What triggers a health surveillance obligation
Under the model WHS Regulations (Schedule 14 and regulation 42), health surveillance is triggered by exposure to listed hazardous substances or when a risk assessment determines surveillance is necessary due to the nature or level of exposure. The obligation is role-specific — determined by the documented exposure profile in the IROJ, not by job title or department.
This means: two workers in the same department with different roles may have different surveillance obligations. A maintenance technician who enters the spray booth intermittently has a different isocyanate exposure profile to a production painter. Generic surveillance programs applied by department rather than role-level exposure profile are both legally insufficient and clinically inappropriate.
The IROJ as the surveillance trigger
The IROJ documents every significant hazard exposure for each role — noise level (dB LAeq), dust exposure (mg/m³), chemical agents, biological agents, vibration (m/s² A(8)), and shift structure. This is the source from which surveillance trigger criteria, frequency, and program design should be derived. OccuSpan reads the IROJ hazard profile for each role and generates the applicable surveillance schedule automatically.
The six core health surveillance programs
These are the most commonly required surveillance programs in Australian industry. Each entry covers the legal trigger, frequency, key clinical points, and the industries where the obligation most commonly applies.
Noise — audiometry
WHS Regulations Sch 14 · NOHSC:1007
Trigger
Exposure at or above 85 dB LAeq(8h) or peak 140 dB
Frequency
Baseline (pre-exposure or within 3 months of first exposure), then annually
Key points
- ›STS = 15 dB average shift at 2, 3, 4 kHz in either ear (age-corrected)
- ›STS triggers mandatory clinical review, investigation, and engineering controls review
- ›Pre-placement baseline audiogram is the reference — protects employer and worker
- ›Audiometry by trained technician under medical oversight
- ›State notification requirements vary — WA, QLD, NSW have STS reporting obligations
Common industries: Mining, construction, manufacturing, transport, aviation
Silica — spirometry + chest X-ray
WHS Regulations Sch 14 · State silica notification laws
Trigger
Exposure to respirable crystalline silica (RCS) at or above the WES (0.05 mg/m³ TWA)
Frequency
Baseline, then 2-yearly; escalated if exposure or clinical findings indicate
Key points
- ›Spirometry (FEV1, FVC, FEV1/FVC) follows ATS/ERS standards
- ›Chest X-ray graded by ILO pneumoconiosis classification
- ›Several states require regulator notification of silicosis diagnoses — SA, VIC, QLD, NSW, WA all have obligations
- ›Engineered stone ban (2024) — crystalline silica dust from other sources remains a current obligation
- ›Records retained for 30 years post-employment
Common industries: Construction, mining, quarrying, tunnel works, ceramics, foundries
Lead — blood lead level (BLL)
WHS Regulations Sch 14 · NOHSC:3017
Trigger
Exposure to inorganic lead at or above the WES; Schedule 14 trigger applies
Frequency
Baseline, then 3-monthly or 6-monthly depending on BLL trajectory
Key points
- ›Venous blood lead level is the primary biomarker
- ›Trigger levels: 15 µg/dL (biological exposure index) → enhanced monitoring; 30 µg/dL → mandatory removal from exposure
- ›Female workers of reproductive capacity have a lower removal threshold (20 µg/dL recommended)
- ›Records retained for 30 years
Common industries: Battery recycling, smelting, demolition of lead-painted structures, firing ranges, radiator repair
Biological agents — vaccination + monitoring
WHS Regulations · State public health orders · NHMRC immunisation guidelines
Trigger
Roles with documented exposure to biological hazards — blood-borne pathogens, respiratory infections, zoonoses
Frequency
Baseline (pre-exposure), then per vaccine/titre schedule or annually
Key points
- ›Healthcare workers: Hep B (titre confirmation), influenza (annual), COVID-19 (state-specific), TB screen (Mantoux or IGRA)
- ›Agricultural workers: Q fever (pre-vaccination screen required — do not vaccinate previously sensitised workers), leptospirosis
- ›Laboratory workers: role-specific biological risk assessment determines the program
- ›State public health orders may impose additional vaccination requirements (NSW, Vic, Qld for certain health worker categories)
Common industries: Healthcare, aged care, veterinary, agriculture, laboratory, abattoir
Isocyanates — lung function + skin
WHS Regulations Sch 14 · NOHSC guidance
Trigger
Exposure to diisocyanates (TDI, MDI, HDI) in spray painting, foam production, coatings
Frequency
Baseline, then 12-monthly; enhanced monitoring if sensitisation indicated
Key points
- ›Spirometry (reversibility testing) plus structured symptom questionnaire
- ›Skin sensitisation monitoring (patch test where indicated)
- ›Isocyanate sensitisation is permanent — once sensitised, continued exposure causes occupational asthma
- ›Removal from exposure is mandatory on confirmed sensitisation
Common industries: Automotive spray painting, polyurethane foam manufacturing, adhesives, construction coatings
Whole-body vibration (WBV) — musculoskeletal
WHS Regulations · ISO 2631-1
Trigger
Daily WBV exposure above action value (0.5 m/s² A(8)) — plant operators, heavy vehicle drivers
Frequency
Baseline musculoskeletal assessment, then 2-yearly or on symptom report
Key points
- ›WBV exposure calculated from vehicle vibration magnitude × daily exposure duration
- ›Low back, neck, and lower limb musculoskeletal symptoms are primary health outcomes
- ›Vibration white finger (HAVS) from hand-arm vibration (HAV) is a separate program (ISO 5349)
- ›Exposure records are part of the IROJ and must document daily A(8) values for each vehicle/role
Common industries: Mining, construction, agriculture, transport, forestry
Record retention — the obligations most employers get wrong
Health surveillance records are not clinical files in the ordinary sense — they carry statutory retention obligations that survive employment cessation and, in some cases, business closure. The baseline audiogram from a worker's first day must be retained for 30 years from their last day of work. In practice, most employers who have been managing surveillance manually have gaps.
| Record Type | Retention Period | Notes |
|---|---|---|
| Asbestos, silica, lead, Schedule 14 substances | 30 years after last entry or after employment ceases | Long-latency disease risk — records must survive business closure |
| General health surveillance (noise audiometry, spirometry for other exposures) | 30 years recommended (varies by state); minimum 7 years | Baseline audiogram is critical — loss of baseline invalidates STS detection |
| Biological monitoring (blood lead, urinary metabolites) | 30 years if Schedule 14 substance; 7 years otherwise | Records must be accessible to the worker on request at any time |
| Vaccination and titre records | 7 years minimum; longer if public health order specifies | Worker must receive copies — do not retain without providing access |
| Drug and alcohol test records (chain of custody) | 7 years minimum; scheme-specific for workers compensation | Full chain of custody documentation must be retained, not just outcomes |
Frequently asked questions
What triggers a health surveillance obligation under Australian WHS law?
Under the model WHS Regulations, health surveillance is required when a worker is exposed to a hazard listed in Schedule 14 (specific hazardous substances) or where an OHS risk assessment determines that surveillance is required due to exposure above a defined level. Common triggers in Australian industry include: noise above 85 dB LAeq(8h) or peak 140 dB (audiometry); respirable crystalline silica (spirometry and chest X-ray); hazardous chemicals and biological agents at specified exposure levels; and lead, asbestos, isocyanates, and other Schedule 14 substances. The surveillance obligation is role-specific — it is triggered by the documented exposure profile in the IROJ, not by job title or department.
How long must health surveillance records be kept in Australia?
Health surveillance records must be kept for the longer of: 30 years after the last entry for workers exposed to substances with a long-latency disease risk (asbestos, silica, lead, hazardous chemicals listed in Schedule 14); or 7 years after the record is made for general health surveillance. The employer must give a worker a copy of their surveillance records on request, and must retain records even after the worker has left employment. OccuSpan timestamps and stores all health surveillance records with automated retention policy enforcement.
What is a standard threshold shift (STS) in audiometry?
A standard threshold shift (STS) is a clinically significant change in hearing threshold detected on follow-up audiometry compared to baseline. In Australia, STS detection follows the NOHSC:1007 criteria — a 15 dB average shift at 2, 3, and 4 kHz in either ear, age-corrected. An STS triggers mandatory clinical review, investigation of causal exposure, review of noise controls, and — in some states — regulator notification. OccuSpan automatically calculates STS against baseline audiograms and flags workers requiring review.
Who can conduct health surveillance in Australia?
Health surveillance must be conducted by, or under the supervision of, a registered medical practitioner with appropriate OHS training. Audiometry may be conducted by a trained technician under medical oversight. Spirometry requires a trained technician following ATS/ERS standards, with medical interpretation. Biological monitoring must follow AS/NZS analytical standards. OccuSpan integrates with occupational health providers to manage scheduling, results ingestion, and clinical follow-up within the platform.
OccuSpan Health Surveillance
IROJ-driven surveillance schedules — automated
OccuSpan reads the IROJ hazard profile for each role and generates the applicable surveillance schedule — audiometry, spirometry, biological monitoring, vaccination. Results are stored with 30-year retention, STS is calculated automatically, and overdue surveillance is flagged before regulators ask.
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