ISO 3457:2003

Overview

ISO 3457:2003 - Earth-moving machinery - Guards - Definitions and requirements specifies principal terms and performance requirements for guards and other means of protecting personnel from mechanical, fluid and thermal hazards on earth‑moving machines (as defined in ISO 6165). The standard is intended for equipment used as the manufacturer designed it and applies to hazards encountered during normal operation and routine maintenance.

Key safety principles promoted:

• Eliminate hazards by design where feasible
• Guard against residual hazards if elimination is not possible
• Warn users when neither elimination nor guarding is feasible

Key topics and technical requirements

• Definitions: clear terminology for guard types - barrier guards, fenders, fan guards, thermal guards, hose guards and distance guarding.
• General requirements:
  • Guards must be durable, free of sharp edges, easily attachable, and accessible for routine maintenance (hinges, tethers, handholds if >20 kg).
  • Rigidity tests using a 125 mm disc: typical loading criteria are 250 N (touch), 500 N (lean/fall), and 2 000 N (step/platform).
• Barrier guards:
  • Safety distances measured from the nearest location a person could occupy; restricted-visibility guards (e.g., skid-steer side guards) limited to 40 mm × 80 mm openings or equivalent area.
• Fenders:
  • Required where wheels/tracks can throw material or cause operator contact/damage to critical displays - protection zone includes operator space envelope (ISO 3411).
• Fan guards:
  • Guarding required if fans are reachable from ground/platform; opening sizes and guard-to-fan distances are specified (e.g., ≤90 mm distance → max opening width 12 mm; up to 320 mm → max 32 mm).
• Thermal guards:
  • Required for painted or metallic surfaces exceeding 75 °C that are within hand reach of the operator.
• Hose guards:
  • Hoses with pressures >5 000 kPa or temperatures >60 °C within 1.0 m of the operator must be guarded; guards must stop/divert fluid spray.
• Distance guarding:
  • Safety distances and reach tables (for upward, over, around and through openings) govern allowable openings and minimum barriers (e.g., reach‑up safety height 2.5 m; minimum reach‑over barrier height 1.0 m).

Applications and who uses it

ISO 3457 is used by:

• OEMs and machine designers (to integrate compliant guards)
• Safety engineers and risk assessors (for hazard mitigation and verification)
• Maintenance planners and service technicians (to ensure safe access/maintenance)
• Certification bodies, fleet managers and regulators (to assess conformity and operator protection)

Practical uses include specifying guard materials and openings, designing fenders and fan screens, setting safe maintenance procedures, and selecting hose coverings for high‑pressure systems.

Related standards

Commonly used with:

• ISO 6165 (earth‑moving vocabulary)
• ISO 3411 (operator dimensions and space)
• ISO 2867 (access systems)
• ISO 6682 (zones of reach)
• ISO 9244 (safety signs)
• ISO 12508 (bluntness of edges)

Keywords: ISO 3457:2003, earth‑moving machinery, guards, barrier guards, fan guards, thermal guards, hose guards, distance guarding, operator safety, machine guarding standards.