Machinery Guarding: Safety Moment#31

The process for machine isolation should be part of an organization’s comprehensive safety management system. The process should include:

• identifying and assessing risk
• implementing suitable risk controls and reviewing them
• developing safe work method statements
• consulting with workers during the development of (and changes to) the safe work method
• ensuring only trained and competent workers undertake the task.

Safety Devices

Electrical interlocks or other devices tied into the equipment’s control circuit are mounted on access points and are configured to stop equipment operations when opened. These access points should also incorporate hardware to comply with the OSHA lockout/Tagout regulation 1910.147. The lockout/Tagout hardware allows the operator or maintenance person to lock the equipment in the stopped state while performing duties in the hazardous area.

Light curtain systems may be used alone or in conjunction with other guarding systems. The light curtain projects a field or beams of light between two points and when the field is broken-at any point, the light curtain system interrupts the circuit it is wired into. These can be used in areas where an operator must interact with operating equipment to prevent movement of the equipment while the operator works a hazardous area.

Pressure-sensitive mat for an operator of the laser cutter Pressure-sensitive mats that are wired into the equipment’s control system can be placed in hazardous areas and be set to stop the equipment if stepped on. These devices can be used alone or in conjunction with other guarding devices, usually at operator interaction points.