Technical and legal guidance

This page gives more in-depth technical and legal information, with links to training tools to get more help if you need it.

Definition of poultry dust

'Poultry dust' is the term used to describe the dust, including any biological agents, from work activities on poultry farms (including hatcheries).

The work activities that cause the dust include:

  • laying down litter;
  • populating poultry houses;
  • handling and inspecting birds;
  • vaccinating birds;
  • the routine upkeep and cleaning of houses during the growing or production period;
  • catching or depleting birds;
  • removing litter and/or manure;
  • cleaning houses at the end of the production period, and other related or similar activities.

Poultry dust may vary in composition from pure wood dust to a complex mixture of organic and inorganic particles, faecal material, feathers, dander (skin material), mites, bacteria, fungi and fungal spores and endotoxins depending on the type of birds, the work activity and the point in the growing or production cycle.

Some of the individual components, eg storage mites and softwood dust, are known asthmagens (substances that are capable of causing occupational asthma).

Which activities generate poultry dust?

People working in poultry houses breathe in a host of different airborne particles which collectively are referred to as poultry dust. The composition of poultry dust depends on several factors, eg the growing or production system, the type of housing, the type and age of the birds and the work activity itself. There are several typical activities that generate airborne poultry dust, capable of causing respiratory disease:

  • Laying down bedding.
  • Populating poultry houses with young birds.
  • Routine crop maintenance and cleaning.
  • Catching poultry (depopulation).
  • Litter/manure removal.
  • Cleaning poultry houses after depopulation.

Laying down bedding

  • Spreading straw/wood shavings by hand
  • Mechanical chopping and spreading straw and wood shavings

Populating poultry houses with young birds

  • Placing out trays of day-old chicks into growing sheds.
  • Transferring point of lay hens from wheeled modules into cages/open barns.

Routine crop maintenance and cleaning

  • Using an air blower to clean down battery cages, walls, floors and machinery.
  • Using a brush to sweep away debris.
  • Using a brush to clean cages.

Catching poultry (depopulation)

  • Herding birds into a penned area.
  • Walking through birds to check for bird welfare.
  • Catching birds.
  • Vaccinating birds.
  • Loading birds into modules.

Litter/manure removal

  • Using a mechanical bucket to scoop, scrape, pile up and tip litter.
  • Using a shovel to remove litter from around the base of roof supports and other awkward areas inside a poultry house where a mechanical bucket cannot reach.
  • Using a blower to remove litter from around roof supports/extensions.
  • Using a mechanical rotary brush to sweep up the floor.

Cleaning poultry houses after depopulation (final clean)

  • Using compressed air to clean extraction fan and casings.
  • Using compressed air to blow down poultry material at high level.

More detailed information on exposure to poultry dust can be found in HSE research report RR655 Exposure to dust and bioaerosols in poultry farming: Summary of observations and data.

Causative agents and their health effects

A person's response to dust depends on many factors including the nature, duration, level and particle size distribution of airborne exposures.

Poultry dust contains particles of varying size in the range c. 0.5 to 50 microns. The presence of particles in the respirable range (<5-7 microns) means that poultry dust particles penetrate into the gas exchange region of the lung. Larger particles also cause disease by impacting in the upper and larger airways below the vocal cords.

The dust, as other agricultural dusts, contains a number of allergens that cause respiratory illness. Multiple exposures are common and some exposures cause more than one specific disease.

Acute and chronic work-related symptoms are very common in poultry workers and include coughing, bring up phlegm, shortness of breath, wheezing, chest tightness, eye irritation, nasal congestion, sneezing, runny nose, throat irritation, headache, fever and fatigue. These symptoms are generally non-specific and may improve on periods away from work.

This range of symptoms suggests that poultry dust causes harm by many mechanisms including direct irritancy effects and those associated with allergy.

Health effects have been identified both for poultry dust and its various constituents. A statement of evidence describes the composition of poultry dust and its health effects more fully.

Managing exposure risks from poultry dust

Under the Control of Substances Hazardous to Health Regulations 2002 (as amended) (COSHH), employers have to make sure that employees' exposure to poultry dust is either prevented or, where this is not reasonably practicable, adequately controlled.

The following advice should help you to develop good control practice and there is further guidance in HSE's guidance document Controlling exposure to poultry dust: An occupational hygiene standard of good working practice for poultry farmers, which focuses on a range of common activities or tasks, and gives simple practical advice on how to protect workers health.

Respiratory protective equipment

In many cases, respiratory protective equipment (RPE) is still required for adequate control of exposure.

RPE should be capable of providing adequate protection and should fit the wearer properly.

The workers themselves should be involved in selecting RPE.

RPE should be manufactured to a suitable standard and be CE marked.

Face-fit testing must be carried out for all respirators that rely on a good face seal to be effective (eg disposable dust masks, half and full-face masks).

Facial hair affects the performance of close-fitting respirators so faces should be clean shaven for optimum performance. Workers with beards should be provided with ventilated hoods or visors.

All users of RPE should be adequately instructed and trained in its correct use and should be shown how to check the fit before each use.

HSE's guidance document Controlling exposure to poultry dust: An occupational hygiene standard of good working practice for poultry farmers lays down the minimum levels of protection that should be provided for a range of common activities. A local risk assessment should confirm that the standard will provide adequate protection in actual working conditions.

Health surveillance

Health surveillance means regularly looking for early signs of work-related ill health and putting procedures in place to achieve this. The objectives of health surveillance are to:

  • protect the health of individual workers by detecting, as early as possible, symptoms that may be caused by exposure to substances hazardous to health;
  • help evaluate the effectiveness of measures taken to control exposure; and
  • collect information to update knowledge of health hazards in the workplace.

Collecting simple information may lead to early detection of ill health caused by work and identify the need for improved control measures.

The earlier the health effect is recognised the better the prognosis for the sufferer.

All employees exposed or likely to be exposed to an asthmagen should receive suitable health surveillance.

The specific requirements are set out in COSHH (Appendix 3) and might involve examinations by a doctor or trained nurse.

HSE has produced simple guidance on health surveillance in Appendix 4 of Controlling exposure to poultry: An occupational hygiene standard of good working practice for poultry farmers .

Information, instruction and training

Human behaviour is critical in maintaining the effectiveness of control measures. So, employers must inform, instruct and train workers about the risks from exposure to poultry dust and the steps they need to take to protect themselves.

A range of training resources are available, including guides, posters, toolbox talks, pocket cards and other tools.

Legal requirements

Adequate control of exposure to poultry dust

Regulation 7(1) of the Control of Substances Hazardous to Health Regulations 2002 (as amended) (COSHH) requires employers to ensure exposure of their employees to substances hazardous to health is either prevented or, where this is not reasonably practicable, adequately controlled.

Poultry dust is a substance hazardous to health and may contain allergens and asthmagens as defined in the Regulations.

Furthermore, COSHH regulation 7(7) states that where it is not reasonably practicable to prevent exposure to a hazardous substance, control of that exposure shall only be treated as adequate if:

  • the principles of good practice for the control of exposure (set out in Schedule 2A to the Regulations) are applied;
  • any workplace exposure limit (WEL) is not exceeded; and
  • exposure is reduced to as low as is reasonably practicable.

No workplace exposure limit (WEL) has been set for poultry dust.

Emphasis should be placed on securing good control practice which in turn should mean exposure is reduced to as low as reasonably practicable.

Good control practice includes engineering controls such as enclosure and ventilation, systems of work and personal behaviour. For certain particularly dusty activities, suitable respirators will also be necessary. Respirators should only be used as a last line of protection to control exposure, in addition to and not as a substitute for other control measures.


The law requires employers to report cases of occupational asthma to a central point under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 1995.

Please see How to make a RIDDOR report.

Training resources

Please see the resources page.

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