ISO 3691-4 Safety Standard Australia
AS/NZS ISO 3691-4 (current edition: 2023) is the safety standard governing driverless industrial trucks in Australia. It's the standard SafeWork inspectors will reference when evaluating an autonomous forklift deployment, the standard insurers will expect to see compliance evidence against, and the standard that defines what "safe" actually means for a robot operating alongside humans. This guide explains what's in it, in plain language.
What ISO 3691-4 Actually Covers
ISO 3691 is the umbrella standard for industrial truck safety. Part 4 is specifically about driverless trucks — AGVs, autonomous forklifts, autonomous tractors, and autonomous reach trucks. The standard defines:
- Hazard identification — the systematic process of identifying every way the truck could harm people or property
- Safety functions — the technical capabilities required (emergency stop, obstacle detection, speed limitation, operator-presence, etc.)
- Performance levels — using ISO 13849 functional safety, with most safety-rated functions required at PL d (Performance Level d)
- Verification requirements — how the manufacturer demonstrates compliance, and how the user verifies it
- Documentation — the manuals, training records, and evidence trail required
The Australian Adoption
Australia and New Zealand jointly adopted ISO 3691-4 as AS/NZS ISO 3691.4. SafeWork regulators in all states and territories reference this adoption when evaluating autonomous truck deployments. The standard is voluntary in the sense that it isn't directly cited in the WHS Act, but it's the de facto compliance pathway: a deployment that satisfies AS/NZS ISO 3691-4 satisfies the regulator's "reasonably practicable" test for plant safety. A deployment that doesn't reference the standard faces a much higher evidentiary burden.
How AS 2359 (Australian Lift Truck Standard) Relates
Many Australian operators ask how AS/NZS ISO 3691-4 relates to AS 2359 (Powered Industrial Trucks), the long-standing Australian lift truck standard. The relationship:
- AS 2359 series covers manual industrial trucks — design, performance, operation, and operator training. It's the standard most Australian forklift operators have been licensed under for decades.
- AS/NZS ISO 3691.4 specifically extends industrial truck requirements to driverless operation, addressing the additional hazards introduced when a powered truck has no operator.
- Both apply to a mixed fleet site — manual trucks under AS 2359 and autonomous trucks under AS/NZS ISO 3691.4.
- Safe Work Australia model WHS regulations 213-218 (powered mobile plant) cover both, with site-specific risk control obligations.
For an autonomous fleet deployment, the regulator expects evidence the operator has considered both standards: AS 2359 for the manual fleet (if any) and AS/NZS ISO 3691.4 for the autonomous fleet, plus the interaction between the two where they share operating space.
Required Safety Functions
| Safety Function | Performance Level | What It Means |
|---|---|---|
| Emergency stop | Cat 3 PL d | Truck reaches safe stop within defined distance when E-stop triggered |
| Pedestrian detection | Cat 3 PL d | Truck detects person in path and stops before collision |
| Obstacle detection | Cat 2 PL c minimum | Truck detects static and moving obstacles, reduces speed or stops |
| Speed limitation | Cat 2 PL c | Truck speed cannot exceed safe values for context (zone-based) |
| Battery isolation | Cat 1 PL b | Power can be safely isolated for maintenance |
| Warning signals | Cat 1 PL b | Audible/visual warnings communicate truck activity to bystanders |
The Risk Assessment Process
Step 1: Define the System
Document the truck, the environment, the operating zones, the people who interact with it, and the operating modes (auto, manual, maintenance). This sets the scope of the assessment.
Step 2: Identify Hazards
Walk through every operating scenario and identify every way harm could occur — collision, crush, electrical, fire, fall-from-load, ergonomic, etc.
Step 3: Estimate Risk
For each hazard, estimate severity (S1-S2), exposure (F1-F2), and possibility of avoidance (P1-P2). This generates a required performance level per ISO 13849-1.
Step 4: Implement Controls
Apply the hierarchy of controls: eliminate, substitute, engineer, administer, PPE. Engineering controls (the truck's safety functions) carry most of the load.
Step 5: Verify
Test that each safety function actually performs at its required PL. This requires functional safety verification, not just functional testing.
Step 6: Document & Maintain
Keep the risk assessment, verification reports, training records, and incident logs as live documents. Re-assess on any change to the system or environment.
What SafeWork Inspectors Look For
From observed inspections of autonomous forklift sites across Australia, regulators consistently focus on:
- The current risk assessment (signed, dated, owned by named person)
- Verification reports for safety-rated functions (not just commissioning reports)
- Training records for everyone who interacts with the truck (operators, supervisors, maintenance, even cleaners)
- Documented separation between manned and autonomous zones, where relevant
- Evidence the standard was applied, not just referenced (often missed)
- Incident log including near-misses, with corrective actions tracked to closure
Robots Now! ISO 3691-4 Compliance
Every autonomous forklift we deploy in Australia is supplied with:
- Manufacturer's compliance declaration against ISO 3691-4:2023
- Site-specific risk assessment template aligned with the standard
- Functional safety verification reports for each Cat 3 PL d function
- Training program template covering operators, supervisors, maintenance and visitors
- Annual verification scheme included in maintenance contracts