Machine guarding and LOTO: When standards collide!
Who needs to worry about guards if lockout/tagout (LOTO) is in place? We all do, and we are reminded of the importance of both following a workplace fatality on July 13, 2025. A 19-year-old sanitation worker was tragically killed after falling into an industrial meat grinder they were cleaning. The grinder at the California food processing facility was then unexpectedly activated. Although coworkers heard cries for help and attempted to stop the machine, it was too late.
So, what happens when these standards seem to contradict each other? Can a machine be safely serviced without full lockout if guards are in place, OR does removing a guard automatically trigger the need for LOTO? Let’s explore the gray areas where these two critical safety systems meet, overlap, and sometimes collide—offering clarity, context, and practical guidance for navigating compliance without compromising worker protection.
Complimentary for the cause
The Machine Guarding under 29 CFR 1910 Subpart O and the Control of Hazardous Energy Sources (LOTO) standard at 29 CFR 1910.147 serve a very similar purpose of protecting workers. Fundamentally, they complement one another:
- Machine Guarding is a first line of defense, designed to prevent access to dangerous parts during normal operation (e.g., rollers, blades, gears, pinch points). Guards, barriers, and safety devices physically separate workers from moving parts and machine components.
- LOTO is a secondary control, used during servicing or maintenance (not normal operations) when guards may be removed or bypassed. It ensures that machines energy is isolated to prevent startup until work is complete.
Together, these standards form a layered safety approach with guards protecting workers during operations, and LOTO protecting them during maintenance. Since guards may be removed during servicing, the risk of injury is increased, which is where LOTO takes over to control energy and unexpected startup. Without proper LOTO, even a well-guarded machine can become deadly during maintenance or servicing tasks.
While both standards are intended to prevent injuries, they approach worker safety from different angles which can sometimes create confusion or conflict in implementation. The life of the young sanitation worker could have been saved if guards had been in place to prevent the fall into the grinder and proper LOTO had been performed to prevent unexpected start-up of the machine.
Combating the confusion
Both machine guarding and LOTO are essential safeguards designed to protect workers from machinery and energy source hazards, yet they operate under different OSHA standards with distinct expectations and applications. Additionally, confusion is created when dealing with routine vs. non-routine tasks. OSHA allows some minor servicing tasks to be performed without full LOTO if they are routine, repetitive, and integral to production, and if effective machine guarding is in place. As with the incident shared above, how would the employee have determined if cleaning the meat grinder was routine or non-routine — what qualifies as “routine?”
Routine operations are regular, recurring daily tasks with specific procedures. These may include inspections or daily adjustments to machines or equipment (e.g., frequent die changes or clearing regular jams. Non-routine operations are infrequent, unexpected, or new activities with unique risks. These often include emergency maintenance or process start-ups. Cleaning the meat grinder would likely be a routine activity; however, with the unique layout or size of the machinery, guarding alone was not sufficient.
Some maintenance does require removing guards, which exposes workers to hazards. If LOTO procedures aren’t strictly followed, there is a gap in protection. This can often result in the underuse LOTO while relying too heavily on guards when both should be used for full protection.
The confusion between machine guarding and LOTO requirements can be cleared up by:
- Clearly defining tasks that require machine guarding versus those covered by LOTO, and when both may be needed;
- Performing risk assessments to evaluate whether guarding alone is sufficient for specific machines or tasks;
- Documenting and communicating any exceptions to LOTO, including justification and alternative protective measures;
- Auditing programs and procedures regularly to identify and remediate gaps; and
- Training all supervisors and workers of the requirements in both standards.
Blurred by technology
Modern machines often include advanced guarding systems like light curtains or presence-sensing devices. While these tech marvels enhance safety, they can blur the lines between guarding and energy control. From an OSHA lens, these systems do not replace LOTO during servicing, which can add to the confusion for many trying to interpret compliance requirements. It’s imperative to understand that technology often helps protect workers from getting injured by machines, but they aren’t intended to necessarily control energy sources.
Clarity through training
Once employers have sifted through the collision confusion, workers must also be brought up to speed. Often, they have been trained in one standard but not the other, leading to inconsistent application. For example, operators may understand guarding but not LOTO procedures, especially in situations where operations and maintenance are handled by separate personnel.
Keys to remember: LOTO and machine guarding are not just essential, they are complimentary. When used together and correctly, they provide multi-layered approach to protection against serious injuries and fatalities.