Machine Guarding — Compliance and Protection for UK Facilities

Why Machine Guarding Is a Legal Requirement

In the UK, the primary regulations governing machine guarding for employers are the Provision and Use of Work Equipment Regulations 1998 (PUWER). Regulation 11 of PUWER places a specific duty on employers to prevent access to dangerous parts of machinery, and sets out a hierarchy of measures — fixed enclosing guards first, then other guards or protection devices such as interlocks, then protection appliances such as jigs and push sticks, and finally the provision of information, instruction, training and supervision. Fixed and movable guards, of which welded steel mesh perimeter guarding is the most common form for larger machines and cells, sit at the top of that hierarchy. Machinery placed on the market must also comply with the Supply of Machinery (Safety) Regulations 2008, which implement the requirements historically associated with the Machinery Directive and require that machinery is supplied with appropriate guards. The HSE regularly enforces against employers where inadequate guarding has led to injury.

EN ISO 14120 — Fixed and Movable Guards

The specific harmonised standard covering the design and construction of fixed and movable guards is BS EN ISO 14120. It defines the general requirements for guards used to protect people from mechanical and other hazards, including the minimum distances that guard openings must sit from the hazard (so that a person cannot reach through the mesh and touch a moving part), material strength, resistance to impact, resistance to attempts to defeat the guard, and the fixings that must be used so the guard cannot easily be removed without a tool. When mesh aperture and standoff distance from the hazard are chosen together against the tables in EN ISO 13857 (safety distances to prevent upper limbs reaching danger zones), the resulting enclosure gives compliant protection against reach-through access. Rackstor UK Ltd machine guarding panels are designed against these standards, and every installation is documented with the panel specification and layout as-installed.

Fixed vs Interlocked Guards

A fixed guard is bolted in place and can only be removed with a tool — appropriate where access behind the guard is only required infrequently for maintenance. A movable guard, typically a hinged or sliding door in the perimeter fence, is used where operators need routine access into the guarded volume. Wherever a movable guard is used, it must be interlocked with the machine control system so that opening the guard removes power from the dangerous parts, and closing the guard alone does not restart them. Interlocks are typically mechanical safety switches, magnetic coded switches or non-contact RFID-coded switches wired back to a safety relay or safety PLC. The choice depends on the safety category required by the machine's risk assessment (per EN ISO 13849-1). Rackstor UK Ltd supplies the mesh guarding structure and door assemblies; interlock switches and the safety control system are normally provided by the machine builder or the site's control engineer.

Applications and Layout

Steel mesh machine guarding is used to enclose robotic welding cells, pick-and-place robots, automated guided vehicle (AGV) charging bays, palletisers, packaging lines, conveyors, presses, CNC machining centres and any automated production cell where operators must be prevented from reaching moving or dangerous parts. Layout usually follows the machine's working envelope with clearance around it, and includes access doors at points where the operator needs to load blanks, remove finished parts or reach in for planned maintenance. Cut-outs are made in the mesh where conveyors, pipework or cable trays pass through the perimeter, and those cut-outs are edged with cover strips so they do not present a laceration hazard.

Panels, Doors and Finish

Machine guarding panels are typically welded steel mesh (commonly 50 × 200 mm aperture, 4 mm wire) in a bolted tubular steel frame, with panel heights of 1.6 m, 2.0 m and 2.4 m as standard and widths in 500 mm increments up to around 2.0 m. Posts are Ω-profile or box-section steel bolted to the floor. Doors are supplied as hinged single or double leaves, or as sliding doors on floor tracks where floor space for a hinged sweep is not available. The standard finish is a two-tone polyester powder coat — safety yellow (RAL 1023) on the mesh panels and charcoal grey (RAL 7016) on the posts and doors — chosen to give high visibility of the guarded volume while blending the structure into the wider factory palette. Alternative colour schemes are available where a specific brand or facility colour is required.

Installation and Handover

Installation begins with a survey of the machine layout, cell footprint, floor condition, service routes into the cell and required door positions. From that survey the perimeter is drawn up and manufactured to size. On site, floor lines are set out and posts are drilled into the concrete slab, mesh panels are bolted between posts, and doors are hung and adjusted. Interlock switches are then fitted by the machine's control engineer, and the completed installation is checked against the layout drawing. Handover documentation includes the as-installed drawing, panel and hardware schedule, and confirmation that the guard structure is designed to EN ISO 14120. Where the machine is being brought into service, the site's authorised person completes the machine-level risk assessment and PUWER inspection incorporating the guard.

Free Survey and Quotation

Rackstor UK Ltd provides free machine guarding surveys and fixed-price quotations across the UK. Call 0800 654 6955 or use the enquiry form.

Frequently Asked Questions