The hidden operational risks created by combustible dust

Combustible dust can create serious fire and explosion risks across manufacturing environments but is still frequently underestimated within day-to-day operations.

Dave Heathcote, Industrial Vacuum Specialist at Nilfisk, explains why manufacturers need to treat effective dust control as part of wider operational safety management.

Combustible dust is one of the most underestimated operational risks in manufacturing, partly because it develops gradually within everyday processes.

Unlike more visible hazards, dust accumulation can become normalised over time, particularly in busy production environments like food manufacturing where dry materials are handled continuously.

Health and Safety Executive (HSE) guidance recognises combustible dust as a serious risk across the manufacturing sector.

This is reflected in HSE’s new dry cutting engineered stone guidance, supported by IOSH. However, dust control is still frequently approached as a housekeeping issue rather than a process safety concern.

As production conditions change, manufacturers need to understand how dust behaves across a site and whether existing control measures continue to reflect current risks.

Combustible dust should be treated with the same level of discipline as any other fire or explosion hazard, as it is often at its most dangerous when accepted as part of normal production activity.

Hidden dust hazards in manufacturing

One of the reasons combustible dust is often overlooked is because many of the materials involved are handled routinely and don’t appear dangerous in day-to-day operations.

Within the food industry, for example, combustible dusts can include wheat, flour, sugar, powdered milk, starch and coffee, all materials used routinely in production that don’t always attract the same level of caution as flammable liquids or gases.

Any manufacturer handling dry powdered ingredients should consider whether combustible dust is being generated during production and how the associated risks are being controlled across the site.

A thin layer of dust on a machine surface may be cleaned away and quickly forgotten, but the greater concern is often what remains out of sight.

Fine particles can accumulate upon overhead areas like extraction pipes, which are difficult to routinely inspect during daily operations.

High-level cleaning is therefore an important part of combustible dust management, particularly in production environments where dust can build gradually above the normal line of sight and later become airborne again through activity within the workspace.

Cleaning methods can increase risk

Cleaning is often treated as the solution to dust, but poor cleaning practices can redistribute the hazard.

Dry sweeping can disturb settled particles and put them back into the atmosphere. The surface looks cleaner, but the risk has just moved.

Once fine dust becomes airborne, the nature of the hazard changes significantly. Some hazardous dusts settle quickly, but others do not.

In high-energy manufacturing environments, combustible dusts can remain suspended in the air long after the process that generated them has ended.

Without effective capture, particles can continue to circulate through a workspace and expose workers beyond the immediate task itself.

In these conditions, cleaning strategies and schedules should reflect how dust behaves within the workspace and focus on preventing hazardous particles from accumulating or being redistributed through routine activity.

The limits of filtration in combustible dust environments

Dust should be captured and disposed of in a way that does not create additional risk.

Achieving that depends heavily on equipment specification. Industrial vacuum and extraction systems used in hazardous dust environments need to reflect how they will actually be used on site.

In ATEX-classified zones, equipment must be suitable for explosive atmospheres. Where hazardous dusts are present, filtration and material collection methods should also be considered as part of a wider dust control strategy.

A common mistake is assuming that a high-efficiency filter automatically makes a system safe for combustible dust environments.

Filtration is important, but it is only one aspect of effective dust control. If airflow is inconsistent or static is not properly managed, hazardous dust can still spread during collection or disposal.

Effective dust control ultimately depends on how extraction systems perform under real operating conditions, not simply the filtration specification listed on paper.

Managing combustible dust beyond compliance

DSEAR, ATEX and COSHH establish the regulatory requirements for combustible dust management, but effective control depends on how dust risks are managed within daily operations.

During busy production periods, dust control can quickly become inconsistent where responsibilities are unclear, or procedures are not regularly reviewed.

Maintaining effective control requires clear ownership, with operational teams understanding where responsibility sits and how combustible dust should be managed in practice.

Training also plays an important role in reinforcing good practice across daily operations.

Sites typically manage combustible dust more effectively when cleaning is treated as a control measure rather than a maintenance task.

For more information about IOSH, visit: Institution of Occupational Safety and Health | IOSH