Work-related health harm receives far less attention than injury, and it causes substantially more deaths. The reason is timing — an accident is immediate and attributable, while occupational disease appears years or decades after the exposure that caused it.
The major exposures
Respirable crystalline silica — from cutting, grinding and drilling concrete, stone, bricks and engineered stone. Causes silicosis, which is irreversible, and increases lung cancer risk. Engineered stone benchtop fabrication has produced serious cases internationally and here.
Asbestos — still present in a large proportion of buildings constructed before 2000. Remains the leading cause of work-related death in New Zealand, with a latency of decades.
Welding fume — classified as a carcinogen, with additional risks from specific metals such as manganese and hexavalent chromium from stainless steel.
Wood dust — particularly hardwood dust, associated with nasal cancer and respiratory disease.
Solvents and isocyanates — in spray painting, coatings and adhesives, causing occupational asthma and neurological effects.
Diesel exhaust — a carcinogen, relevant in workshops, warehouses and underground work.
Noise — causing permanent hearing loss, which is entirely preventable and extremely common.
Vibration — hand-arm vibration from power tools causing permanent circulatory and nerve damage.
Control follows the hierarchy
The failure mode across all of these is the same: reaching straight for personal protective equipment when higher controls were reasonably practicable.
- Eliminate — different material, different process, buy components pre-cut so the cutting happens under controlled conditions elsewhere.
- Substitute — lower-silica materials, water-based coatings, quieter equipment.
- Engineering controls — on-tool extraction, water suppression for cutting, local exhaust ventilation, enclosure of noisy plant, low-vibration tools.
- Administrative — job rotation, exclusion zones, scheduling noisy work when fewer people are present.
- PPE — last, and only effective if correctly selected, fitted and maintained.
On-tool extraction and water suppression for silica are well proven and comparatively cheap. A business relying on disposable masks for concrete cutting has chosen the weakest available control.
Respiratory protection needs fit testing
A tight-fitting respirator that does not seal provides substantially less protection than assumed. Fit testing is required to confirm the specific model fits the specific person, and facial hair at the seal prevents an effective seal regardless of the equipment.
This is one of the most commonly missed requirements in New Zealand workplaces.
Exposure monitoring and health monitoring
Where workers may be exposed to substances hazardous to health, exposure monitoring may be required to determine actual levels, and health monitoring to detect early effects.
Health monitoring is not a general medical check. It targets the specific effect of the specific exposure — lung function for respiratory hazards, audiometry for noise, biological monitoring for certain substances.
Baseline monitoring at the start of employment matters, because without it later deterioration cannot be attributed.
Noise specifically
Exposure standards apply to noise, and where they are exceeded the duty is to reduce exposure so far as reasonably practicable rather than simply to issue hearing protection.
Practical measures that work: buying quieter equipment at procurement, enclosing or isolating noisy plant, maintenance (worn equipment is louder), and separating noisy operations in space or time.
Audiometric testing establishes a baseline and detects loss early enough to act.
Asbestos
Any building constructed before 2000 should be assumed to potentially contain asbestos until surveyed. A management plan is required where asbestos is present, and a survey is required before refurbishment or demolition work that may disturb it.
Removal above thresholds requires a licensed removalist, and certain removal work is notifiable to WorkSafe before it starts.
Why this gets neglected
The harm is invisible for years, the person affected may have left the business, and nothing appears to be going wrong. That is precisely the argument for treating it systematically rather than reactively.
WorkSafe publishes exposure standards, guidance on silica, asbestos, noise, welding fume and health monitoring, free at worksafe.govt.nz. The exposure standards document is the reference point for whether a control is adequate.
General information only, not legal advice.
