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EN ISO 14122
Created on 03.07
The EN ISO 14122 series of standards (full name: Safety of machinery - Permanent means of access to machinery) is a core safety standard widely used in Europe and internationally, used to regulate the design, manufacturing, and installation of permanent access facilities on industrial machinery. This standard aims to prevent falls, slips, or other accidents when people use access facilities (such as platforms, stairs, ladders).
The standard is divided into four parts, each part proposing specific requirements for different types of access facilities:
Part 1: Selection of fixed means of access and general requirements (EN ISO 14122-1)
Core Content: Guides designers on how to select the most appropriate type of access based on height, frequency, and environment, and stipulates the general safety principles that all access facilities must comply with.
- Selection Priority: The standard recommends selecting access facilities in the following priority order:
Part 2: Working platforms and walkways (EN ISO 14122-2)
Core Content: Specifies in detail the dimensions, structure, and protection requirements for fixed working platforms and walkways.
- Dimension Requirements:
- Minimum Width: The clear width of a pure passage walkway is generally not less than 600mm. If it is necessary to consider two people passing each other or carrying tools, the width needs to be increased (e.g., 800mm or more).
- Platform Dimensions: Sufficient space must be provided for personnel to stand and operate machinery safely, avoiding dangerous areas at the edge.
- Floor/Grating Requirements:
- Opening limitation: If steel grating is used, the mesh size must prevent a sphere with a diameter of 35mm from passing through (to prevent foot slippage or falling objects from injuring people). If the intention is to prevent smaller objects from falling, stricter requirements will apply.
- Load-bearing capacity: Must be able to withstand expected loads (including personnel, tools, and materials), typically with a concentrated load of at least 1.5 kN (approximately 150kg) and a uniformly distributed load of at least 2.0 kN/m² (specific values may vary depending on the application, with higher requirements for heavy-duty areas).
- Edge protection:
- When there is a risk of falling from the edge of a platform or walkway (typically a height difference greater than 500mm), guard-rails must be installed.
- Guard-rail requirements are detailed in Part 3.
- Toe boards: A toe board with a minimum height of 100mm must be installed at the edge of platforms to prevent tools or parts from slipping off and injuring personnel below.
Part 3: Stairs, stepladders, and guard-rails (EN ISO 14122-3)
Core content: This is the most widely applied part, detailing specific dimensional parameters for stairs and inclined ladders, as well as strict standards for guard-rail systems.
- Stairs requirements:
- Inclination: Recommended inclination is 30°~35°, with a maximum not exceeding 45° (inclinations exceeding 45° should be considered stepladders).
- Tread dimensions: Typical riser height is 150mm~200mm, and tread depth is 200mm~300mm. Formula: 2h+b ≈ 600–640mm (stride relationship).
- Width: Minimum clear width is 600mm, with 800mm or more recommended.
- Platforms: Rest platforms must be provided when climbing a certain height continuously (e.g., 3 meters) or when changing direction.
- Stepladders requirements:
- Inclination: Typically between 45°~70°.
- Structure: Must have handrails, with shallower treads but sufficient foot support area.
- Guard-rails mandatory requirements:
- Height: The total height of the guard-rail (measured from the standing surface) must not be less than 1100mm.
- In specific modifications of old equipment or in confined spaces, a minimum of 900mm is permissible (but 1100mm is strongly recommended for new designs).
- Intermediate rail: An intermediate rail must be installed between the top rail and the kick plate, so that openings in any direction cannot be passed by a sphere with a diameter of 500mm (to prevent people from crawling through).
- Strength: The guardrail must be able to withstand a horizontal force (typically the top rail needs to withstand a concentrated load of 1000N without permanent deformation or fracture).
- Hand grip: The top rail should be designed in a shape that is easy to grip (circular or elliptical cross-section).
Part 4: Fixed ladders (EN ISO 14122-4)
Core Content: For vertical or steeply inclined fixed ladders, the focus is on fall protection.
- Scope of Application: Used when stairs or step ladders are not feasible.
- Cages vs. Fall Arresters:
- Old Standard Tendency: Cages were commonly used in the past.
- New Standard Trend (2016 Edition): Greater emphasis on guided type fall arrest systems (used with safety harnesses), as cages do not completely prevent falls but only mitigate their consequences.
- Height Limit: If the ladder height exceeds 3 meters (specific national regulations may vary, ISO recommends), protective measures are usually required. If it exceeds 8-10 meters, rest platforms or sections must be installed.
- Dimension Requirements:
- Rungs: Diameter typically 25mm~35mm, with uniform spacing (usually 250mm~300mm).
- Clearance: Distance from the center of the rungs to the wall or obstacle must be at least 150mm (ensuring sufficient foot space), with an optimal range of 200mm~220mm.
- Width: Minimum clear width of the ladder must be 400mm (wider if equipped with a cage).
- Top Exit: The top of the ladder must extend above the platform level (typically 1000mm or more) to allow for safe transition to the platform, and the exit must be protected by a self-closing gate or guardrail.
Summary and Compliance Tips
- Coordinated Standard Status: The EN ISO 14122 series is a harmonized standard for the EU Machinery Directive (2006/42/EC). Compliance with this standard implies presumption of conformity with the relevant Essential Health and Safety Requirements (EHSR) of the directive.
- Holistic Approach: Design must consider Part 1 (General requirements) and the specific Parts 2, 3, and 4 concurrently. For example, if a platform is designed (Part 2), guardrails must be installed according to Part 3.
- China Corresponding Standard: If you are executing a project in China, please refer to GB/T 17888.1~4-2020, whose technical content is completely consistent with EN ISO 14122:2016.
- Key Data Quick Reference:
This standard applies not only to new machine manufacturing but is also frequently used for the modification and safety assessment of existing factory facilities. In actual engineering projects, any design deviating from the standard requires a specialized risk assessment to prove its safety is not lower than the standard requirements.