What this is
What is a similar exposure group?
What is a similar exposure group?
A similar exposure group is a set of workers who share the same task, the same agent and a genuinely similar exposure pattern, defined so that a sample or judgement taken from one member can be treated as representative of the whole group rather than of one person.
Why group workers instead of assessing everyone individually?
Sampling every worker individually is rarely affordable and rarely necessary if the exposure genuinely is shared. Grouping is what makes an exposure monitoring programme practical at all, but the saving only holds if the grouping is actually defensible, which is why the basis for grouping is recorded rather than assumed.
Who maintains the register?
The occupational hygienist, built once when the programme starts and reviewed at least yearly, and whenever a group is added, changed or retired. The register is master data other exposure records depend on, so its currency matters beyond its own review cycle.
Scope
When is a similar exposure group register required?
This register defines who belongs to which exposure group. Using it to judge exposure, to record an actual sample, or to track a health outcome puts that content in the wrong record and leaves the register itself thin.
Use this template when
- An exposure monitoring programme is being set up and groups need to be defined before any judgement or sampling begins
- A new task, area, agent or shift pattern has been introduced that changes who is exposed to what
- An existing group's membership, task mix or controls have changed enough to question whether it is still one group
- The yearly review is due, or a worker has been identified who does not currently sit in any group
- A qualitative assessment or sampling plan needs a defined group to be judged or sampled against
Do not use it for
- Qualitative Exposure Assessment, which judges the exposure of a group this register has already defined, rather than defining it
- Personal Air Sampling Record, which records an actual sample taken from one worker's breathing zone
- Noise Survey, which measures noise levels across an area rather than defining who shares an exposure pattern
- Area Monitoring Record, which records fixed-point sampling in a location rather than grouping people
- Health Surveillance Plan, which is the downstream health monitoring a group's exposure rating may indicate, not the grouping itself
Compliance mapping
Which AIHA Exposure Assessment Strategies requirements does this satisfy?
AIHA's exposure assessment strategy treats the similar exposure group as the foundational unit the rest of the programme is built on, and ISO 45001 expects the hazard identification and consultation behind that grouping to be genuine rather than assumed.
| Clause | Requirement | Where it lands |
|---|---|---|
| AIHA Exposure Assessment Strategies | Workers grouped only where exposure is genuinely homogeneous, with the basis for grouping recorded and defensible | Groups |
| ISO 45001 cl.6.1.2.1 | Hazard identification proactive and ongoing, covering every worker rather than only those already grouped | Register health |
| ISO 45001 cl.5.4 | Consultation and participation of workers in characterising how a task and its exposure are actually performed | Groups |
| ISO 45001 cl.9.1.1 | Monitoring and measurement determines whether a group is genuinely characterised, not assumed to be | Groups |
| ISO 45001 cl.7.5.3 | Control of documented information, including scheduled review, applied to the register as master data | Header |
| ISO 45001 cl.8.1.2 | Elimination and reduction of risk following the hierarchy of controls where a group's monitoring or action indicates it is needed | Register health |
What it does not cover
- Qualitative Exposure Assessment, which rates the likely exposure of a group this register has defined, and needs the group to already exist to mean anything.
- Personal Air Sampling Record, which records an actual measured sample from a worker's breathing zone rather than defining who the sample represents.
- Noise Survey, which measures noise levels across areas rather than establishing which workers share an exposure pattern.
- Area Monitoring Record, which records fixed-point sampling at a location, not the grouping of people by shared exposure.
- Health Surveillance Plan, which is the health outcome monitoring a poorly controlled group's rating may indicate, not the group definition itself.
Global
Similar Exposure Group Register requirements by country
No jurisdiction names the similar exposure group in law, but the concept underpins how monitoring obligations are actually discharged wherever sampling every worker individually is impractical.
AIHA Exposure Assessment Strategies; OSHA standard-specific monitoring requirements
OSHA standards for specific agents require exposure to be characterised, and AIHA's strategy is the accepted method for doing so at a group rather than individual level.
A monitoring programme sampling by group needs the grouping documented and defensible, because an inspector can ask why one worker's result was treated as representative of others.
HSE guidance on similar exposure groups and representative sampling
HSE guidance accepts representative sampling of similar exposure groups as a practical route to compliance with COSHH and noise regulations.
The grouping rationale is what an inspector examines when a sampling result is challenged, not the sample alone.
ISO 45001
Hazard identification must cover the whole workforce, and any grouping used to make monitoring practical must still be traceable to a defined, consistently applied methodology.
Certification auditors will ask how groups were formed and whether anyone falls outside all of them, since coverage gaps are a direct hazard identification failure.
How to complete it
How to complete a similar exposure group register, step by step
The register looks complete once every worker has a row in some group. Whether it is actually defensible depends on judgement calls the form prompts for but cannot make on its own.
Same task and area is the strongest basis for grouping and same job title alone is the weakest, and the form scores them accordingly. A group formed from a title should be treated as provisional until the actual tasks and areas within it have been checked for a shared pattern.
Exposure variability within a group measures how well the grouping actually holds. A group recorded as high variability and left unchanged is a group whose sample results will never mean the same thing twice, because they describe different members' realities each time.
Six to ten samples per group is the usual minimum to characterise exposure with any confidence, and a group marked characterised on fewer should be treated as partly characterised regardless of what the field says, because the sampling has not yet reached the point of being representative.
Workers not in any group have no exposure assessment at all, and that count is the register's own admission of a coverage gap. Leaving it non-zero without an action attached is leaving a known gap undocumented as a decision.
What auditors find
Most common similar exposure group register findings
The register usually exists and every worker appears accounted for; findings concern whether the grouping underneath is actually defensible.
| Finding | Clause | What fixes it |
|---|---|---|
| Groups formed on job title alone with no task or area rationale recorded. | AIHA Exposure Assessment Strategies | Redefine the basis for grouping against actual task and area, and record the reasoning, not just the title. |
| Exposure variability within a group marked high with no split or sub-grouping raised. | AIHA Exposure Assessment Strategies | Split a group into sub-groups once variability is high enough that one sample cannot represent it. |
| Workers not in any group left at a non-zero count with no action raised against it. | ISO 45001 cl.6.1.2.1 | Raise an action for every worker outside a group, with an owner and a date, not just a count on the register. |
| Group marked characterised with fewer than the recommended minimum samples taken. | ISO 45001 cl.9.1.1 | Reserve the characterised status for groups meeting the sample count criterion; otherwise mark it partly characterised. |
| Register review overdue against the stated interval, or unreviewed after a known layout or process change. | ISO 45001 cl.7.5.3 | Link the register review to management of change so a layout or process change raises it automatically. |
| Monitoring frequency not set for a group with an uncertain or uncontrolled exposure rating. | ISO 45001 cl.8.1.2 | Require a monitoring frequency before a group with an unfavourable rating can be closed off as reviewed. |
Case in point
Case in point: the group that was two groups
A meat processing site registered one similar exposure group for boning hall staff under the job title boner, covering two different lines. One line used a fixed cutting station with local exhaust ventilation; the other used a mobile station with none, added eighteen months earlier for a new product run. The register recorded same job title only as the basis for grouping, and variability was left at low without a specific check.
Samples from three workers on the fixed line came back well controlled, and the group's rating was set accordingly for all boning hall staff. A later audit sampled two workers on the mobile line and found results near the exposure limit, a result the register had no way to distinguish because both lines had been treated as one group from the start.
The template
The template, field by field
The form exactly as it installs. Every field, option, score and conditional rule is editable, and the links to other templates come with it.
3 sections
- Reference
- HLT-001
- Archetype
- Register
- Record ID
- SEG-2026-000
- Scoring
- Not scored
- Direction
- n/a
- Singleton
- No
- Basis
- AIHA Exposure Assessment Strategies
- Links
- Links Worker, Job
- Tags
- Hygiene, Master data
- Sections
- 3
- Fields
- 36
- Follow up fields
- 3
- Repeating sections
- 1
- Links out
- 2
Header
10 fieldsRegister ID*
Auto sequence. Format SEG-2026-000.
The record's own ID. Other templates point at this value.
Status*
Drives who this goes to next.
- Planned2 pts
- In progress2 pts
- Complete3 pts
- Deferred0 pts
- Open0 pts
- Closed3 pts
- Overdue0 pts
Date and Time*
Completed By*
Site*
Site ID*
Format SITE-000.
Links to FDN-001 Site ID
Group People, Not Jobs
A similar exposure group is a set of workers whose exposure is genuinely alike. Get the grouping wrong and every sample you take represents nobody.
Last Reviewed*
Reviewed By*
Next Review Due*
Groups
Repeats15 fieldsGroup Reference*
Group Name*
Agent*
Noise, dust, ammonia, cleaning chemical, cold, vibration or bioaerosol.
Area*
Tasks Included*
Workers In Group*
Basis For Grouping*
Same task and area is strongest. Same job title alone is the weakest and most common mistake.
- Same task and area4 pts
- Same task, different areas2 pts
- Same area, different tasks1 pt
- Same job title only0 pts
Exposure Variability Within Group*
- Low3 pts
- Moderate1 pt
- High0 pts
Shift Patterns Consistent*
- Yes3 pts
- Mostly2 pts
- No0 pts
Samples Taken To Date
Samples Required
Six to ten samples per group is the usual minimum to characterise exposure with any confidence.
Group Characterised*
- Yes3 pts
- Partly1 pt
- No0 pts
Highest Result To Date
Exposure Rating
- Well controlled, under 10 percent4 pts
- Controlled, under 50 percent3 pts
- Uncertain1 pt
- Uncontrolled0 pts
Monitoring Frequency Set*
- Yes3 pts
- No0 pts
Register health
11 fieldsGroups Defined*
Groups Fully Characterised*
Workers Not In Any Group*
Anybody not in a group has no exposure assessment at all.
Action Required*
Raise the action record, then enter its reference here.
- No2 pts
- Yes0 pts
Priority
- High0 pts
- Medium1 pt
- Low3 pts
CAPA ID
Format CAPA-2026-00000.
Links to FDN-014 CAPA ID
Action Owner
Occupational Hygienist*
Signature*
Safety Lead*
Second Signature*
HLT-001 · record IDs look like SEG-2026-000 · Links Worker, Job
Open in KnowellaRun it with agents
From a document you fill in to a programme that runs itself
The register is master data other exposure records lean on. What fails is keeping it current as tasks and layouts change underneath it.
Holds the register against the workforce and flags workers who fall outside every defined group as a coverage gap.
Links a group's unfavourable rating or high variability to a risk assessment and tracks the resulting action to a verified close.
Cross-checks task assignments and rotation against group membership, so a worker moved onto a different task is flagged before the register goes stale.
Watches layout, equipment and shift-pattern changes elsewhere in the record set that should trigger a group review, and raises it rather than waiting for the yearly date.
This template lives in KnowHealth — employee wellbeing. Exposure monitoring, health surveillance, case management and return to work.
Meet KnowHealth→Glossary
Similar Exposure Group Register definitions and key terms
- Similar exposure group (SEG)
- A defined set of workers whose task, agent and exposure pattern are alike enough that one sample or judgement can represent the whole group.
- Basis for grouping
- The recorded reason a group was formed as it was, ranked from same task and area, the strongest basis, down to same job title alone, the weakest.
- Exposure variability
- How much members of a group actually differ in their exposure; high variability undermines the assumption that one sample represents everyone in the group.
- Group characterisation
- The state of having enough samples, usually six to ten, to describe a group's exposure with reasonable statistical confidence.
- Coverage gap
- A worker who does not sit in any defined similar exposure group and therefore has no exposure assessment at all, tracked directly by the register.
FAQ
Frequently asked questions about similar exposure group register
Why not just assess every worker individually?+
Individual sampling of every worker is rarely affordable and, where exposure genuinely is shared, unnecessary. Grouping is what makes a monitoring programme practical, but only when the group is actually homogeneous, which is why the basis for grouping is recorded rather than assumed.
What if workers with the same job title do different tasks?+
Then they should not be in the same group on that basis alone. Same job title only is the weakest basis for grouping the form recognises, and it is also the most common shortcut, because payroll and organisational data already sort people that way.
How many samples does a group need before it counts as characterised?+
Six to ten is the usual minimum to describe exposure with reasonable confidence. Fewer than that supports a provisional judgement, not a settled characterisation, and the register should reflect that distinction rather than rounding up.
What happens if I get the grouping wrong?+
Every sample taken afterwards represents the group as defined, not the workers as they actually are. A misgrouped register can look complete and fully sampled while missing the subset of workers whose exposure is actually different.
How often should the register be reviewed?+
At least yearly, and whenever a group's task, area, membership or controls change enough to question whether it is still one group. The yearly interval is a backstop; the change is the trigger that actually matters.
What does a worker not in any group mean in practice?+
That person has no exposure assessment behind them at all. The register counts this explicitly because it is the most direct measure of whether the monitoring programme actually covers the workforce.
Keep going
Related templates and programmes
Industries this is written for
Programmes this belongs to
Used together in Hearing Conservation
Qualitative Exposure Assessment
Rates likely exposure using professional judgement, task knowledge and existing data, before any sampling
Audiometric Test Record
Records a worker's hearing test results
Standard Threshold Shift Review
Reviews a detected hearing shift to decide whether it is work related and what to do
Hearing Protection Fit Check
Checks that a worker's hearing protection actually fits and gives the attenuation assumed
Noise Survey
Maps noise levels across an area to identify where protection and controls are needed
Hazard Communication Training
Covers chemical labels, safety data sheets and what the hazard symbols mean
More in Exposure Monitoring
Qualitative Exposure Assessment
Rates likely exposure using professional judgement, task knowledge and existing data, before any sampling
Personal Air Sampling Record
Records a sample taken from a worker's breathing zone over a shift
Area Monitoring Record
Records fixed point sampling in a work area rather than on a person
Noise Dosimetry Record
Records a worker's noise exposure over a full shift using a personal dosimeter
Chemical Exposure Assessment
Assesses exposure to a specific chemical across the tasks where it is used
Exposure Result Review
Reviews sampling results statistically across a group, rather than judging single samples
Written and reviewed by
Siddarth Singh
Founder & Chief Executive Officer, Knowella
Certified Safety Professional and industrial and systems engineer with more than a decade inside food supply chain, freight and manufacturing operations. This page was written against the current text of the standards it cites, not against secondary summaries of them.
- Certified Safety Professional (CSP), Board of Certified Safety Professionals
- MBA, University of Chicago Booth School of Business
- MS and BS, The Ohio State University, Industrial and Systems Engineering
- Six Sigma Black Belt
Sources and last review. Reviewed 16 August 2026 against:
- AIHA Exposure Assessment Strategies (A Strategy for Assessing and Managing Occupational Exposures)
- ISO 45001:2018 clauses 6.1.2, 5.4, 9.1.1 and 7.5.3
- HSE guidance on similar exposure groups and representative sampling
This page is general guidance, not legal advice. Confirm requirements with your jurisdiction’s regulator.