A survey is a single event on a single day, and everything that can later be said about it depends on what was recorded while it was happening. This page describes how a survey is prepared, what occurs on site, how samples are identified and tracked, and what a useful set of deliverables contains. Interpretation of results and sampling statistics belong to separate stages.
An industrial hygiene survey is a defined fieldwork event carried out to gather information about workplace exposure conditions. It may involve observation, discussion, examination of work activities, review of available records and the collection of measurements or samples.
The survey should have an agreed purpose. A broad walkthrough may be intended to identify matters requiring further assessment, while a focused visit may examine a particular activity, workforce group or operating condition. The purpose determines what information needs to be collected and what the survey can reasonably deliver.
Interpretation of exposure results, statistical treatment and detailed comparison with occupational exposure criteria belong to separate stages and are not covered on this page.
Useful fieldwork begins with basic characterisation of the workplace. This establishes what the organisation does, which areas and activities are relevant, who may be involved and what conditions are expected during the visit.
Information requested in advance may include a site layout, process description, shift pattern, workforce structure, task schedule, material list, safety data sheets and relevant previous reports. The surveyor may also need details of access arrangements, induction requirements, personal protective equipment, photography restrictions and permits.
The purpose is not to create an exhaustive desktop study. It is to avoid arriving without enough context to recognise significant activities or collect the intended evidence. Advance information also helps identify whether the planned day is likely to represent the work being investigated.
Where several departments or contractors are involved, a named site coordinator can help ensure that the appropriate people, areas and records are available. However, operational information should also be checked with workers and supervisors who understand how tasks are performed in practice.
The fieldwork normally begins with confirmation of the scope and current operating conditions. The surveyor may check what work is scheduled, whether there have been changes, which areas are operating and whether any abnormal conditions are expected.
An opening discussion should resolve practical matters without replacing direct observation. Process descriptions, job titles and written procedures may not capture informal task variation, production interruptions, cleaning activities or differences between teams.
The walkthrough provides an overview of the workplace and helps relate individual tasks to their surroundings. The surveyor may observe sources, pathways, worker locations, task duration, work practices, enclosure, housekeeping, neighbouring activities and movements between areas. Notes should distinguish what was directly observed from what was reported by others.
The sequence may be adjusted as the day develops. A task may begin earlier than expected, equipment may become unavailable or a supposedly routine operation may not take place. Changes should be recorded so the final deliverables accurately describe the conditions represented.
Contemporaneous records are essential. Notes may include times, locations, tasks, materials, workers or groups represented, operating status, interruptions and observations relevant to the survey question.
Where instruments are used, records should identify the equipment, settings, checks and relevant timing information. Where samples are collected, each item requires a unique identifier linked to the field record. Detailed personal breathing-zone technique and individual monitoring methods are covered elsewhere.
Photographs, sketches and process diagrams may support the written record where site rules permit them. Images should be labelled and stored securely because they may reveal employees, client information, proprietary processes or restricted areas.
Discussions with workers can provide valuable context about task frequency, variation and unusual conditions. Statements should be recorded accurately without treating recollection as direct measurement. Personal medical information is generally outside the surveyor's role and should not be included unnecessarily in industrial hygiene field notes.
Chain of custody is the documented connection between an item collected in the workplace and the result later reported for that item. It helps demonstrate that samples were identified, handled and transferred in a controlled manner.
Each sample should have a unique reference that corresponds with the field record and laboratory submission information. Documentation commonly identifies the project, sample type, collection details, requested examination and relevant handling instructions.
Custody records should show transfer from the fieldworker to the laboratory or courier, as applicable. Packaging should be suitable for the sample and should reduce the risk of damage, leakage, loss or cross-contamination. Any required storage or transport conditions should be established before the fieldwork.
Chain of custody does not prove that the sample represents every possible workplace condition. It demonstrates traceability of the item that was collected. Representativeness depends on the survey design and the circumstances documented on the day.
Turnaround should be agreed in realistic terms. It may depend on the quantity and type of information collected, external laboratory schedules, quality checks, requests for clarification and the complexity of the report.
A rapid verbal update may sometimes be appropriate for significant field observations, but it should be clearly distinguished from a reviewed technical conclusion. Preliminary information can change when records are checked or laboratory results become available.
Typical deliverables may include a description of the survey purpose, areas visited, activities observed, people or groups represented, dates and times, methods used, field records, results received, photographs where appropriate and stated limitations. The report should also identify deviations from the planned scope.
A useful deliverable allows another competent reader to understand what occurred without relying on undocumented recollection. It should make clear what was assessed, what was not assessed and whether the planned activities were actually observed.
Advance information — layout, process description, shift pattern, task schedule, material list, previous reports — exists to avoid arriving without enough context to recognise significant activities or collect the intended evidence.
Process descriptions, job titles and written procedures may not capture informal task variation, production interruptions, cleaning activities or differences between teams.
Notes should distinguish what was directly observed from what was reported by others. The same distinction should survive into the final report.
A rapid verbal update may be appropriate for significant field observations, but it should be clearly distinguished from a reviewed technical conclusion that may change once records and results are checked.
A survey is not a permanent declaration about the workplace. It records evidence relating to the conditions encountered and the scope agreed. Activities that did not occur, areas that were inaccessible and changes from the expected work pattern should be documented as limitations. Chain of custody demonstrates traceability of the item that was collected; representativeness depends on the survey design and the circumstances documented on the day.
Interpretation of exposure results, statistical treatment and detailed comparison with occupational exposure criteria belong to separate stages and are not part of the survey event itself.
It is a structured inspection of relevant workplace areas and activities to identify exposure circumstances, gather context and determine whether focused assessment is needed.
The activities observed should match the survey purpose as closely as practicable. Where normal work does not occur, the difference should be documented as a limitation.
Workers can explain task variation, frequency, interruptions and practices that may not be apparent from procedures or a brief observation.
It is the documented traceability of a sample from collection and identification through transfer to the laboratory and reporting.
Turnaround depends on scope, laboratory schedules, data review and quality checking. The expected timescale should be agreed before the work begins.
It may discuss reported activities, but it should clearly distinguish them from work directly observed during the fieldwork.