Requirements for Fixed Stairs, Guardrails and Platforms

Guardrail height: which rule applies where?

In metal and machinery factories, falls often happen in places not regarded as “work at height”: on the maintenance platform above a press, on the steep ladder up to the roof of a paint booth, at the open edge of a mezzanine used for materials or at the top hatch of a tank. What these places have in common is that they are permanently installed and therefore no one ever measures them again. There is no single source of dimensions for guardrail height and the other elements of a guardrail; which rule applies depends on the type of area:

Annex 1, item 40 of the Regulation on Health and Safety Measures in Workplace Buildings and Annexes requires suitable guardrails on all open sides of raised walkways, platforms or working landings and in places with a risk of falling from height, and that the height, strength and openings of guardrails and their intermediate elements are such as to eliminate the risk of falling. Item 41 requires stairs to be of adequate width and slope and enclosed by guardrails; item 27 requires mezzanine floors to withstand the weight of the machinery, materials and people on them. Annex I, item 2.16 of the Regulation on Health and Safety Requirements for the Use of Work Equipment also requires workers to be able to reach the places where they carry out production, maintenance and adjustment safely and to work there safely.

For new machinery, under the Machinery Safety Regulation (2023/1230/EU), most of whose provisions enter into force on 20.01.2027, the manufacturer must resolve access means against the risk of falling in the design; in practice this means platforms and stairs complying with TS EN ISO 14122. For bringing old machines into compliance, see our article on bringing old machines without CE marking into line with minimum requirements.

Platform guardrails: dimensions checked in inspections

TS EN ISO 14122-3, which governs permanent means of access to machinery, requires guardrails on platform and walkway edges where the fall height exceeds 500 mm. A guardrail consists of three elements: a handrail at the top, an intermediate rail in the middle and a toe board at the base. On site, the intermediate rail is sometimes known by names such as “middle rail” or knee rail; whatever it is called, its function is to stop a body sliding under the handrail from passing through the gap.

Do not mix up the two columns. On a factory’s permanent maintenance platform, the 1-metre value given for construction sites falls short; the target for a machine platform is 1100 mm. On a construction site, on the other hand, the toe board must be 15 cm. Specify in writing in the risk assessment which source you take as the basis in your own facility.

In addition to the dimensions, the following points are also checked:

• Does the guardrail flex and do its posts wobble when shaken by hand? Are there cracks in the welds or missing bolts?
• Is there a gap at the platform edge, between the guardrail and the machine body or wall, through which a person could pass?
• Is the toe board continuous, or has it been cut for a cable tray or pipe penetration?
• Do the openings in grating floors allow small parts to fall; is anyone working underneath?
• At the platform entry point where the stairs end, is the opening in the guardrail protected by a self-closing gate?

Mezzanines and storage platforms

Mezzanines are used in factories both as storage and as work areas, and their weakest point is the loading edge. This edge, where pallets are set down by forklift, is often “closed” with a chain or a removable pipe. Instead, solutions in which the edge is never fully open at any moment, such as a double pallet gate that closes automatically on one side when the other opens, should be preferred.

The following are also checked on a mezzanine:

• Is the load capacity (kg/m²) clearly displayed at the mezzanine entrance, and is the stored load below this value?
• Are the stairwell and openings in the floor surrounded by guardrails?
• Are racks leaning against the guardrail; is material hanging over the top of it?
• Is there protection against falling material on walkways under the mezzanine?

For checking racking systems themselves, see our article on industrial racking safety.

Fixed stair dimensions

The dimensions of inclined fixed stairs used for access to machinery are set in TS EN ISO 14122-3, and those of escape stairs in buildings in Art. 41 of the Regulation on the Fire Protection of Buildings. The values in the Regulation for escape stairs are:

• The step rise may not be more than 175 mm and the tread depth may not be less than 250 mm.
• The headroom above the steps is at least 210 cm, and the level difference between landings at most 300 cm.
• At each floor level, a landing is provided at intervals of no more than 17 and no fewer than 4 steps; the landing may not be narrower than the stair width.
• Steps are made of slip-resistant material, and there is a wall, guardrail or handrail on both sides of the stairs.

The same logic applies to stairs leading up to machine platforms: the rise and depth of the steps should not change from top to bottom of a flight, step nosings should be slip-resistant and visible, and the stairs should be possible to hold onto on at least one side. In a staircase you have built yourself, the point where step dimensions change is the point where tripping is most likely. For the general rules on escape routes, read our article on escape routes and emergency exit doors.

Caged ladders and fixed vertical ladders

Vertical ladders leading to tank tops, roofs, crane runways and silo hatches are the means of access with the greatest fall height. Under TS EN ISO 14122-4, fall protection is required on fixed vertical ladders when the climbing height exceeds 3 metres: this protection may be a back cage (caged ladder) or a guided fall arrester sliding on a rigid line. The standard also provides for the distance between rungs to be within 225–300 mm and equal, and for the clear width between stiles to be 400–600 mm. The starting height of the cage, the spacing of hoops and verticals and rest platforms on long ladders are also defined in the standard; when buying, ask the manufacturer to document compliance with these dimensions.

Common deficiencies on site are:

• The cage ends at the top exit of the ladder and there is nothing to hold onto when stepping across to the platform.
• The guardrail opening at the platform exit has been left open; a person stepping off the ladder steps towards the void.
• The ladder is too close to the wall or tank behind it; the foot cannot rest fully on the rung.
• There is no locked gate at the bottom of the ladder; unauthorised persons or children (on open sites) can climb it.

For the compatibility and inspection of full-body harnesses on ladders with guided fall arresters, see our article on full-body harnesses, and for anchor and line systems, anchor points and lifelines.

Preparing for inspection: measurement and records

Checking guardrails and stairs should be a fixed part of the OHS specialist’s site round. The arrangement we recommend is:

1. Enter all platforms, mezzanines, fixed stairs and vertical ladders in the facility on a numbered list and a sketch plan.
2. For each one, measure and record the guardrail height, intermediate rail opening and toe board with a tape measure; photograph them.
3. Rank nonconformities by risk level; remedy those with a direct risk of falling, such as open edges and missing guardrails, without delay.
4. Link guardrails removed for maintenance to the permit-to-work system.
5. Update the list at least once a year and whenever there is a change in the facility.

For the general framework of the site round, see our article on the OHS site round checklist, and for sector-specific risks, our metal and machinery sector page. We carry out the measurement of platforms and stairs and the follow-up of nonconformities within our OHS specialist service.

Frequently Asked Questions

How many cm should a platform guardrail be in a factory?

TS EN ISO 14122-3, which governs permanent access to machinery, provides for the handrail on permanent platforms to be at least 1100 mm, with at least one intermediate rail and a toe board at least 100 mm high. For temporary edge protection on construction sites, the values of 1 m and 15 cm in Annex 5 of the OHS Regulation for Construction Work apply.

From what height is a guardrail required?

Under TS EN ISO 14122-3, guardrails are required on machine platform and walkway edges where the fall height exceeds 500 mm. The Regulation on Workplace Buildings and Annexes also requires suitable guardrails wherever there is a risk of falling from height.

When is a cage mandatory on a fixed vertical ladder?

Under TS EN ISO 14122-4, fall protection is required on fixed vertical ladders with a climbing height of more than 3 metres; this may be a back cage or a guided fall arrester system.

Can a guardrail be removed during maintenance?

It can, but the removal must be linked to a permit to work, the area must be cordoned off with tape and, if necessary, work must be done with a harness. Before the job is finished, it is checked and recorded that the guardrail has been refitted.