Health & Safety Guidance Notes : Machine Safety

1. Introduction
   • Legislation relating to machinery safety has evolved quickly over recent years.  From the general requirement to 'securely fence all dangerous parts of machinery' (e.g. Factories Act 1961), there are now a number of more extensive duties and responsibilities specified:
     • Health and Safety at Work etc. Act 1974: employers must ensure the safety of machinery, but so also must designers, manufacturers and suppliers.
     • Supply of Machinery (Safety) Regulations 1992: this introduced an explicit requirement for manufacturers and suppliers to assess the risks arising during the lifetime of a machine.
     • Provision and Use of Work Equipment Regulations 1998.
     • Management of Health and Safety at Work Regulations 1999.
     • These latter two lay down much more specifically the areas of machine safety that employers should be addressing.
2. Safety Issues
   • The general principles of machinery safety can be placed in a hierarchy as follows:
     • Identification of hazard(s)
     • Elimination or reduction of hazard(s) by design
     • Use of safeguards
     • Use of safe working practices.
   • Machinery hazards can include the following:
     • (A) MECHANICAL
       • From the movement of machinery parts (i.e. rotary, sliding or reciprocating)
       • Entanglement or catching (e.g. hair, clothing, jewellery)
       • Friction and abrasion
       • Cutting
       • Shearing
       • Stabbing and puncture
       • Impact
       • Crushing
       • Drawing in
       • Compressed air/high pressure fluid.
     • (B) NON-MECHANICAL
       • Access problems (e.g. obstructions/projections)
       • Handling and lifting
       • Electrical
       • Chemical
       • Fire and explosion
       • Noise and vibration
       • Temperature
       • Radiation

Miscellaneous related safety considerations include suitability of controls (including start, stop and emergency stop controls); type and effectiveness of braking systems; feeding devices; work holding devices; lubrication; stability; lighting; safety colours and symbols; access.  The British Standard (BS5304) 'Safety of Machinery' provides ergonomic data that establishes safe reach distances for use with guards.

The selection of safeguards will be influenced by whether access to the danger area is required during normal operation:

Guard Designs include:

(A) Fixed guard - no moving parts; robust; tools needed to remove; preferably captive fastenings e.g. fixed enclosing guard or fixed distance guard.

(B) Interlocking guard - movable part(s); movement is interconnected with the power/control system so that until the guard is closed the power is interrupted OR guard stops locked closed until risk of injury has passed; may be of mechanical, electrical, hydraulic or pneumatic type; need to minimise risk of 'fail to danger' and mustn't be readily overridden.

(C) Automatic guard - moved into position automatically by the machine; physically removes from the danger area any part of a person exposed to danger.

(D) Adjustable guard (e.g. woodworking machines) - may be fixed or movable but the adjustment remains fixed during operation; need regular maintenance of the fixing arrangements.

(E) Self-adjusting guard - may be fixed or movable and adjusts to accommodate the passage of the material.

(F) False table - where power operated feed table carries material to the operating point of the machine.

Safe working practices (in addition to the provision of efficient and effective guarding) should include:

• Ensuring safe access
• A good standard of housekeeping
• Provision/display of suitable warning notices
• Procedures for emergency isolation and dissipation
• Adequate degree of supervision (which generally Increases with risk, up to written procedures and permit to-work systems)
• Adequate information, instruction and training for operators and supervisors
• Effective maintenance (& keeping of records) by competent persons.  NB Safe working procedures for maintenance and cleaning are required.  This will include effective isolation or locking off, not just switching off).
• Enhancing machine safety by ensuring good lighting/temperature control/ventilation.

Guidance Notes - Printable version