GuardSmart 136 – Fixed Machine Guarding – Your First Line of Defense
Fixed Machine Guarding – Your First Line of Defense
In 2016, the Occupational Safety and Health Administration (OSHA) issued 2,451 violations for improper or missing machine guarding for its machine guard standard (1910.212).
According to OSHA, any machine part, function, or process which may cause injury must be safeguarded. When the operation of a machine or accidental contact with it can injure the operator or others in the vicinity, that hazard must be either controlled or eliminated.
Similar machine safeguarding standards exist in Canada under CSA Z432-16 regulations. More detailed, machine-specific guarding requirements and performance criteria for machine safeguarding can be found in the ANSI B11.19-2010 standards.
Fixed guarding or a physical barrier is your first line of defense against a mechanical accident and is the most effective means of protecting workers from dangerous pinch points around machinery. It is a means of physically preventing a worker from contacting dangerous areas unless it is physically removed.
There are several fixed guarding principals that should always be considered when designing and fitting guards:
Principals of Fixed Guarding
• The guard should be considered a permanent part of the machine.
• The guard must make access to all moving parts and nip points physically impossible.
• The guard should be installed as close to the machine part as possible (considering appropriate mesh size based on distance to hazard), be secure, tamper-resistant and durable.
• The guard must not impede the operation of the plant/facility and should be designed for the specific job and equipment.
• The guard itself must not create a new hazard or manual handling risk.
• The guard must ensure that no object will fall into the moving parts.
• The guard can only be removed with a tool (where regulations require).
• The guard must allow for safe lubrication and maintenance.
Effective fixed guards should provide total protection from the hazard – workers should not be able to reach around, under, through or over (AUTO) fixed guards. Properly designed, installed and maintained fixed guards offer the added advantages of low cost, compact design and high reliability.
A 36-year-old maintenance mechanic was working in a baking factory when he noticed that one of the belts on a transfer conveyor that moved cupcakes from the oven onto wrapping and boxing equipment was out of alignment. The worker reached beneath the machine to feel the tension on the belts and stuck his right hand into the conveyor belt’s drive shaft gearing, causing fracture injuries to his wrist. The guard that was supposed to prevent users from placing their hand into the drive shaft steering of the power transmission was found five feet from the location where the worker was injured.
As a general rule, power transmission apparatus, such as the power drives on conveyors, are best protected by fixed guards that completely enclose the danger areas.