Bakery uses low-dust flour to reduce asthma risk

Bakkavor Bread – part of Bakkavor Group – significantly reduced the risk of asthma from flour dust by using low-dust flour for dusting at its Twister Bread production line.

Previously normal flour was used, with workers needing to wear respiratory protective equipment (RPE) to prevent the risk of breathing in flour dust and developing 'baker's asthma'. Since introducing the low-dust flour, workers no longer need to wear RPE, they feel more comfortable and can communicate easily.

Historically, using normal flour, personal exposure levels to airborne flour dust were higher than the good practice value for flour dust exposure, of 2 mg/m3 (8-hour time-weighted average (TWA)). The 8-hour TWA was measured by conducting a dust monitoring survey, using a personal dust sampling method to obtain the concentration of dust the worker was exposed to. The result is then calculated to determine the average airborne dust exposure over an 8-hour shift.

With less dusting flour being used:

  • the company has seen annual savings, mainly due to a decrease in waste and an associated labour reduction through not having to remake dough;
  • the line cleaning frequency has also been reduced, freeing up hygiene staff to complete other tasks.

The Production Line Leader said: 'We use half the amount of this new flour compared to what we did before and the flour works well on our equipment.'

Substituting baking flour with low-dust flour

Since February 2017, as a result of replacing normal flour with a low-dust flour, dusting at the first conveyor line is now only required during the first and last pass of the dough through the rollers as the low-dust flour is much better at preventing dough sticking, so significantly less flour is used. Operative exposure to airborne flour dust reduced to 1.12 mg/m3 (8-hour TWA), well below the good practice value of 2 mg/m3 (8-hour TWA).

Between 2017 and 2018, further improvements were made to the process. The flour dusting dredger was adjusted, reducing the height at which the flour was dropped onto the conveyor and narrowing the width of the spread of the dusting flour. This optimised the amount of flour applied by the dredger, minimised airborne flour and reduced flour wastage. Also, on the second conveyor for the main production line, a brush attachment was used on the spreader bar to evenly distribute the dusting flour on the conveyor.

As a result, further reductions in airborne flour were made, with operative exposure down to 0.54 mg/m3 (8-hour TWA). There was a noticeably improved working environment, with much less dust in the air after introducing low-dust flour to the process.

Other benefits to the company

No need for respiratory protective equipment (RPE)

The biggest benefit is the reduced risk of breathing in flour dust and developing 'baker's asthma', combined with the improved comfort for the operatives now that RPE can be removed. While PPE/RPE offers protection, it is generally uncomfortable and used as a last resort, being able to reduce the risk at source does allow the RPE to be removed, with associated cost savings.

Lower level of health surveillance

In consultation with their occupational health provider, it was agreed that due to the current low dust levels at the Twister line, the respiratory health surveillance programme could be modified for affected workers after they have gathered sufficient data.

Providing no health issues are raised by these workers in respiratory questionnaires or lung function tests, the company will now consider removing the need for spirometry testing and instead use a health surveillance programme in the form of questionnaires carried out by a trained person.

Any future new employees will undergo health surveillance and have spirometry before any potential exposure to flour before starting the job, to ensure an accurate measure of their health when starting work is recorded and any adverse effects are detected quickly.

More information on health surveillance

Product quality

While the successful work undertaken has been shared with the company's customers, the low-dust flour is still wheat flour that has undergone hydrothermal processing, so there are no additional ingredients which would need to be declared. There is no reported taste difference in finished goods made using low-dust flour.

Minimising food waste

When using normal flour, some of the inner layers of the coiled dough would regularly stick together and could not be uncoiled. When this happened, another batch of dough had to be made and rolled out again. Changing to the low-dust flour has reduced food waste and resulted in labour and material savings.

Reduced cleaning time

The frequency of using a full wet clean of the conveyor line to remove sticky dough residue has been reduced. Cleaning benefits include:

  • using a vacuum cleaner is quicker, easier and cleaner than the previous wet clean process
  • cleaning production equipment is now much faster with no sticky dough remaining on the conveyor belt
  • reduced frequency and depth of hygiene cleaning operations (including walls) and high-level cleaning to remove settled dust

Reduced maintenance

A reduction in equipment failure and breakdowns has been noted as there are less flour particles to gain access to bearings etc.


The use of low-dust flour has reduced the risk of breathing in flour dust and developing baker's asthma, as well as improved the overall working conditions for the line operatives.

This case study highlights how using industry knowledge can identify suitable control solutions to protect workers' health and provide additional benefits for the company.

Bakkavor will therefore be reviewing the use of low-dust flour in its other operations where economically viable. Although there has been an additional cost for low-dust flour over regular flour, annual net cost savings have been made.

Note - Smaller bakeries without automated processes can also use low-dust flour when dusting surfaces to prevent the dough sticking and to reduce workers' exposure to flour dust.

Baker and flour dust


A 51-year-old maintenance fitter worked at a bakery for about 20 years. He did not smoke or have any history of asthma before he started work.

He complained of breathlessness, wheezing and coughing. This had been getting gradually worse during the past 15 years.

At work, his eyes often became red and watery. He had sneezing attacks. His symptoms were not affected by the season of the year. But he noticed that they improved when he was away from work.

A chest physician had previously diagnosed the fitter with asthma but had not connected this with his work. It was the trade union representative who suspected occupational asthma.

HSE investigation

A series of tests showed that his lung function was considerably better at weekends and on holiday. Further tests indicated a flour dust allergy.

As a result of these investigations, management arranged for him to work in less dusty areas of the plant. They improved the dust extraction and issued him with suitable respiratory protective equipment (RPE).


He remains at work using RPE to reduce his exposure, and medicine to improve his symptoms. However, his general respiratory health is poor because of chronic asthma, for which he receives disablement benefit.

Investigations revealed that this was not the only victim. Two further cases of flour dust allergy were detected.

These workers have better health, because their developing asthma was picked up more quickly. However, they still need medication to control their symptoms. And they are likely to suffer from breathing problems for the rest of their lives.

The Your trade section of this site provides top tips and advice on how to protect yourself if you are a baker or work with flour.

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