Why the Term "Inherent Requirements" Has Legal Teeth
The phrase is not an HR invention. Section 21A of the Disability Discrimination Act 1992 (Cth) creates a specific carve-out: an employer does not discriminate unlawfully if the reason for adverse action is that a person cannot perform the inherent requirements of the job, and the employer has considered whether reasonable adjustments could address that gap.
Two words carry most of the legal weight there: inherent and reasonable.
Inherentmeans a task that is fundamental to the job — not merely convenient, traditional, or preferred. A night-fill worker who regularly lifts 20 kg stock has an inherent physical demand. An office manager who occasionally assists with moving furniture does not — that task is incidental. The distinction matters enormously because courts have struck down employer decisions where the"inherent requirement" relied upon was actually a marginal task the employer had inflated in scope.
Reasonable adjustment under section 4 of the Act requires the employer to genuinely consider modifications to equipment, hours, duties, or the work environment before concluding that a candidate or worker cannot perform the role. Only when that consideration has occurred, and where the adjustment would impose unjustifiable hardship under section 11, can an adverse health-based decision stand.
What Goes Into a Documented IROJ
A defensible IROJ document is not a job description. It is a structured breakdown of functional demands at the task level — with quantification. The following components should be present for every operational role:
Physical demands table
Frequency categories (occasional, frequent, constant), load specifications in kilograms, postural requirements (sustained, repetitive), reach zones, and grip or pinch force where relevant.
Environmental conditions
Confined space entry, heights, heat or cold stress exposure, vibration (whole-body or hand-arm), noise exposure levels, shift pattern including nights and on-call.
Cognitive and psychological demands
Decision-making complexity, attention and vigilance requirements, communication demands, exposure to trauma or distress.
Regulatory requirements
Licensing conditions, statutory fitness standards (e.g., Austroads for commercial vehicle drivers, CASA for aviation medicals), or safety-critical designations under the model WHS Act 2011.
Personal protective equipment requirements
Respiratory protection that requires a baseline spirometry, hearing protection fit, or fall-arrest harness that has body weight or medical preconditions.
This document is created by the employer — ideally with input from supervisors, workplace health and safety representatives, and an occupational health clinician — before any candidate is assessed. It should be reviewed whenever the role changes materially, and at least every three years.
How the Clinical Assessment Is Structured
Once the IROJ document exists, the clinician's job is to assess capacity against it — not to conduct a generic health check.
A well-structured IROJ assessment follows a consistent sequence:
- 1
History and self-report
Targeted medical history relevant to the role demands — musculoskeletal, cardiovascular, neurological, mental health. Self-reported limitations and current treatment.
- 2
Physical examination
Systems examination matched to role demands. A heavy manual handling role warrants full spinal, upper limb, and lower limb assessment. A sedentary role with keyboard work warrants upper limb and cervical assessment. Not every examination needs to cover every system.
- 3
Functional capacity testing
Standardised lifting, carrying, and postural tolerance tests calibrated to the IROJ thresholds. The clinician is measuring whether the person can meet the documented demand — not a theoretical maximum.
- 4
Ancillary investigations
Audiometry, spirometry, vision, drug and alcohol screening where specified by the IROJ. The AS 4308:2023 standard governs urine drug screening procedures; AS 4760:2019 governs oral fluid testing.
- 5
Outcome and recommendation
Fit, fit with conditions, requires further investigation, or not fit for the specified role. The outcome statement should reference specific IROJ demands — not generic fitness categories.
The Intersection of Three Acts — and Why All Three Matter
IROJ assessments sit at the crossroads of three pieces of federal legislation. Missing any of them creates exposure.
| Legislation | Relevance to IROJ |
|---|---|
| Disability Discrimination Act 1992 (Cth) | Defines inherent requirements; requires reasonable adjustment consideration; provides the lawful basis for adverse health-based decisions. |
| Model WHS Act 2011 | Requires PCBU to ensure workers are not exposed to risk beyond what is reasonably practicable. A worker placed in a role whose demands exceed their capacity creates a WHS liability regardless of the DDA position. |
| Fair Work Act 2009 (Cth) | Governs adverse action claims. Dismissal or non-engagement based on a medical condition must be substantively and procedurally fair — including consideration of all alternatives before a final decision. |
| Privacy Act 1988 (Cth) — APPs | Health information is sensitive information under the Australian Privacy Principles. Collection must be for a stated purpose; disclosure to line managers requires consent; retention and destruction require policy. |
The practical implication: an employer can comply with the WHS Act by declining to place a worker in a hazardous role, yet still be liable under the DDA if the decision-making process was flawed. These statutes do not resolve each other — they coexist, and the IROJ framework is the mechanism that satisfies all three simultaneously.
The Five Errors That Invalidate an IROJ Assessment
Most legal challenges to IROJ-based decisions do not hinge on whether an assessment occurred — they hinge on whether it was done properly. These are the five errors that appear most frequently in complaints to the Australian Human Rights Commission and Fair Work Commission proceedings.
IROJ document does not exist or was created post-hoc
The assessment report references a job demands analysis that was drafted after the medical outcome was known. This is the single most common and most damaging error.
Demands are overstated to exclude a known candidate
An employer inflates the physical demands of a role — increasing the stated lifting weight from 15 kg to 30 kg — specifically to generate a "not fit" outcome. Courts have found this to constitute disability discrimination irrespective of the DDA carve-out.
No documented reasonable adjustment consideration
The outcome letter states "not suitable" with no evidence that the employer considered modifying equipment, roster patterns, or task allocation. This alone can convert a lawful health-based decision into a prima facie discrimination case.
Clinician not provided with the IROJ document
The assessing clinician conducts a generic pre-employment medical and provides a generic outcome — fit/unfit without reference to specific role demands. The employer then applies that outcome to an IROJ framework after the fact.
Health information disclosed without consent
The medical report — containing diagnosis, medication, and clinical findings — is shared with a line manager or HR business partner without the worker's explicit consent. This breaches Australian Privacy Principles 6 and 11 under the Privacy Act 1988.
When IROJ Assessments Apply Beyond Pre-Employment
Pre-employment is the most common context, but IROJ frameworks apply across the employment lifecycle wherever a health-based decision is being made.
Return to work after injury or illness. Before a worker returns to full duties — particularly after a musculoskeletal injury, cardiac event, or mental health episode — a fitness-for-work assessment must compare current capacity to the original IROJ. If the IROJ has not been maintained, the comparison cannot be made objectively.
Role changes and redeployment. When an employer proposes to redeploy a worker with a health condition to a different role, the new role requires its own IROJ assessment. A worker who cannot meet the demands of Role A may be entirely capable of meeting the demands of Role B — but only a documented comparison can confirm this.
Periodic fitness-for-work reviews. Safety-critical roles — crane operators, mine vehicle operators, commercial vehicle drivers — typically require periodic re-assessment against the same IROJ. The frequency is usually 12 to 24 months depending on age and health risk profile, with more frequent review triggered by a known health change.
In all of these contexts, the legal and clinical logic is identical: measure capacity, compare to a documented benchmark, consider adjustment, document the decision. The IROJ framework does not change — only the occasion for applying it does.
Frequently Asked Questions
What does IROJ stand for and what is its legal basis?
IROJ stands for Inherent Requirements of the Job. The term derives from section 21A of the Disability Discrimination Act 1992 (Cth), which permits an employer to take health-related action — including declining to employ a candidate — where a person cannot perform the inherent requirements of the role even with reasonable adjustments in place. Without a documented IROJ, any adverse decision based on a medical finding is legally indefensible.
Who should conduct an IROJ assessment — an employer, HR, or a clinician?
The IROJ document itself is developed collaboratively by the employer and the assessing clinician — the employer specifies the physical, cognitive, and environmental demands of the role; the clinician assesses the candidate against those demands. A pre-employment medical conducted without a formally documented IROJ is not legally defensible under the DDA 1992 because there is no objective benchmark to compare the candidate's capacity against.
Can an employer automatically reject a candidate based on an IROJ assessment outcome?
No. The DDA 1992 requires the employer to first consider whether reasonable adjustments could allow the person to meet the inherent requirements. Only where reasonable adjustment is not possible — or where it would impose an unjustifiable hardship as defined in section 11 of the Act — can an adverse decision be made. Skipping this step exposes employers to a discrimination complaint with the Australian Human Rights Commission.
How specific does an IROJ document need to be?
Very specific. A vague statement like "must be able to perform manual handling" will not withstand scrutiny. The document should specify frequency (e.g., lifting 25 kg from floor to waist height up to 40 times per shift), posture requirements (sustained kneeling for up to 15 minutes), environmental conditions (confined spaces, shift work including nights), cognitive demands, and any regulatory requirements such as safety-critical roles defined under the model WHS Act 2011.
What is the difference between a functional capacity evaluation and an IROJ assessment?
A functional capacity evaluation (FCE) measures what a person can do — it quantifies their physical and cognitive capacity. An IROJ assessment compares that measured capacity against the documented inherent requirements of a specific job. The FCE provides the clinical data; the IROJ provides the job-specific benchmark. You need both for a defensible pre-employment or fitness-for-work decision.
Are IROJ assessments required for all roles or only safety-critical ones?
There is no legislative requirement to conduct IROJ assessments for every role, but best practice and legal defensibility strongly favour doing so for roles with significant physical demands, safety-critical tasks, or where a health condition could create risk under the model WHS Act 2011. Industries including mining, construction, transport, emergency services, and health care routinely apply IROJ frameworks to all operational roles.