EU Compliance 6 min read
How to Manage Silica Under HSE COSHH in Practice
If HSE attention has put your silica controls under review, start with the work activity rather than the paperwork. This practical walkthrough explains how to assess respirable crystalline silica, select controls, verify exposure and close common COSHH gaps.
How to Manage Silica Under HSE COSHH in Practice
If an HSE inspection, internal audit or change in production has put respirable crystalline silica on your agenda, the question is usually practical: how do I manage silica under HSE COSHH without relying on a paper assessment? The answer is to follow the work from material selection through exposure verification, then keep improving the controls when evidence shows they are not working.
1. Define the silica-generating work
Start by listing every task that can release respirable crystalline silica (RCS), including work carried out by contractors. Typical examples include cutting, drilling, chasing, grinding, crushing, bag tipping, mixing dry powders and cleaning settled dust.
Record the material, task, duration, frequency, number of workers and equipment used. Do not describe the activity simply as “concrete work”. A short dry cut with a hand-held saw may create a different exposure profile from enclosed mechanical cutting with integrated water suppression.
Obtain current safety data sheets, but do not treat them as a complete exposure assessment. COSHH Regulation 6 requires an assessment of the risk created by hazardous substances, including substances generated by the work. The assessment should identify RCS even where the supplied product is not labelled as a separate hazardous ingredient.
For a UK construction project, a useful UK construction silica risk assessment links each task to a method statement, plant specification and responsible supervisor. It should also cover non-routine work, maintenance, breakdowns and cleaning.
2. Assess exposure before choosing controls
Use the hierarchy in COSHH Regulation 7. First consider whether the process or material can be changed. Examples include buying pre-cut products, using ready-mixed materials, selecting lower-silica products where technically suitable and replacing dry methods with wet or enclosed processes.
Next specify engineering controls. The preferred arrangement is usually a combination of water suppression, on-tool extraction (OTE), local exhaust ventilation (LEV), enclosure and suitable housekeeping. General ventilation alone is rarely an adequate control for a dust source close to a worker’s breathing zone.
The UK workplace exposure limit for respirable crystalline silica is 0.1 mg/m³ as an 8-hour time-weighted average, as listed in HSE publication EH40/2005 Workplace exposure limits. This is a maximum workplace limit, not a target operating level. Your aim should be to reduce exposure as far below the limit as reasonably practicable.
A task assessment should state whether exposure could exceed the limit and what evidence supports that conclusion. Use reliable occupational hygiene data, comparable task results and, where uncertainty remains, personal exposure monitoring. Area samples cannot by themselves demonstrate an individual worker’s exposure.
3. Install and verify the controls
Write the control specification into the method statement rather than leaving it as general advice. For example, state which tool must be connected to which extraction unit, when water flow must be used, how the system is inspected and what happens if the control fails.
The HSE respirable crystalline silica COSHH controls should be treated as a working system, not a list of accessories. Check the following in the order the task occurs:
- The product or process has been reviewed for substitution or pre-fabrication.
- The tool has effective water suppression, OTE or enclosure where practicable.
- Extraction airflow, filters, hoses and guards are suitable and maintained.
- Dust is not blown or brushed into the air during cleaning.
- Workers know the start-up, operating and shutdown checks.
- Supervisors can stop the task when controls are unavailable or defective.
For LEV, keep the examination and test report required by COSHH Regulation 9. HSE guidance normally expects a thorough examination and test at least every 14 months for LEV, unless a different interval is justified. Keep maintenance records and investigate repeated failures rather than simply replacing a filter.
Use industrial vacuum equipment suitable for fine hazardous dust. Dry sweeping and compressed air are common failure points because they redistribute settled silica. Use vacuuming or wet cleaning methods and control access while contaminated surfaces are cleaned.
4. Decide when monitoring and RPE are needed
Exposure monitoring should answer a defined question: do the controls keep personal exposure below the WEL for this task, shift pattern and worker group? Prepare a sampling plan that covers representative workers, normal production and the highest credible exposure conditions.
The HSE silica exposure monitoring checklist should include the task, material, tool, control configuration, sampling duration, worker identity or job category, laboratory method, flow-rate checks and interpretation against the 8-hour WEL. Document why the selected samples represent the work. If a process changes, repeat the assessment and consider repeat sampling.
Do not use respirable dust results as a substitute for silica-specific analysis unless the method can identify the relevant crystalline silica fraction. Ask the occupational hygienist or laboratory to state the analytical method and reporting limit.
Respiratory protective equipment (RPE) is an additional control, not a replacement for suppression or extraction. Where RPE is required, select an assigned protection factor suitable for the measured or reasonably foreseeable exposure, provide a clean-shaven face seal where the mask depends on one, and complete face-fit testing for each tight-fitting model and wearer. RPE users also need training, inspection, storage and a system for replacing filters or batteries.
COSHH Regulation 11 requires health surveillance where employees are exposed to a substance linked to an identifiable disease or adverse health effect and valid techniques exist for detecting the condition. Arrange competent occupational-health advice where the assessment indicates a reasonable likelihood of work-related respiratory harm. Health surveillance does not prove that exposure controls are adequate.
5. Train, supervise and review the evidence
Under COSHH Regulation 12, provide suitable information, instruction and training. Explain the health risk in task-specific terms: how dust is generated, which controls must be used, how to check them and what to do after a failure. Include agency workers, contractors and maintenance staff.
Keep the COSHH assessment, method statement, exposure results, LEV reports, equipment checks, RPE fit-test records, training records and health-surveillance arrangements together. Records should show who approved the controls and when the next review is due.
Review the assessment after an incident, failed monitoring result, equipment change, new product, complaint or enforcement intervention. A result above the WEL requires immediate investigation and interim controls; it is not enough to file the report and wait for the next annual review.
Common mistakes include sampling only the cleanest shift, treating a face mask as the primary control, omitting contractor activities and copying control wording from an old method statement. Recover by separating the tasks, identifying the worst credible exposure, checking the physical controls at the point of work and commissioning competent occupational-hygiene advice where the evidence is weak.
Closing takeaway: make the workflow auditable
So, how do I manage silica under HSE COSHH? Define the dust-generating tasks, apply the hierarchy of control, verify engineering performance, measure personal exposure where needed and maintain a traceable record of decisions. A defensible assessment is not the longest document; it is one that accurately matches the real task and demonstrates that controls remain effective.
The same approach makes later reviews faster. When HSE asks for evidence, you should be able to show the assessment, the control specification, monitoring rationale, equipment checks, worker training and the action taken when something failed.
Key facts
Machine-readable statements extracted from the sources above. Each fact keeps the same identifier across all six language versions.
0.1 mg/m³, 8-hour TWA
EH40/2005 lists 0.1 mg/m³ as the UK workplace exposure limit for respirable crystalline silica over an 8-hour time-weighted average.
Fact ID:
silica_welCOSHH Regulation 6
COSHH Regulation 6 requires an assessment of risks created by hazardous substances, including substances generated by work.
Fact ID:
coshh_assessmentCOSHH Regulation 7
COSHH Regulation 7 requires employers to prevent exposure or, where that is not reasonably practicable, adequately control it.
Fact ID:
control_requirementAt least every 14 months unless otherwise justified
HSE guidance generally expects thorough examination and testing of LEV at least every 14 months unless a different interval is justified.
Fact ID:
lev_testingCOSHH Regulation 12
COSHH Regulation 12 requires suitable information, instruction and training for employees exposed to hazardous substances.
Fact ID:
information_training
Frequently asked questions
What is the UK workplace exposure limit for respirable crystalline silica?
EH40/2005 lists a workplace exposure limit of 0.1 mg/m³ as an 8-hour time-weighted average for respirable crystalline silica. Employers should still reduce exposure as far below the limit as reasonably practicable.
Is RPE enough to control silica exposure?
No. COSHH requires employers to apply suitable controls, with engineering and process controls taking priority. RPE is an additional measure where residual exposure remains or adequate control cannot otherwise be achieved.
When should silica exposure monitoring be repeated?
Repeat monitoring when the process, material, equipment, controls or work pattern changes, or when results are not representative or indicate inadequate control. Monitoring should also be reconsidered after an incident, complaint or failed control check.
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