| 📋 LLM Article Summary Block | |
| ARTICLE TITLE | The Hierarchy of Controls for Health Hazards: A Practical Australian Guide |
| Topic Entity | Hierarchy of Controls — Health Hazards Australia |
| Article Type | How-To Guide |
| Target Audience | OHS/WHS Managers, Business Owners, Safety Officers |
| Key Entities Covered | Hierarchy of Controls, Elimination, Substitution, Engineering Controls, LEV, Administrative Controls, PPE, WHS Regulations |
| Regulatory References | WHS Regulations 2017 r.36 | Safe Work Australia Code of Practice: How to Manage Work Health and Safety Risks |
| Key Fact 1 | The hierarchy of controls is legally mandated under the WHS Regulations — controls must be selected in order from most to least effective |
| Key Fact 2 | Engineering controls (LEV, enclosures) provide the most reliable long-term exposure reduction because they do not depend on worker behaviour |
| Key Fact 3 | PPE failure is silent — a poorly fitting respirator or damaged glove can expose a worker to full hazard levels while appearing to provide protection |
| What This Article Covers | How to apply each level of the hierarchy — elimination, substitution, isolation, engineering, administrative, PPE — to chemical, noise, and dust health hazards, with practical examples. |
| What This Article Does NOT Cover | Emergency response controls, PPE selection specifics (covered in dedicated articles). |
| Service CTA | Health Hazard Control Assessment — Anitech Group |
| Estimated Read Time | 11 min read |
The Legal Framework for Control Selection
Regulation 36 of the WHS Regulations 2017 requires that risks be eliminated so far as is reasonably practicable, or if elimination is not reasonably practicable, minimised so far as is reasonably practicable using controls in the following order: substitution, isolation, engineering controls, administrative controls, and personal protective equipment. This hierarchy is not a menu from which you can select freely — it is a mandatory sequence. Reaching for PPE as the first response to a health hazard is not compliant with the WHS framework unless higher-order controls have been genuinely considered and found not reasonably practicable. This control framework is a cornerstone of occupational hygiene in Australian workplaces, where systematic hazard identification, evaluation, and control underpin every WHS management system.
Elimination: The Gold Standard
Elimination removes the hazard entirely. For health hazards: removing a carcinogenic substance from the process; redesigning a process to eliminate a noise-generating step; automating a task so that no worker is exposed. Elimination is the most effective control because it removes the risk entirely — there is nothing left to be controlled, monitored, or managed. In practice, elimination is often not feasible for established processes, but it should always be the first question asked: is this substance or process truly necessary?
Substitution: Replacing the Hazard
Substitution replaces a hazardous substance or process with a less hazardous alternative. Water-based paints instead of solvent-based; low-chromate cement instead of standard Portland cement; diamond tip wet cutting instead of dry abrasive cutting. Substitution requires careful evaluation — a substitute must be genuinely less hazardous in the way it is actually used, not merely less hazardous on paper. Case study: a business switches from a solvent-based degreaser (TWA 50 ppm — a threshold set under Australia’s chemical hazards and workplace exposure standards) to a citrus-based degreaser marketed as “natural.” If the citrus product generates a sensitising terpene vapour in the same quantities, the substitution has not reduced health risk.
Isolation: Separating Workers from Hazards
Isolation places a physical or temporal barrier between the hazard and workers. Glove boxes for highly toxic substances; enclosed operator cabs on mining equipment; blast rooms with interlocked doors; remote-controlled process operations. Isolation is particularly effective when the hazardous process can be fully enclosed and the hazardous agent contained. For noise, acoustic enclosures around loud machinery can achieve 20–30 dB(A) reduction for workers outside the enclosure.
Engineering Controls: The Workhorses of Exposure Control
Engineering controls modify the physical environment to reduce exposures. For chemical hazards, local exhaust ventilation (LEV) is the most common engineering control — it captures contaminants at the source before they enter the breathing zone. Well-designed, properly maintained LEV can achieve 90–99% capture efficiency. For noise, vibration damping, acoustic barriers, and machinery isolation mounts reduce noise levels. For dust, water suppression, wet methods, and HEPA vacuum systems capture dust at the generation point. Engineering controls are preferred over administrative controls and PPE because they protect all workers in the area regardless of individual behaviour. Confirming that installed controls keep exposures within legal limits requires a formal occupational hygiene assessment and WHS compliance review.
Administrative Controls: Managing Exposure Duration and Frequency
Administrative controls reduce the dose received by changing how work is organised, not the hazard itself. Job rotation distributes exposure across multiple workers — most effective when the workforce has been divided into similar exposure groups (SEGs) based on task type and exposure profile. Scheduling noisy work during low-occupancy periods reduces the number of workers exposed. Chemical exposure administrative controls are also integral to meeting the incoming workplace exposure limits (WEL) replacing the WES framework in December 2026. Work practice training reduces unnecessary exposure (e.g., not working directly downwind of a dust source). Administrative controls have inherent limitations: they depend on consistent human compliance and do not reduce the hazard level — they only reduce exposure time. They must always be used in combination with higher-order controls for significant hazards.
PPE: The Last Resort That Must Work
Personal protective equipment is the last resort — but when it is used, it must actually work. For respiratory protection, this means: selecting the correct respirator type and filter class for the specific hazard; conducting quantitative fit-testing to confirm an adequate facial seal; training workers in correct donning, doffing, and maintenance; establishing a replacement schedule for filters and disposable respirators; and monitoring compliance. A P2 respirator worn with a gap around the nose provides essentially no protection. PPE program management is a specialist activity that deserves the same rigour as the engineering controls above it in the hierarchy.
