Lockout/Tagout – Alternative Methods (Risk Assessment) W. Jon Wallace, CSP, MBA Workplace Group O: E:
Compressed Springs
Is this an energy isolating device?
Human Safety Blocks?
Equipment-Specific Lockout Procedures: (c)(4)
What about tasks you perform routinely where the equipment must remain energized? Alternative Methods – Risk Assessment
A word about risk Risk: Severity X Frequency X Probability
Plastic Injection Molding Machine
Industrial Robot
Example of equipment-retrofit:
References for performing Risk Assessment: ANSI Z244.1: Control of Hazardous Energy - Lockout/Tagout and Alternative Methods. ANSI/RIA R15.06: Industrial Robots and Robot Systems - Safety Requirements. ANSI B11.19: 2010 Performance Requirements for Safeguarding OSHA CPL: : The Control of Hazardous Energy – Enforcement Policy and Inspection Procedures
Performing Risk Assessment: 1. Identify all tasks: Tasks where equipment must remain energized. 2. Identify Hazards: Electrical; gravity; chemical; pneumatic; etc. 3. Assess Potential Consequences: Worst case scenario (injury).
Performing Risk Assessment (Cont’d): 4. Assess potential exposure to hazards. 5. Assess probability of occurrence. 6. Evaluate the risk. 7. Achieve an acceptable level of risk.
Let’s Perform an Example: Employee changes tooling on robot once per shift. Existing interlock category: R2C
A Word about interlocks (per ANSI/RIA R15.06) : CategoryCircuit Performance R1Control Reliable R2AControl Reliable R2BSingle Channel with monitoring R2CSingle Channel R3ASingle Channel R3BSimple (Simple safety circuit) R4Simple (Simple safety circuit) How to determine interlock: Manufacturer and E&I folks. Increasing Sophistication
Back to our example: Employee changes tooling on robot once per shift. Existing interlock category: R2C TaskHazard(s)SeverityExposure (Frequency) AvoidanceProtective Measures Risk Reduction Required Changing tooling on robot. Struck by (moving robot). S2 (Serious injury) E1 (Infrequent) A2 (Not likely to move out of way) Interlock: R2C R2B LEGEND: Summary: Interlock needs to be upgraded from R2C to R2B.
Interlock requirement (ANSI/RIA R15.06) Remember: S2; E1; A2.
Putting it all together: Evaluate your lockout/tagout program. Implement upgrades as needed. Inventory tasks where equipment must remain energized. Perform risk assessment using ANSI Lockout and Robotic standards. Upgrade safeguards as needed.
Conclusion Question/Comments?