COSHH 2002 regulation 10, UK wide
Workplace Exposure Monitoring
Adequate control of a hazardous substance stays a claim until somebody measures what a worker actually breathes. AL23 Safety scopes and manages exposure monitoring under regulation 10 of the Control of Substances Hazardous to Health Regulations 2002, interprets the results against the current workplace exposure limits and converts them into an action plan, for clients UK wide.
What is workplace exposure monitoring?
Measuring what a person breathes, not what the room contains
Exposure monitoring is the controlled measurement of airborne concentration in a worker's breathing zone over a representative working period. A calibrated pump is worn on the belt with the sampling head clipped near the collar. The filter, tube or badge is then analysed and the result is expressed as a time weighted average that can be compared with a workplace exposure limit.
That comparison is the entire point. A limit in EH40/2005 is defined in terms of the air a person breathes, averaged over eight hours or over fifteen minutes. A reading taken from a fixed point in the middle of a workshop cannot answer the question the limit asks. It can show you where a plume travels rather than whether an operator is under the limit.
Monitoring is rarely the first step. It follows the COSHH assessment and it settles the questions that inspection alone could not settle.
Who needs one
Where measurement stops being optional
- Regulation 10(1) bites where monitoring is requisite for maintaining adequate control of exposure or otherwise requisite for protecting health. Dusty, fume generating and solvent heavy work usually meets that test.
- Any process where the substance has a workplace exposure limit and control depends on ventilation performing as it was designed to perform
- Work with carcinogens, mutagens or asthmagens, where exposure must be reduced as low as is reasonably practicable rather than simply held under a limit
- Any change to the substance, the process, the enclosure or the extraction, which is an express trigger under regulation 10(3)
- Vinyl chloride monomer work and electrolytic chromium spray work, the only two entries in Schedule 5 that carry a prescribed frequency
Regulation 10(2) is the honest counterweight. Monitoring is not required where the employer can demonstrate by another method of evaluation that exposure is adequately controlled. A well evidenced control verification exercise can do exactly that. Where it applies we will say so rather than sell you sampling you do not need.
The regulations that apply
Your legal framework, in plain terms
Monitoring sits in the Control of Substances Hazardous to Health Regulations 2002, supported by the Approved Code of Practice L5 and by the limits published in EH40/2005 Workplace exposure limits. The sampling and analytical methods come from the HSE series Methods for the Determination of Hazardous Substances, shortened to MDHS. Those methods are guidance rather than law. They are also what inspectors and accredited laboratories expect to see. Departing from one needs a reason you can write down.
Regulation 10(1) and 10(2)
Monitor where it is needed to maintain or demonstrate adequate control, unless another method of evaluation proves the same point.
Regulation 10(3)
Monitor at regular intervals and whenever a change occurs which may affect exposure. No general interval is stated anywhere in COSHH.
Regulation 10(4) and Schedule 5
The only prescribed frequencies in the regulations. Vinyl chloride monomer requires continuous monitoring or a procedure approved by HSE. Spray given off from vessels where an electrolytic chromium process runs, other than trivalent chromium, requires monitoring every 14 days while the process is being carried on.
Regulation 10(5)
Records representative of the personal exposures of identifiable employees must be kept for 40 years from the date of the last entry. Every other record, static and background sampling included, must be kept for 5 years.
Regulation 10(6) and 10(7)
Where an employee is under health surveillance, an individual monitoring record is required for that person. Employees and their representatives must have access, records must be supplied to HSE on request and they must be offered to HSE on ceasing to trade.
The retention trap worth understanding
The 40 year rule is triggered by personal identifiability, not by the presence of health surveillance. If a result can be attributed to a named person, it is a 40 year record. The common shorthand that 40 years applies wherever health surveillance is running is close enough in practice, since the two duties usually travel together. It is not the statutory test. We label every record with its retention class when we hand it over so nobody destroys a 40 year record at year six.
What the service covers
Personal sampling matched to the method and the limit
- A sampling strategy built around similar exposure groups, defining who is sampled, on which task and for how long
- Personal sampling in the breathing zone, conventionally the hemisphere of roughly 300 mm radius in front of the face, using pre and post calibrated flow pumps
- Static sampling where the real question is control verification, plume mapping, background concentration or extraction performance
- Respirable, thoracic and inhalable aerosol sampling with gravimetric analysis to MDHS 14/4, the workhorse method for dust
- Respirable crystalline silica by cyclone head to MDHS 14/4 with analysis to MDHS 101/2, against the 0.1 mg/m³ eight hour limit
- Wood dust by inhalable head, applying the 3 mg/m³ hardwood limit to the whole mixture wherever hardwood is present with any other wood dust
- Welding fume as inhalable and respirable aerosol with metal speciation, benchmarked against control expectation and background because there is no exposure limit for welding fume
- Organic isocyanates in air to MDHS 25/4, with urine based biological monitoring recommended alongside for spray painters because it captures skin uptake and mask failure
- Flour dust by inhalable head in bakeries and mills, the leading cause of occupational asthma in that sector
- Volatile organic compounds by diffusive sampler to MDHS 88, with speciation where the screening result flags something
- Rosin based solder flux fume to MDHS 83/3 in electronics assembly
Our process
Scope, sample, analyse, interpret, then set the interval
- 01
Scoping and strategy
We review your assessment, walk the process and define similar exposure groups. We agree the question the monitoring has to answer before anybody books a pump.
- 02
Field sampling
Pumps are calibrated before and after the shift, with flow rates, durations and a task record logged alongside every sample.
- 03
Accredited analysis
Samples go to a laboratory holding ISO/IEC 17025 accreditation for the specific method. We confirm which parts of the work sit inside that accredited scope.
- 04
Interpretation
Results are converted to eight hour and short term averages, compared against EH40 and read against what the controls were supposed to be achieving.
- 05
Action plan and review
We set out what has to change and in what order, then agree the interval and the triggers for the next round.
What you get
Results read against the limit, then an action plan
- A monitoring report naming the method, flow rates, durations, the analysing laboratory and its accreditation status
- Individual results for every worker sampled, expressed as an eight hour time weighted average and where relevant a fifteen minute short term average
- A plain statement of compliance or non-compliance against the relevant EH40 limit or against the control benchmark where no limit exists
- Records labelled by retention class, 40 years for personal identifiable results and 5 years for static results
- A prioritised control action plan following the Schedule 2A hierarchy, not a recommendation to hand out more masks
- A recommended monitoring interval with the reasoning written down, since COSHH prescribes none for ordinary industry
What we need from you
Your COSHH assessments and access to real tasks
- Your current COSHH assessments plus any previous monitoring reports and ventilation examination records
- Task descriptions, shift patterns and typical durations so sampling covers the real working day rather than a convenient hour
- Access to workers willing to wear a pump for a full shift, with their agreement obtained in advance
- A site contact who can confirm when each monitored task actually starts and stops
Why AL23 Safety
We tell you what sits inside the accredited scope
Accountable
Where a result exceeds a limit we say so in the first paragraph, not in an appendix.
Honest about scope
Accreditation is granted method by method. We tell you whether the field sampling as well as the laboratory analysis sits inside the accredited scope. The two are frequently different.
Interpretation, not just numbers
We scope the work, appoint the right specialist, interpret the results and turn them into an action plan you can actually deliver.
UK wide
We run monitoring programmes for clients across the UK from our Manchester base, in workshops, foundries, bakeries, joinery shops and on construction sites.
Talk to us about monitoring
Find out first whether you need sampling at all
Describe the process and the substance on a call. If regulation 10(2) gives you a cheaper and better route than air sampling, that is what we will tell you. No obligation and no pressure.
Common questions
Answers, up front
Cannot see your question? Get in touch and we will answer it directly.
Contact usCost is driven by the number of similar exposure groups, the number of samples needed in each group to be representative, the analytical method behind each sample and the site time involved. Tell us the processes and the headcount and we will scope a sampling strategy rather than quote a price per pump.
COSHH sets no general interval. Regulation 10(3) requires monitoring at regular intervals and on change. Schedule 5 prescribes a frequency only for vinyl chloride monomer and electrolytic chromium spray. Annual monitoring for high hazard processes is industry convention rather than a legal requirement. What matters is that your chosen interval is justified in writing and that a process change brings it forward.
No. A workplace exposure limit is defined by what a person breathes. A monitoring exercise that produces only static results has not demonstrated compliance with a limit. Static sampling is genuinely useful for checking whether extraction is working, for mapping where a contaminant travels and for background comparison.
Accreditation is not a legal requirement under COSHH. It is evidential quality. It is what makes a result hard to argue with in an enforcement or civil claim setting. We tell you which methods were in scope and which were not.
Immediate interim measures go in on the day, which usually means restricting the task and upgrading respiratory protection with a documented face fit test behind it. The permanent fix is engineering. The extraction is examined and improved, then we re-monitor to prove the change worked. The result also feeds the risk assessment review and the health surveillance programme for the people affected.
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