Safeguarding Basics

Designing Safeguards

There are numerous variations and additional requirements to the information listed here, but this is a starting point to help you understand what your guarding will need to look like.

Perimeter & Point of Operation Guarding

The standards basically state that if you can reach it, it’s a problem. If you don’t need to access the hazardous area, install fixed guards. If you do need to access the area, install interlocked guards.

The basic requirement of a fixed guard is that it is a minimum of 1800mm high from the walking surface to the top of the guard, and a maximum of 150mm from the walking surface to the bottom of the guard. There are additional requirements based on the height of the hazard and the distance from the operator. These guidelines may not meet the additional requirements. With the guards in place, can you reach the hazard? If so, the additional requirements likely apply.

Safety Devices

If you do need to access a point in the hazardous area due to process requirements, safety devices can help you do so safely.

While the basic requirement of a safety device varies depending on the device chosen, they must also meet the requirements presented in ISO 13849. There are additional requirements if light curtains are used, such as the distance of the light curtain to the hazard, based on the stop time of the machine. Always ensure that all regulations are met when implementing a safeguarding solution.

Hydraulic, pneumatic, electric, gravity – what kind of interlock do I need?

You need to incorporate your safety control system isolation to control all sources of energy in the order of effectiveness stated by the hierarchy of safeguarding controls (see A and B type standards such as CSA Z432 or ISO 12100 or ANSI B11.0 for more info).

Remember that the standards don't tell you what to safeguard, only how to safeguard (with the exception of prescribed methods in the applicable C type standards such as the press and robotic standards). Essentially, the level of safeguarding performance must equal or exceed the level of risk faced as defined in the risk assessment. This is the primary document to establishing a safer work environment within the context of safeguarding of machinery.