Controlling hazards in the workplace is one of the main duties of health and safety professional. The COSHH regulations updated in 2002 (Health and Safety Executive, 2002) help to provide a framework by which different substances and hazards can be controlled. One of the main hazards that is presented in the COSHH regulations, is respirable dust.
Respirable dusts, defined by the World Health Organisation (1999) as “solid particles ranging in size from below 1 µm up to around 100 µm”, have the potential to cause damage both in the long and short term to worker health. Managing the exposure to dust, then, is critical to good health and safety management.
In this article, we look at the different types of dust that are defined under the COSHH regulations, and the different activities that they can be produced as a by-product by. Research suggests that construction is one of the main industries in which hazardous dust is often a problem (Flanagan, et.al 2003).
What are the main respirable dust hazards defined under COSHH?
Different activities often produce different types of respirable dust depending on the materials and equipment used. The COSHH regulations are designed to encompass a wide scope of materials to allow for the most protection. Table 1 shows a breakdown of some of the most common types of respirable dusts that can be present in the workplace.
| Type of Dust | Examples |
| Mineral Dusts | Silica, Processed materials |
| Chemical Dusts | Pesticides, bulk chemicals |
| Metallic Dusts | Lead and cadmium |
| Organic Dusts | Wood flour and cotton |
| Biohazards | Moulds and spores |
Table 1: Types of Respirable Dust (World Health Organisation, 1999)
Are ‘nuisance dusts’ worth considering when managing through COSHH?
In addition to the individual types of dust categories, broader categories can also be applied to help with their management. The term ‘nuisance dust’ is applied to substances that contain less than 1% quartz. The study by Mody and Jakhete (1987) looked at the impact of nuisance dusts concluding that the damage can often be reversible due to the little impact they had on lung performance.
This theory has been challenged by Cherrie, et al (2013) who draw upon various studies linking the exposure to low toxicity dust to long term health conditions, notably in miners. This, amongst general modern medical research, indicates that the term ‘nuisance dust’ is potentially outdated.
The construction industry and exposure to respirable dust
Different operations in workplaces can have the capacity to produce or disturb dangerous respirable dust. One industry that comes to mind for many is construction. Activities such as demolition, stone masonry, and carpentry all have the potential to produce dangerous dust.
The study from Lumens and Spee (2001), looked at the factors that determine the exposure of respirable quartz dust in construction. The findings of the study produced notable results. 3 population types were analysed in construction: Recess millers, inner wall constructors, and demolition workers.
Of the workers, the highest exposure to respirable dust was shown in the demolition workers. The findings align with that of Yassin, Yebesi and Tingle (2005) which indicate that construction workers are equally exposed to silica dust, even though exposure levels have reduced in recent years.
The nature of the work and exposure to respirable dust
The nature of the work and the environment it is conducted in is also a factor in the level of exposure within the industry. In areas without natural ventilation, the exposure to hazards is likely to be much higher, even if the amount of dust produced is consistent with outside work. This may suggest that those working on internal construction projects or in tunnelling will be more exposed to the dangers of respirable dust. Table 2 shows the tools used by the workers in the Lumens and Spee (2001) study.
| Recess milling | Double diamond saw with LEV
Conventional recess miller with LEV Conventional recess miller Specially designed clipper |
| Inner wall construction | Electric saw
Fork-lift truck with shovel |
| Demolition work | Broom
Sledgehammer Electrically or pneumatically driven jackhammer |
Table 2: Overview of equipment used in the 31 studies construction sites (Lumens and Spee 2001)
The extent to which the hazards of this dust is managed correctly may vary from site to site. Indeed, interviews conducted in Lumens and Spee (2001) study shows that many construction workers felt the presence of the dust was unavoidable in many circumstances (perhaps highlighting the need for constant PPE usage).
Other industries where respirable dust can cause danger
Whilst numerous studies look at the exposure of hazardous dust in construction, other industries also exhibit the same danger. Equally as shown by the study of Lumens and Spee (2001) the nature of the work and variable environments in each industry can also lead to different levels of dust exposure.
A lot of different job roles have the potential to expose dangerous respirable dust. Food preparation, for example, could lead to the emittance of flour which if repeatedly inhaled over time could lead to damage. Table 3 shows some of the potentially affected industries and the different types of dust that could be present.
| Industry | Dust type |
| Agriculture | Biohazards |
| Pharmaceutical | Chemical dusts |
| Food catering | Organic dusts |
| Mining | Mineral dusts |
| Manufacturing | Metallic dusts |
Table 3: Industries affected by different types of respirable dust
What can you do to ensure we minimise respirable dust exposure?
As shown respirable dust comes in a variety of forms and can be produced through the routine work of many different activities in construction and other industries. Controlling exposure through following the COSHH principles will help you manage the exposure to the hazards and keep workers safe. This can come in the form of proper PPE usage and good general safety practices.
REFERENCES
Health and Safety Executive 2002, Control of Substances Hazardous to Health 2002 (COSHH), 22 April 2020, (https://www.hse.gov.uk/nanotechnology/coshh.htm)
Mody V Jakhete R. 1987 Dust control handbook for minerals processing. Denver, CO: U.S. Bureau of MinesAvailable at http://www.osha.gov/dsg/topics/silicacrystalline/ dust/dust_control_handbook.html. Accessed 10 October 2012.
John W. Cherrie, Lisa M. Brosseau, Alastair Hay, Kenneth Donaldson, Low-Toxicity Dusts: Current Exposure Guidelines Are Not Sufficiently Protective, The Annals of Occupational Hygiene, Volume 57, Issue 6, July 2013, Pages 685–691, https://doi.org/10.1093/annhyg/met038
Yassin, A., Yebesi, F. and Tingle, R., 2005. Occupational exposure to crystalline silica dust in the United States, 1988–2003. Environmental health perspectives, 113(3), pp.255-260.
Lumens, M.E. and Spee, T., 2001. Determinants of exposure to respirable quartz dust in the construction industry. Annals of occupational hygiene, 45(7), pp.585-595.
World Health Organisation (1999), Hazard prevention and control in the work environment: Airborne dust (WHO, 1999), 22 April 2020, https://www.who.int/occupational_health/publications/airdust/en/
Flanagan, M.E., Seixas, N., Majar, M., Camp, J. and Morgan, M., 2003. Silica dust exposures during selected construction activities. AIHA Journal, 64(3), pp.319-328.
