Lockout/Tagout Safety for Volumetric Concrete Mixers

Lockout/Tagout Safety for Volumetric Concrete Mixers

Regarding safety in the concrete industry, few protocols are as crucial as lockout/tagout (LOTO). For volumetric concrete mixer operators, understanding and adhering to LOTO procedures is vital in preventing serious injuries and fatalities. Unfortunately, Lock Out Tag Out is one of our industry's most overlooked safety procedures. The U.S. Occupational Safety and Health Administration (OSHA) has developed specific standards that regulate how to manage energy sources during equipment servicing and maintenance safely, and these are especially critical in environments where heavy machinery, such as volumetric mixers, is in use.

What is Lockout/Tagout?

Lockout/tagout is a safety procedure that ensures dangerous machines are properly shut off and cannot be restarted or actuated until maintenance or servicing is complete. This is particularly important for equipment using hazardous energy sources, such as electricity, hydraulic pressure, or mechanical components like volumetric mixers.

OSHA's standard 29 CFR 1910.147 outlines the requirements for controlling hazardous energy during the service and maintenance of machinery. The goal is to prevent unexpected startup or release of stored energy, which could cause severe injury or death.

Lockout/Tagout and Volumetric Mixers: Why It’s Critical

The mixing auger is the most significant danger in the context of volumetric concrete mixers. This component is powerful enough to cause serious harm if inadvertently activated during cleaning and maintenance. If the machine is not properly locked out, the auger can entangle tools, clothing, hair, or even limbs, leading to catastrophic injuries. Additional hazards include chains and sprockets, electrical components, mechanical pinch points, and the hydraulic system. Each one of these may have a singular or combined hazard. If you are working on a particular electrical component, the voltage and amperage hazard may be the only hazard, while if you are working on the hydraulic lift cylinder, the hydraulic system pressures, as well as the mechanical pinch points, can be combined together and need to be addressed.

Implementing effective LOTO procedures and the appropriate training for volumetric mixers protects employees from these risks and ensures that the machinery is in a safe state before maintenance begins. These procedures should be reviewed for each business as the needs, setup and equipment may vary. One example that we previously implemented was the inclusion of a hydraulic shutoff valve for the auger. This mechanically locked out the ability of the auger to turn. We felt this was necessary for chipping and cleaning procedures.

OSHA Regulations and Volumetric Mixers

OSHA’s lockout/tagout standard (29 CFR 1910.147) applies to any machinery requiring servicing where hazardous energy is present. For volumetric mixers, OSHA mandates that workers be trained to: 

1. Identify Energy Sources: Understand all potential energy sources within the equipment, from electrical power to hydraulic pressure in the mixer.
2. Follow Energy Control Procedures: Before any maintenance, all energy sources must be isolated, and the machine should be locked out using appropriate devices such as padlocks.
3. Tag the Equipment: A visible tag should be placed on the mixer, alerting others that the equipment is being serviced and cannot be turned on.
4. Verify Isolation: Ensure that all energy sources have been properly isolated and the machine cannot restart. This includes actuating the machine’s controls to confirm isolation. 

Neglecting these steps can have fatal consequences. According to OSHA, failure to comply with LOTO standards is one of the most frequently cited violations across industries, including the construction and concrete sectors.

Common Best Practices for LOTO with Volumetric Mixers 

• Detailed Training: Ensure all personnel who work with volumetric mixers, including operators and maintenance staff, are thoroughly trained in LOTO procedures. Training should cover both general LOTO protocols and the specific hazards associated with the equipment. While training takes place on an ongoing basis, the most critical training is conducted during on-boarding of a new employee. They should be properly trained and be able to demonstrate the LOTO procedure in a hands-on manner.
• Use of Standardized Devices: Lockout devices such as padlocks, tags, and hasps should be standardized across your operation. This ensures that everyone can easily recognize and apply the correct lockout tools during servicing. In our previous experience, we used similar hasps and locks along with door tags or steering wheel covers to indicate the machine was out of service.
• Routine Inspections: Regularly audit your LOTO practices to ensure compliance with OSHA standards. Inspections should confirm that energy isolation devices are in place, procedures are followed, and all personnel remain current on their LOTO training. At Custom-Crete, we conducted annual audits and periodic training. While we had multiple LOTO safety meetings per year, one meeting was dedicated solely to confirming everyone was up to date with hands-on training. 

• Visual Verification: After locking out and tagging the mixer, ensure a visual check is completed. This helps confirm that the machine has been fully de-energized before any hands-on work begins.
• Communication: Establish clear communication channels to prevent unauthorized personnel from accessing locked-out equipment. This is especially important when multiple workers are servicing a machine, as they should each apply their own lock and tag to ensure their personal safety.

The Dangers of Non-Compliance: Real-World Examples

Unfortunately, many companies fail to adequately enforce lockout/tagout procedures, and this neglect can have devastating consequences. A recent investigation by The Wall Street Journal found that lockout/tagout violations have been linked to numerous worker deaths, often due to companies cutting corners on safety protocols and employee complacency. This highlights the ongoing importance of LOTO training, especially for those working with complex and hazardous machinery like volumetric mixers.

In one reported case, a worker was killed after becoming entangled in a machine that had not been properly locked out. The Wall Street Journal article points to these types of incidents as avoidable with the correct use of LOTO systems. The article goes on to say that failing to respect LOTO protocols puts workers directly in harm's way, with deadly consequences when machinery is accidentally activated during maintenance.

Post-Lockout/Tagout Procedures: Ensuring Safety After Maintenance

After completing maintenance or repairs, it’s important to ensure that the machine is returned to a safe, operational state. This process involves: 

1. Removing the Locks: Only authorized personnel should remove lockout devices after confirming that the area is clear and all maintenance tasks are complete.
2. Restoring Energy Safely: Gradually restore energy sources to the machine, ensuring that no one is in harm’s way.
3. Testing the Equipment: Run the machine through a test cycle to ensure that everything is functioning properly before returning it to full service.

Conclusion

Lockout/tagout procedures are essential in ensuring worker safety, particularly when servicing volumetric concrete mixers. The moving components, mixing auger, and hydraulic system present real dangers if proper precautions aren’t taken. By adhering to OSHA standards and incorporating LOTO best practices, businesses can significantly reduce the risk of injury and fatalities on the job. We also encourage producers to speak with their mixer manufacturer to find out specific needs for their mixer make and model.  

At Concrete Business Solutions, we’re committed to helping companies in the volumetric concrete industry implement effective safety protocols, including LOTO training and compliance programs. Ensure that your team understands the importance of LOTO and prevent avoidable accidents this keeps your workplace safe and efficient.

For more information on how we can help your business with volumetric mixer safety training and best practices, visit our website at www.concretebs.com.

References: 

1. OSHA Standard 29 CFR 1910.147 – *The Control of Hazardous Energy (Lockout/Tagout)*.
2. The Wall Street Journal, *Machine Lockout Rules Are Being Violated—and It’s Killing Workers*,  wsj.com (https://www.wsj.com/business/machine-lockout-rules-are-being-violated-its-killing-workers-ac50059f). .