Standards / Agriculture

Safety of Agricultural Machinery

EN ISO 4254 is the multi-part European standard for the safety of agricultural machinery. Its general part sets requirements common to all such machines — guarding, access, controls, stability and the information the manufacturer must supply — and further parts address specific machine types including balers, harvesters, sprayers and loaders.

Scope

EN ISO 4254 applies to self-propelled, mounted, semi-mounted and trailed agricultural machinery. The general part covers guarding of moving parts including power take-off drive shafts, safe access to operating and maintenance positions, control layout and marking, stability, and the operator information required.

Exclusions & Related Standards

• Roll-over protective structures are assessed separately under ISO 3471.
• Tractor cab protection against hazardous substances falls under EN 15695.
• Protective clothing for pesticide operators falls under EN ISO 27065.
• Chainsaw protective clothing falls under EN 381.

Key Requirements & Marking

Power take-off drive shafts must be guarded along their full length, with the guard tube prevented from rotating with the shaft by restraint devices at both ends, and with the tractor and implement shields overlapping the tube so no length of shaft is exposed. Other requirements cover fixed and interlocked guards on moving parts, safe access and working positions, control identification, and the marking and instructions supplied with the machine.

The guard tube must not turn with the shaft, which is what the restraint chains at each end prevent.

Testing Overview

Assessment covers the strength, retention and coverage of guards, verification that guarded areas cannot be reached during normal operation, stability testing appropriate to the machine type, functional checks of controls and stopping devices, and confirmation that the required markings and operator instructions are provided.

Selection Guide

When buying or hiring, confirm that all guarding is present and undamaged before the machine is accepted, that the operator manual is supplied, and that the machine is matched to the tractor it will be used with. Replacement guard components are inexpensive relative to the machine, so a missing guard is never a reason to accept a machine into service.

Inspection, Care and Maintenance

• Check power take-off guarding before every use, including that the guard tube turns freely on the shaft and that both restraint chains are attached
• Replace damaged or seized guard tubes rather than removing them, since a removed guard is rarely refitted
• Confirm fixed guards over drives, chains and belts are in place and secure after any maintenance
• Keep the operator manual with the machine, as guarding and stopping arrangements differ between models
• Withdraw machines with missing guards from use rather than operating them with care

A seized or cracked guard tube gets removed rather than replaced, and the machine then runs unguarded for years.