GuardSmart 139 – Hidden Dangers of Machine Fixed Guarding
Fixed Guarding is an excellent way to protect workers from the hazards of pinch-points and rotating parts. Properly designed and installed fixed guards can provide comprehensive protection by utilizing barriers to isolate workers from potential hazards, but be aware the following dangers of fixed machine guarding, which are often overlooked:
• Fixed guards do not meet the “safe mounting distance” requirements. In accordance with ANSI B11.19-2010 – Performance Criteria for Safeguarding, guards must be positioned far enough away from the danger zone to ensure workers cannot make contact with the hazard.
• Inadequate fasteners are used in securing the guards. Not only must the fasteners be strong enough for the application, but some industries require a “Tool to Remove” in order to prevent unauthorized removal, bypassing or adjustment of fixed guards.
• Guarding that is structurally inadequate or made from materials that could deteriorate due to temperature extremes, ultraviolet radiation, chemicals, vibration, etc. Guarding material selection should be based on risk assessment findings and include consideration of operational conditions.
• Guarding restricts visibility behind the guard. Workers should be able to see what is behind the guard.
• Equipment is modified or relocated rendering the guarding inadequate or non-compliant.
• Guards are removed and not replaced during maintenance, installation or repair. Proper lockout procedures should require replacement of fixed guards prior to removing locks. On-going inspections will verify continued compliance.
Overlooking these fixed guarding hidden dangers puts workers at risk of injury.
A properly conducted Machine Guarding Risk Assessment can provide the tools and rationality needed to develop and install solutions that satisfy safety, quality and productivity needs.
An experienced worker, with over 6 years on the job, had bent down alongside a conveyor to plug a weigh scale in when she felt herself being “propelled violently backwards”. A subsequent investigation would reveal that her hair became entangled in the drive shaft underneath the conveyor. The employee had part of her thumb amputated. She lost part of her hair and suffered from considerable pain, which led to a surgeon having to shave part of the bone in her head to relieve her suffering. The incident was caused because the employer failed to reinstall safety guarding to the bottom of the conveyor after it had been relocated.
Helpful Links & References
Occupational Safety & Health Administration | Chapter 1 – Basics of Machine Safeguarding | https://www.osha.gov/Publications/Mach_SafeGuard/chapt1.html
Alberta Ministry of Labour | Best Practices on Conveyor Safety | https://work.alberta.ca/documents/WHS-PUB_bp008.pdf
American National Standards Institute | ANSI B11.19-2010 | Performance Requirements of Safeguarding | https://webstore.ansi.org/RecordDetail.aspx?sku=ANSI+B11.19-2010
November 2014 Edmonton Journal, Value Drug Mart fined $80,000 for safety violation. Retrieved from: http://edmontonjournal.com/news/local-news/value-drug-mart-fined-80000-for-safety-violation