What this is
What is an exposure result review?
What is an exposure result review?
A statistical review of a set of sampling results for a similar exposure group, judging the group's exposure profile against an occupational exposure limit rather than judging any single sample in isolation. It applies to any monitored agent, noise, dust, chemical, bioaerosol or heat, using the same statistical logic in every case.
How does it differ from a single sampling record?
A sampling record captures one result from one worker on one occasion. This review takes a set of those results spanning a period, calculates the geometric mean, variability and 95th percentile estimate, and asks what those figures say about the group's exposure as a whole, which a single result cannot answer.
When is an exposure result review completed?
After each sampling campaign, at the review interval set for the group, and after any trigger event such as a control change, a complaint, or a result that itself looks anomalous against the group's history.
Scope
When is an exposure result review required?
This review sits downstream of sampling, judging results already collected. Using it to decide whether sampling is needed at all, or to record a single result, belongs to a different template.
Use this template when
- A sampling campaign for a similar exposure group has produced enough results to review as a set
- The review interval for a group has been reached, regardless of whether a fresh campaign has run
- A control change, complaint or anomalous result has triggered an out-of-cycle review
- A linked sampling record or similar exposure group needs this review to exist against it
Do not use it for
- Similar Exposure Group Register, which defines and maintains the group itself, its tasks and membership, ahead of any statistical judgement about results
- Qualitative Exposure Assessment, which rates likely exposure from professional judgement before any sampling has occurred
- Personal Air Sampling Record or the equivalent single-sample record, which captures one result rather than judging the accumulated set
- Chemical Exposure Assessment or Biological Exposure Assessment, which assess the task and controls for an agent class before sampling
- Exposure Control Plan, which documents the controls chosen, distinct from this review's judgement of whether they are working
Compliance mapping
Which AIHA statistical guidance requirements does this satisfy?
Statistical review of exposure results is not itself a regulatory clause; it is the accepted professional method for satisfying the underlying duty to know whether an exposure limit is being met, and regulators expect the method to be defensible rather than prescribed.
| Clause | Requirement | Where it lands |
|---|---|---|
| AIHA Exposure Assessment Strategy | Characterise a similar exposure group's profile using the full data set, judged by percentile against the limit rather than by any single sample | Data set |
| AIHA Exposure Assessment Strategy | Use the 95th percentile as the decision statistic for exposure category, since it identifies the proportion of the group's exposure days that exceed the limit | Judgement |
| AIHA Exposure Assessment Strategy | Regroup workers whose sampling results are no longer statistically homogeneous with the similar exposure group they were assigned to | Judgement |
| OSHA 29 CFR 1910.1020 | Exposure records retained and made available, providing the period-based data set this review is built on | Header |
| OSHA 5(a)(1) | General Duty Clause obligation to act once exposure data shows a recognised hazard is not adequately controlled | Judgement |
| ISO 45001 cl.9.1.1 | Monitoring and measurement of the effectiveness of controls, evaluated against a defined method and criteria | Actions |
| ISO 45001 cl.10.2 | Nonconformity and corrective action, applied where monitoring shows control improvement is required | Actions |
What it does not cover
- Similar Exposure Group Register, which decides who belongs in the group being reviewed, a decision this review can prompt but does not itself make.
- Personal Air Sampling Record or the agent-specific sampling record, which is the underlying data this review consumes rather than produces.
- Qualitative Exposure Assessment, which is the judgement made before sampling exists, using task knowledge rather than results.
- Exposure Control Plan, which documents the control measures themselves, as distinct from this review's verdict on whether they are working.
- Health Surveillance Plan, which sets the ongoing medical surveillance programme that this review's exposure category can trigger a change to, but does not itself define.
Global
Exposure Result Review requirements by country
The duty to know whether an exposure limit is being met is close to universal; what differs is how prescriptive the regulator is about the statistical method and how the limit itself is set.
OSHA substance-specific permissible exposure limits; OSH Act 5(a)(1); AIHA exposure assessment strategy as accepted practice
OSHA sets the numerical limit for regulated substances; the statistical method for judging a group against it is professional guidance, not a prescribed procedure.
An inspector will accept a defensible statistical judgement against the applicable PEL; a review based on a single result or the mean alone is the likelier target of a citation.
Control of Substances Hazardous to Health Regulations 2002, regulation 10; HSE guidance on exposure monitoring
Monitoring is required where necessary to ensure a workplace exposure limit is not exceeded, with records kept for a defined period.
HSE guidance leans on the same statistical logic as AIHA's strategy, so a review built to that method broadly aligns with UK expectations.
ISO 45001 cl.9.1.1; AIHA and equivalent national occupational hygiene associations' statistical guidance
Monitoring and measurement of control effectiveness is a management system requirement, with the statistical method left to recognised professional practice.
Certification auditors look for a defined, consistently applied method rather than a specific formula, so the percentile-based approach travels across jurisdictions.
How to complete it
How to complete an exposure result review, step by step
The form calculates nothing the hygienist has not already decided to enter. The judgement calls are what turn a page of statistics into a defensible verdict about the group.
The 95th percentile estimate against the limit is the figure the exposure category should be built on. A geometric mean that looks comfortable can sit alongside a 95th percentile that is not, since a right-skewed data set is dominated by its low results in the mean and its rare high ones in the tail.
A geometric standard deviation above roughly three says the results are too spread out to represent one exposure population, likely because the group contains workers doing meaningfully different tasks. The fix is usually to regroup, not to explain the variability away as normal.
A control change recorded during the review period should show up in the following results if it worked. An improvement scored complete with no visible change in the 95th percentile or trend deserves a finding, not a pass.
Homogeneity is a precondition for the exposure category to mean anything. A group judged non-homogeneous but still scored against one category has produced a number describing an average of two exposure realities nobody actually experiences.
What auditors find
Most common exposure result review findings
Findings on exposure result reviews concentrate on the mean being treated as the verdict, and on groups whose composition has quietly drifted away from what the statistics assume.
| Finding | Clause | What fixes it |
|---|---|---|
| Exposure category judged from the arithmetic mean rather than the 95th percentile estimate. | AIHA Exposure Assessment Strategy | Base the category on the 95th percentile against the limit; record the mean only as context. |
| Geometric standard deviation above three not flagged as a homogeneity concern. | AIHA Exposure Assessment Strategy | Treat high variability as a trigger to review group composition, not just a statistic to record. |
| Group scored homogeneous despite a geometric standard deviation indicating otherwise. | AIHA Exposure Assessment Strategy | Cross-check the homogeneity judgement against the variability statistic before accepting either. |
| Control change recorded during the period with no check of whether results actually improved. | ISO 45001 cl.9.1.1 | Compare the trend and 95th percentile before and after the change, and record the result explicitly. |
| Review based on too few samples to support the statistic reported. | OSHA 29 CFR 1910.1020 | State the sample count and period spanned alongside the statistic, and flag where the set is too small to be reliable. |
| Workers not informed of the group result despite the field being scored yes. | OSHA 5(a)(1) | Require evidence of communication, such as a briefing record, before scoring this item complete. |
Case in point
Case in point: the group that averaged well and overexposed a quarter of its days
A packing line's similar exposure group was reviewed after a routine noise sampling campaign of twelve results. The arithmetic mean sat comfortably below the action value, the review was scored below action value, and monitoring frequency was reduced from quarterly to annual on the strength of it.
The geometric standard deviation, present on the same page, was above three. Recalculating the 95th percentile against the limit rather than reading the mean showed roughly a quarter of the group's likely exposure days sat above the action value, driven by a subset of workers on a different task rotation who were included in the same group. The reduced monitoring frequency had removed the only mechanism that would have caught this before the next scheduled review, eighteen months away.
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.
4 sections
- Reference
- HLT-007
- Archetype
- Review
- Record ID
- ERR-2026-000
- Scoring
- Exposure rating
- Direction
- High is bad
- Singleton
- No
- Basis
- AIHA statistical guidance
- Links
- Links Sampling records, SEG
- Tags
- Hygiene, Analysis
- Sections
- 4
- Fields
- 40
- Follow up fields
- 3
- Repeating sections
- 0
- Links out
- 4
Header
10 fieldsReview ID*
Auto sequence. Format ERR-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
Period Covered*
Agent*
SEG Reference
Links to HLT-001 Group Reference
One Result Means Little
Exposure varies enormously day to day. Judge a group on the spread of several results, not on the last one. A single low result does not prove control.
Data set
9 fieldsSamples In Data Set*
Period Spanned*
Samples Below Detection
Arithmetic Mean
Geometric Mean
Geometric Standard Deviation
Above three indicates high variability, which usually means the group is not homogeneous.
Highest Result*
95th Percentile Estimate
The number that matters. Most workers on most days should sit below the limit, not just the average.
Percent Of Limit At 95th Percentile*
Judgement
6 fieldsExposure Category*
Well controlled below ten percent, controlled below fifty, uncertain, or uncontrolled above the limit.
- Below action value4 pts
- Between action and limit1 pt
- Above limit value0 pts
Group Homogeneous*
- Yes3 pts
- Partly1 pt
- No0 pts
Regrouping Required*
- No3 pts
- Yes1 pt
Trend Over Time*
- Improving3 pts
- Stable2 pts
- Worsening0 pts
Controls Changed During Period*
Effect Of Control Change Visible
- Yes, improvement3 pts
- No change1 pt
- Worse0 pts
Actions
15 fieldsAdditional Sampling Required*
- No3 pts
- Yes1 pt
Control Improvement Required*
- No3 pts
- Yes0 pts
Control Plan ID
Links to HLT-008 Plan ID
Health Surveillance Change Required*
- No3 pts
- Yes1 pt
Monitoring Frequency Changed*
- No change3 pts
- Increased1 pt
- Reduced3 pts
Workers Informed Of Group Result*
- Yes3 pts
- No0 pts
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
Next Review Due*
Occupational Hygienist*
Signature*
Safety Lead*
Second Signature*
HLT-007 · record IDs look like ERR-2026-000 · Links Sampling records, SEG
Open in KnowellaRun it with agents
From a document you fill in to a programme that runs itself
The statistics in this review are only as good as the group they describe and the sampling record behind them. What actually fails is a group whose composition drifted, or a monitoring frequency reduced on a reading nobody re-checked.
Holds the exposure result review against the similar exposure group register and sampling records it depends on, and flags when group composition has drifted from what the statistics assume.
Tracks the control change this review is meant to verify, and links it to the review that should confirm whether it actually worked.
Watches for a review scored from the mean rather than the 95th percentile, and for a monitoring frequency reduced without a homogeneity check, before either reaches the record.
This template lives in KnowHealth — employee wellbeing. Exposure monitoring, health surveillance, case management and return to work.
Meet KnowHealth→Glossary
Exposure Result Review definitions and key terms
- Similar exposure group
- A set of workers sharing tasks, agents and exposure patterns closely enough that sampling results from any member can represent the whole group statistically.
- 95th percentile estimate
- The exposure level below which 95 percent of a group's exposure days are expected to fall, used as the decision statistic against the limit rather than the mean.
- Geometric standard deviation
- A measure of the spread of a log-normally distributed data set; a value above roughly three indicates the group's results are too variable to treat as one population.
- Action value
- An exposure level below the full occupational exposure limit that triggers additional control or surveillance action before the limit itself is reached.
- Homogeneous group
- A similar exposure group whose members' actual exposure varies only by chance rather than by systematic differences in task, area or method.
FAQ
Frequently asked questions about exposure result review
Why does the 95th percentile matter more than the average?+
The average is pulled toward the low results that dominate a typical sampling set and understates the group's worst days. The 95th percentile answers the question that matters for control: on a bad day, is a worker in this group likely to be overexposed.
What should trigger a review outside the normal interval?+
A control change intended to affect exposure, a complaint, an anomalous result, or evidence the group's composition or tasks have changed. Waiting for the scheduled interval when one has already occurred lets a known problem run unaddressed.
How many samples are enough to review a group statistically?+
Enough to estimate variability with reasonable confidence, which in practice means more than a handful. A review built on very few results should say so and treat its statistic as provisional.
What does a high geometric standard deviation actually mean for the group?+
That the spread of results is too wide to represent one exposure population reliably. Above roughly three, the group likely contains workers with meaningfully different tasks, and the response is usually to split it rather than accept the number as normal variability.
Should monitoring frequency be reduced on the strength of one good review?+
Only where the 95th percentile, not just the mean, supports it, and only where the group is confirmed homogeneous. A mean-based reduction removes the mechanism most likely to catch a group whose tail exposure was never actually low.
Does this review replace the underlying sampling records?+
No. It sits on top of them, judging the set as a whole. The individual records remain the evidence; this review is the interpretation, and both need to exist for the judgement to be checkable later.
Keep going
Related templates and programmes
Industries this is written for
Programmes this belongs to
Used together in Occupational Health Surveillance
Similar Exposure Group Register
Groups workers who share the same tasks, agents and exposure patterns
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
More in Exposure Monitoring
Similar Exposure Group Register
Groups workers who share the same tasks, agents and exposure patterns
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
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 — A Strategy for Assessing and Managing Occupational Exposures (exposure assessment strategy)
- OSHA 29 CFR 1910.1020 — Access to employee exposure and medical records
- OSHA Section 5(a)(1), General Duty Clause
- ISO 45001:2018 clauses 9.1.1 and 10.2
This page is general guidance, not legal advice. Confirm requirements with your jurisdiction’s regulator.