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Best Practices in Wood Waste Recycling Click here for printable PDF version Identifying Safety Risks in Wood Processing Material: Wood Waste Issue: The equipment used to process wood waste (rolling stock, conveyors, screens, hogs/shredders, etc.) poses a variety of safety issues that require ongoing management. Processors must invest in creating a safe workplace by properly maintaining equipment and training personnel.
Best Practice: The equipment vendors are responsible for providing owners with Operations & Maintenance (O & M) Manuals for all equipment supplied. Copies of the documents should be purchased and the management team and staff should be thoroughly trained by each equipment supplier concerning all safety issues associated with operating the equipment/system prior to startup. The staff should have a monthly safety meeting to review issues that may have caused an unsafe situation and to remind the staff of safety issues. Safety issues can range from immediate life-threatening situations to repetitive activities that could result in ergonomic problems. Common safety issues and risks associated with wood processing operations in order of descending priority are as follows:
· Size-Reduction Equipment: Attempting to relieve jams without proper shutdown of equipment, generation of unanticipated projectiles, and equipment or power malfunctions. · Rolling Stock: Violating established safety zones and improper or dangerous equipment operation. · Conveyors: Attempting to relieve jams without proper equipment shutdown, walking atop conveyors to expedite personnel movement, and improper shutdown of equipment for repairs. · Ergonomic Issues: Improper lifting to reach or pickup items and repetitive motions. · Plant Environmental Conditions: Exposure to dust and loud noises.
Implementation: Only trained personnel should operate appropriate mobile equipment and the size-reduction processing system. When new equipment is purchased, a sufficient number of O & M manuals should be ordered from the vendor and staff should be trained on the safe operation of the equipment. The staff should know all safety and maintenance procedures prior to using any processing equipment. There are numerous unsafe situations that are not related to a single piece of equipment, but rather with the facility’s layout and operation of the system. These specific situations need to be documented, communicated, and improved or managed through the facility’s safety manual and training system.
An important part of the preventative maintenance procedure is a regular “walking inspection” of the total processing system. Well-trained operations and maintenance personnel can detect potential problems from unusual sounds detected during regular inspections. Freeing jams at size-reduction equipment must be conducted only after the primary rotating mass is shutdown. Proper hooding and hanging curtains of a heavy plastic or rubber material allows input flow while minimizing the potential ballistic impact of a projectile. Operating staff should be carefully protected from projectiles. Additionally, wearing hard-hats and safety glasses should be mandatory. In the case of an equipment or power malfunction, the re-startup sequence should require manual intercession and the equipment train should include safety interlocks and enunciators. Rolling stock traffic should be carefully controlled. Because of the size of this equipment, it’s imperative to restrict its operation to within certain work safety zones of the plant. This safety measure avoids hazards with other equipment or on-site labor. Rolling stock operators must maintain a controllable speed and vigilance, especially when schedules are tight. Safety should always come first. The belt conveyors at a processing facility present a number of safety issues. No one should attempt to perform manual maintenance or clean-up unless the conveyor has been stopped and the electrical control switch locked out. All personnel should know the location and operation of all emergency control and safety devices. No person should ride on, step on, or cross over a moving conveyor nor walk or climb on any related structures.
Facilities that employ a considerable amount of manual labor along sorting lines need to be aware of the ergonomics of staff with regard to back injuries and manual sorting related issues. The long-term and repetitive motion of staff must be considered in the staffing plan and the movement of staff around the facility to reduce ergonomic issues. Switching sorting staff from small objects to larger objects, from left-hand motions to right-hand motions, from bent to more upright inspection functions, all create diversity of action and help reduce ergonomic related problems. Processing equipment can be hazardous due to noise, dust, and explosions. Federal OSHA standards limit noise over an 8-hour working day. Operators should wear ear protection and noise reduction should be considered in facility design (such as enclosures for laborers). Wearing a face mask or respirator while working near dust sources can reduce the exposure. The appropriate number of air changes in closed buildings is critical; exhaust fans and louvers are good ventilation provisions. Some operations have chosen to open the walls of the building that houses the processing line. Dust build-ups and potential for explosions requires a regular plant clean-up program and continuous ventilation.
Benefits: A safe workplace requires both safety equipment and appropriate staff procedures and protocol. Once attained and maintained, the most crucial benefits of a safe workplace for wood waste processors are high staff morale, a willingness to fix problems on a preventative or rapid-response basis, the necessary staff flexibility to respond to new challenges, and higher overall productivity.
Application Site: Processing Facility.
Contact: For more information about this Best Practice, contact CWC (206) 443-7746, e-mail info@cwc.org. References: 1. American National Standards Institute. New York, NY. 2. American Society of Testing Methods (ASTM). Philadelphia, PA. 3. American Society of Mechanical Engineers (ASME). New York, NY. 4. Conveyor Equipment Manufacturers Association (CEMA). Manassas, VA. 5. National Safety Council. Washington, DC. 6. OSHA Occupational Safety and Health Standards. Washington, DC. 7. Taylor, Mike. National Association of Demolition. Doylestown, PA.
Issue Date / Update: March 1997 |
