a bakery. Flour and other dusts pose an inhalation hazard when weighing and adding ingredients, mixing ingredients with flour, flouring the work surface, processing the dough through turning, flouring and dividing and also when cleaning the equipment.

While the first step in the hierarchy of controls for preventing baker’s asthma is elimination, this is virtually impossible in a bakery that needs certain specific items to make its final product.

The next step is to try and substitute the asthma-producing products but this can be a challenge in a bakery as well.

“It’s really hard for a baker to change the flour because the recipe is usually their own; it’s always a special recipe and according to a certain kind of bread or certain kind of pastry, you really have to use a certain kind of flour,” says Simon Aubin, an industrial hygienist at the Institut de recherche Robert-Sauvé en santé et en Sécurité du travail (IRSST) in Montreal.

If possible, some substitution options include liquid enzymes, granulated (instead of powered) improvers and organic flour.

“The more the flour dust is small in terms of particle size, the more it’s going to be easier to get suspended in the air,” says Aubin. “If you use more organic flour, which hasn’t been processed too much in the mill, the particle size will be bigger and it would be a bit less of a problem.”

Controlling the level of flour dust can be achieved by enclosing dusty machinery. For example, a tight lid should be put on the mixer at the very beginning when the flour is dry.

“During the first minute, you have to start at a very, very low speed, otherwise you will have an amazing amount of dust in the air,” says Aubin.

Installing a local exhaust ventilation system, which removes the contaminant before it spreads through the workplace, is also very effective. Mixers should be retrofitted with an exhaust system that is placed behind or beside the mixer, rather than above.

WorkSafeBC offers the following additional tips for local exhaust ventilation control:
• ?Flour and ingredient weighing should be performed in ?ventilated cabinets.
• ?Bench-top extraction systems should be retrofitted to dough brake tables.
• ?Stand-alone dust collectors can also be used for a variety of tasks.

Excellent general ventilation is necessary. A good system of fans and exhaust that can adjust the air flow and achieve several air changes per hour can make a big difference, says Aubin.

Regular air testing should be done at bakeries. This was a problem at Labelle’s plant as it went “quite a few years with no testing done whatsoever,” she says.

“For any place that works with anything like that, that’s airborne, even though you cannot see it, it’s there and you need to ensure your ventilation is proper and if you have to change the filters… that procedure needs to be followed,” says Labelle. “If it has no place to get out and no proper ventilation, then it stays in the air.”

As the last line of defence, proper personal protective equipment (PPE) should be provided to workers. For example, a N95 filtering half-face piece respirator is recommended to protect against dust, while a surgical mask is not. But the use of a mask should be temporary, just until the ventilation can be improved, says Aubin.

Kneading safe ?work practices

Good work habits can help prevent exposure of flour and other dusts — or at least reduce the duration or intensity of exposure — in bakeries.

“They have to care about the levels of dust in the air and in order to do that, you need to pay attention to the way you work in your bakery and make sure you do not put flour dust in the air for nothing,” says Aubin.

For example, the way workers empty bags of flour into a mixer is one of the main causes of flour dust in the air, according to an IRSST study.

“Sometimes the mixer is really big and they transfer 50-pound bags into the mixer several times in a row and if they don’t pay attention, it will create huge clouds of dust,” says Aubin. “Those clouds don’t last very long, but it is still quite an exposure of dust for a few minutes.”

To reduce the dust, a worker can empty the bag slower and in a more delicate way.

Workers need to adopt good housekeeping methods as well. They should keep the premises clean after the task or every day, depending on the level of production. They should not dry sweep flour dust, but rather use HEPA vacuums for cleaning up spills.
There might also be new pieces of machinery or tools that can reduce dust exposure. For example, bakeries could use dredgers or sprinklers to spread flour rather than dusting by hand — but that might also require a culture shift in traditional bakeries.

“Even though they are taught to at school, the traditional way of doing baking would be throwing handfuls of flour on the counter and that would cause lots of dust suspension in the air, so that would be the thing to make them aware that you have to change that mentality,” says Aubin.

Bakery workers need training on work-related asthma and its signs and symptoms because they will often be the first to identify the problem, says Pysklywec.

Employers can also monitor employees for signs and symptoms of asthma to detect the disease early and assist in secondary prevention.

“Ideally, employers will have some sort of surveillance to monitor workers for potential early signs or pre-clinical signs of breathing issues,” says Pysklywec. “You might find breathing issues before the person even knows it’s a problem.”

Employers should conduct regular breathing tests for all workers. The tests are conducted and interpreted by trained health-care professionals to measure a patient’s air flow. The test is brief and noninvasive — it simply involves blowing into a tube.

If a worker is exhibiting symptoms of baker’s asthma, the employer should remove her from the areas that have exposure to flour dust and find her another job, says Pysklywec. Theoretically, that person is allergic to something in the workplace and has to eliminate exposure to that sensitizer from here on in. This is different than what is commonly seen in health and safety where the response would be to engineer the exposure down.

“You can’t just say ‘Well, you can keep working on that line, just make sure there is a fan near you.’ That doesn’t work for these people because if you’re allergic to something, you are very reactive to even low levels of that exposure,” says Pysklywec.

If a worker’s symptoms develop into asthma, to determine if the asthma is work-related, the worker goes into a specialist to take breathing tests when he is away from work for two weeks and then takes them again when he is at work for two weeks to see if there is a difference, says Pysklywec. In addition to the regular tests, patients are given a peak flow meter they can breathe into and record their results. It is patient-operated and they’re encouraged to do it up to four times per day with readings at and away from work.

Whether it is a proactive, preventive approach or a reaction to a baker’s asthma diagnosis, there can be significant challenges with accommodating these workers. In a bakery, the only place where there wouldn’t be flour exposure would be in the office, but many workers do not have applicable skills for that area.

When Labelle first had her symptoms in October 2007, she was off work for eight days. At this point, she informed her employer and the union about her condition. She also filed a claim with Ontario’s Workplace Safety and Insurance Board (WSIB).

When she went back to work in December, she was working in a different part of the plant that was newly built and used less flour for the product it produced. But after only one shift, not only was she having breathing problems, she was throwing up. She ended up in the emergency room one evening with a severe asthma attack and was in the hospital for seven hours. She did not go back to work for several weeks.

In January 2008, it was confirmed she had baker’s asthma. When she came back to work, her employer had to accommodate her new disease — and it resulted in a terrible experience.

“For the first year, they put me in a separate office building where I sat and did nothing and after that they got me a job outside where I was to pick up garbage and cigarette butts,” says Labelle. “And after two years, they fired me and I thanked them for it. I was stuck. I had a family to support and I couldn’t walk away.”

Labelle then changed career paths and went to college for a two-year course in social services. She has since moved out of Ontario and now works as an employment specialist for Prairie Branches in Biggar, Sask. While she is happy with this new chapter of her life, she is still plagued by her permanent disease of baker’s asthma. She takes asthma medications every day, has a puffer for emergencies, suffers asthma attacks and battles major breathing difficulties every time she sleeps.

“I have the same nightmares of drowning due to a lack of oxygen,” she says.

Looking back at that Saturday at work when she couldn’t breathe properly, Labelle regrets not seeking help right away and acknowledging the warning signs.

“If I stayed out of the plant and if they would have caught the diagnosis and sent me through right away, I probably wouldn’t have had it, but ?I just didn’t understand,” she says. “If it would have happened differently, it could have been corrected right away and I wouldn’t have asthma and nothing would have happened.”

This article originally appeared in the February/March 2015 issue of COS.