Guidance on fall risk vs. heights

Working at Height Good Practice Advocacy

Ask that the GPG provide data and analysis on the consequences of falls by listing specific hazards and acceptable controls. Managing risk means understanding the hazard and the risk exposure or interactions with the hazard.

Gravity is just energy, and when you elevate people or material, you create a store of that energy as potential energy. A fall is just the conversion of that potential energy into kinetic energy, until it is released during an attenuated arrest or hard impact.

This can all be expressed mathematically, and understanding this and the potential forces it can produce will help people understand that fall protection is not a connection problem; it is an engineering one that requires high levels of performance.

Once we understand, we can see all the places where compliance is visible, but performance is not. Without performance, you do not have effective controls and have failed a legislative duty.

By expressing this in guidance, and referencing it when it is applicable (anchor systems, fall clearances, attenuation in lanyards and lifelines), industry might understand that while a harness is a convenient control, it is often underperforming.

Research on fall outcomes at different heights shows likely harm severity, but it makes one thing clear: if you test it, all bets are off for any single incident, because context matters far more than predictive physics. Luck is not a control.

WorkSafe has access to injury data, that could be used to inform some thresholds of risk. For example, the contradiction between the 6kN maximum force a person is permitted to take during an arrested fall (for 100 kg, this is ~600 mm) and the geometry guidance in the building code and for scaffolding that only requires protections over 1m or permits falls up to 1 m. This contrasts with access to some machines and buildings, or the use of ladders that are unprotected at much larger distances.

These are genuine inconsistencies that are codified or accepted as unresolvable, but the physics is the same in all cases once the potential energy becomes kinetic.

The guidance should not shy away from these contradictions, but provide acceptance within the contexts of each. For example, the 6kN is only realised under free-fall conditions, so slopes or interrupted falls would result in less. A force that is conformally attenuated, such as a 4m fall into a soft landing system, reduces force through distance slowing down and the local damage that force can supply as pressure, through redistribution of the landing surface.

There are answers, and if you would like to see them in guidance, let me be your voice and sign the petition to show support so I can advocate on your behalf.