It’s important that the air remains clean in every workplace, and this is especially important in the pallet industry. There are a number of hazards related to wood dust in the pallet industry, health hazards, such as respiratory exposure; physical hazards such as slipping, tripping and falling; and fire and explosion hazards.
Health Hazards from Wood Dust
The most important reason to have clean air is to ensure that employees are not exposed to hazardous dust in the air that they breathe. Wood dust can cause irritation in the airway that can result in everything from a mild irritation causing a cough and allergic reactions to skin cancer and respiratory diseases. Heat treated for pallet wood is much safer than other treatments for preservation, such as the chemicals used in pressure treatment, fumigation, and fire resistance. Anytime a hazardous chemical is used in wood treatment, it will increase the exposure hazards when the wood is disturbed by processes such as cutting and sanding, thus creating dust and fine particles that become airborne.
The OSHA Respiratory Protection Standard, 29 CFR 1910.134, defines the regulations for the respiratory exposure of wood dust. OSHA regulation 29 CFR 1910.1000 (Table Z-1) requires wood mills to limit worker exposure to wood dust, with a Permissible Exposure Limit (PEL) for total dust at 15 mg/m³ and the respirable fraction at 5 mg/m³ as an 8-hour time-weighted average (TWA).
Key Requirements and Standards:
- Engineering Controls: OSHA requires using engineering controls (e.g., dust collection systems, local exhaust ventilation) as the primary method to control dust, rather than relying solely on respirators.
- Respiratory Protection (29 CFR 1910.134): If engineering controls cannot reduce dust levels below the PEL, employers must implement a respiratory protection program.
Specific Limits:
- Total Dust: 15 mg/m³ (8-hour Time Weighted Average or TWA).
- Respirable Fraction: 5 mg/m³ (8-hour TWA).
- Western Red Cedar: 2.5 mg/m³ (sensitizer).
- Hazardous Species: Certain hardwoods (oak, mahogany, birch, walnut, etc.) are linked to nasal cancer, requiring strict exposure control.
- NIOSH Recommendation: 1 mg/m³ total dust.
Employers must also ensure, under 29 CFR 1910.134, that respirators are NIOSH-certified, properly fitted, and that employees are trained and medically evaluated. This is discussed further in the Written Respiratory Program portion of this article.
Physical Hazards
Another common hazard due to wood dust and particles is eye injuries. Eye injuries from wood particles becoming airborne are one of the most common recordable injuries in the wood products industry. Ventilation systems and requiring safety glasses in production areas are key factors in reducing eye injuries.
Dust accumulation on working and walking surfaces creates a slip, trip and fall hazard. Slips, trips and falls are common recordable injuries throughout the pallet industry as well as general industry. Good housekeeping is key to reducing these hazards.
Fire and Explosion Hazards from Wood Dust
Another hazard from dust and fine particles is the fire and explosion hazard. I will never forget emptying the dust collector from my wood shop into a burning barrel. Little did I know, there was an ember that had been in the barrel from burning several days previous. When the fine dust from the collector was dumped, it had the perfect mixture of combustible dust and air to create an explosion when an ignition source was present. No one was injured, but an important lesson was learned. We’ve all heard of wood mills, grain facilities, and mills exploding from airborne dust, and facility fires having rapid progression due to dust accumulation on interior structure material and supports. An additional fire hazard exists when dust accumulates on machinery. A hot bearing with wood dust on it, or hot work being completed with wood dust in the vicinity, is all it takes to start a fire. Remember, a hot ember can smolder for hours before igniting the dust particles around it. A scheduled fire watch after hot work is extremely important in the reduction of fires.
On January 30, 2023, the Occupational Safety and Health Administration (OSHA) revised the Combustible Dust National Emphasis Program with CPL 03-00-008.
The revision provided instruction on policies and procedures for inspecting workplaces that generate or handle combustible dust and for determining whether such workplaces have addressed fire, flash fire, deflagration, and explosion hazards associated with combustible dusts.
These dusts include, but are not limited to, metal dust, such as aluminum, magnesium and some forms of iron dust; wood dust; coal and other carbon dusts; etc.
Facilities must comply with OSHA and National Fire Protection Association (NFPA) standards. The NFPA Standard 652 requires employers to conduct a Dust Hazard Analysis (DHA) for any combustible dust. OSHA does not have a requirement for a DHA, but NFPA requirements are enforced by state and local fire marshals and inspectors.
These requirements include:
- The DHA shall be performed or led by a qualified person.
- The Explanatory Material in Annex A (not enforceable, but provided for clarification) elaborates:
- The qualified person who is leading or performing the DHA should be familiar with conducting a DHA. The qualified person should also be familiar with the hazards of combustible dust. Typically, a team performs a DHA. For some processes this team might be as little as two persons, or for larger and more complex processes, the team might require many more than two persons. This team is made of a variety of persons whose background and expertise can include the following: familiarity with the process, operations and maintenance, process equipment, safety systems, history of the operation, properties of the materials and emergency procedures.
Strategies to Combat the Hazards of Wood Dust Exposure
Addressing workplace exposure hazards involves applying the Hierarchy of Controls, prioritizing the elimination or substitution of hazards, followed by engineering controls (ventilation, isolation), administrative controls (training, rotation), and finally, Personal Protective Equipment (PPE).
Engineering Controls (implement physical change to the workplace, which eliminates/reduces the hazard on the job/task)
- Change process to minimize contact with hazardous chemicals.
- Isolate or enclose the process to reduce airborne particles.
- Use of wet methods to reduce generation of dust or other particulates.
- Use dust ventilation systems.
- Air-flow maintenance.
- Install industrial fans to help control dust accumulation and direct flow.
- Use fume hoods for chemical processes.
Administrative and Work Practice Controls (Establish efficient processes or procedures)
- Rotate job assignments.
- Adjust work schedules so that workers are not overexposed to a hazardous chemical.
- Provide written safety programs, policies and procedures for the reduction of dust exposure.
- Provide employee safety training.
- Maintain good housekeeping practices.
- Scheduled cleaning of all structural surfaces to reduce buildup of combustibles.
Personal Protective Equipment (Use protection to reduce exposure to risk factors)
- Use protective clothing for chemical exposures.
- Wear respiratory protection.
- Use gloves.
- Wear eye protection.
Remember, PPE is the last line of defense and cannot be your company’s sole answer to resolving your hazardous dust exposures.
Editor’s Note: Jary Winstead is a safety consultant, author and trainer who serves a variety of industries, including the forest products sector. He owns Work Safety Services LLC and can be reached at SAFEJARY@gmail.com.
