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Health risks in small bakeries: exposure to flour dust and enzymes


This operational guidance is about reducing the number of cases of occupational asthma in small and medium size bakeries by controlling exposure to flour dust and enzymes.   


HSE statistics on occupational asthma (as reported by chest physicians) indicate that bakers are the second most at risk occupational group. Exposure to flour dust and enzymes contained in improvers may also provoke an asthmatic attack in individuals with pre-existing asthma.

High airborne flour dust levels are generated when flour is hand dusted or sprinkled, brushed, blown or vibrated. The main emphasis is to reduce exposure at source by promoting the careful handling of flour and avoiding practices that cause flour to become airborne.


Inspectors should assess if bakeries provide effective control measures to reduce airborne emissions at source to reduce exposure to flour dust and enzymes when they inspect a bakery.

Inspectors should undertake an inspection of a bakery when bread and pastry products preparation is in “full swing” (Note: this may be in the early hours of the morning).

While every bakery is different, inspectors should focus on the dusty tasks:

Adequate control of airborne flour dust may not be achieved by single good working practices. For specific dusty tasks, a combination of control measures should be in place to reduce workers exposure to airborne flour dust, such as:

The range of issues and controls are outlined in flour dust COSSH essentials direct control sheets for small craft bakers. They can be accessed at the COSHH baking pages.

Inspectors should ask to see the company’s health surveillance records, the COSHH risk assessment (if the company employs more than five people) and the test records for examination and test of local exhaust ventilation (LEV) (as required under COSHH regulation 9).  

For inspectors, the Enforcement Management Model (EMM) (see Appendix 1) should be used to determine the appropriate action to take when they have formed their opinion that there is a non compliance or a contravention of a regulation.


Bakeries can be a high risk working environment in relation to occupational asthma. Historical data suggests that 95,000 employees in total work in the baking industry, 27,000 of which could potentially be exposed to flour dust and enzymes. There are approximately 4000 small/medium size bakeries in the UK and the level of exposure to flour dust will vary depending on bakery size and the control practices will vary amongst bakeries.

Flour dust and enzymes in improvers are hazardous substances as defined under the Control of Substances Hazardous to Health (COSHH) Regulations 2002. The Workplace Limits (WEL) for flour dust (inhalable dust fraction) are: 10 mg/m3 8-hour TWA and 30mg/m3 15 minute short term exposure limit.



National Local Authority Enforcement Code – bakery premises regulated by Local Authorities inspectors are not subject to proactive, unannounced inspections unless there is a reason to suspect poor performance

If identified as a priority sector the following SIC codes should be used to identify premises:  5224 Retail bakeries; 1581 Manufacture of bread, fresh pastry and cakes; 1582 manufacture of biscuits, preserved pastry. Search SME’s employing up to 9 employees and mediums size employing between 10-49 employees.

Recording & Reporting

No special reporting arrangements apply.

Health & Safety

Inspection of bakery activities has potential to expose visiting staff to risks to their health and safety.  Inspectors are reminded they may be entering a dusty environment containing asthmagens and may require suitable PPE/RPE.

Further References

Further guidance not already linked or referenced includes:


OPSTD - Food/Drink Sector

Long Latency Health Risks Division - Respiratory Interventions Unit

FOD Specialist Inspector - Occupational Hygiene Unit

Appendix1 - Enforcement Management Model (EMM) - Enforcement is likely to be under COSHH regulations 2002

Observation/Regulation Initial Enforcement Expectation (IEE) / Action

COSHH assessment absent

COSHH Regulation 6 (assessment). Factors to be considered:

  • reference to the hazardous properties and health effects of exposure to flour
  • description of activities that lead to exposure including level, type and duration of exposure
  • number of employees or groups exposed
  • reference to the Workplace Exposure Limits
  • description of control measures and their effectiveness inc. RPE
  • results of airborne monitoring (if any)
  • results of health surveillance
  • review date

>5 employees
Written COSHHassessment required

< 5 employees
COSHH ACOP – occupiers are strongly advised to record significant findings of assessment

Action/IEE – IN/letter seeking evidence that company has systematically considered factors liable to produce exposure and to demonstrate that controls in place are effective

COSHH Regulation 7.7 (a)

Inspector observes flour being used extensively (>2 hours total) as a lubricant (hand dusting) on table, dough brake, divider or tray without care or training;

Powder improvers also used.

Dust control measures identified as not adequately controlling exposure to potential asthmagen.

Risk gap - extreme

Action/IEE – IN for control and also an IN for training if no training provided to employees working with flour dust and improvers.

COSHH Regulation 7.7(a)Schedule 2A

Principle (h) Controls measures should not increase overall risk

Occupier to consider other risks when new controls provided e.g
Enclosures/LEV/vacuum may increase explosion

Action/IEE – letter Risk Assessment
COSHH Regulation 9 – Maintenance, examination and testing of LEV

LEV not maintained and indentified to be in obvious need of repair. Action/IEE – IN

Thorough examination and test of LEV systems not carried out. Action/IEE - IN

COSHH Regulation 10 – Monitoring exposure

Personal airborne monitoring may be required to show that WELs have not been exceeded (method as described in HSE guidance MDHS 14/3 “General methods for sampling and gravimetric analysis of respirable and inhalable dust”)
*for personal monitoring, records should be kept for 40 years

Dust lamp (MDHS 82) can be used to highlight exposure to flour dust in the event of poor work practices


Action/IEE – monitoring not normally required when principles of good practice have been implemented

Letter/IN Monitoring required where evidence of poor control or reliance is wholly on good work practice when handling flour >2 hours per shift

COSHH Regulation 11 – Health Surveillance

Health surveillance is appropriate  where exposure is to a respiratory sensitiser such as flour dust or enzymes contained in improvers

Action/IEE – IN

Absence of health surveillance (except for self employed)
Updated 2015-09-14