Four Tips to Protect Workers from Dangerous Manufacturing Dust
This post was sponsored by Camfil APC.
Many industries—from food to pharmaceutical, metals to mining, paperboard to packaging—have a common challenge: dust generated from manufacturing and processing operations threatens worker health and facility safety.
To maintain air quality, facility operators must collect and contain airborne dust particles to protect employees and meet regulatory compliance. Here are five steps facility managers and production engineers can take to control nuisance and hazardous dusts.
1. Analyze the Dust
Understanding the characteristics of the dust that a process produces is vital for ensuring operational safety. Many dusts are explosive or flammable, or can cause health issues if not properly controlled. Because each type of dust is different, it will have unique safety requirements, regulations, and containment equipment specifications. The best way to know how to handle dust is to have it analyzed.
The burden of proof is on facility operators to demonstrate that their process dust is not combustible. They can accomplish this by having the dust tested by a valid third-party testing lab and keeping records on file proving that it is not combustible. If the dust is determined to be combustible, the facility’s dust collection system should be evaluated by an expert to identify the appropriate explosion-protective equipment that can be added to the collector.
To determine the best dust collection system and filters for the operation, it is also important to analyze specific dust characteristics such as particle shape, gravity, size, abrasiveness, and moisture level. Often, dust collection equipment suppliers can conduct bench testing of dust samples and work with facility operators to specify the best system for the application.
2. Know the Regulations and Guidance
OSHA’s General Duty Clause mandates that employers offer employees a safe workplace free from recognized hazards that can cause death or serious physical harm. In addition, OSHA has permissible exposure limits for many types of hazardous contaminants, including dusts.
OSHA has established PELs based on an eight-hour time-weighted average (TWA) for hundreds of dusts, ranging from nonspecific or “nuisance” dust to highly toxic substances. They are listed in OHSA’s annotated PELs tables. OSHA PEL requirements determine the minimum level of filtration efficiency the dust fume collector must achieve. To make sure a dust collector can help meet PEL requirements, facility operators should request a written guarantee from the system provider stating the maximum emissions rate for the equipment over an eight-hour TWA. Filter efficiency stated as a percentage is not an acceptable substitute, even if the supplier promises 99.9 percent efficiency. That’s because OSHA only wants proof that the quantified amount of dust in the air is below the PEL.
OSHA also has a National Emphasis Program (PDF) that outlines policies and procedures for inspecting workplaces that create or handle combustible dusts with the potential to cause a deflagration, fire, or explosion.
The National Fire Protection Association is an international organization dedicated to preventing death and property damage from fire, electrical, and other related hazards. There are several NFPA standards you need to be aware of if your facility handles combustible dust. The best place to start is NFPA 652, the standard that covers the requirements for managing combustible dust fires and explosions across industries, processes, and dust types. One of the key requirements of NFPA 652 is completing a dust hazard analysis. Completing this analysis helps you better understand your dust and ensures that your dust collection system is outfitted with all necessary safety controls to prevent or mitigate deflagration and explosion. (For more information about NFPA 652, read “A New Tool for Preventing Combustible Dust Incidents” in the February 2020 issue of The Synergist.)
Food and pharmaceutical manufacturing processes can generate potentially explosive dust, as well as cross-contaminate other items being produced in the same facility. The Food and Drug Administration’s Food Safety Modernization Act requires food processing facilities to implement measures to ensure that contamination hazards are minimized or prevented.
EPA regulates exhaust systems, including those for dust collectors, that vent outdoors. Mandates like National Emission Standards for Hazardous Air Pollutants (NESHAP) Rule 6X ensure that hazardous air pollutants produced by metal fabrication industries, known as metal finishing hazardous air pollutants, are fully filtered or contained before emissions are released outdoors.
3. Mitigate Combustible Dust
If the facility produces or processes combustible dusts, the dust collector must be equipped with deflagration protection, such as explosion venting. That’s because the dust collector itself can be a source of explosion. NFPA 68 focuses on preventing structural failure of the enclosure to minimize injury to personnel. This standard requires explosion venting of combustible gases and pressures resulting from a deflagration within the dust collector.
4. Optimize Safety Equipment
In addition to selecting and installing a dust collection system designed specifically for the application, other types of safety equipment can optimize the system:
- If your facility is handling highly toxic dust, a bag-in/bag-out (BIBO) containment system may be required to isolate workers during filter change-out.
- To optimize fire and explosion protection, operators can utilize flame-retardant filter media, spark arrestors, and sprinkler systems.
- Lockout/tagout doors can prevent injury or exposure caused by inadvertently opening doors during a pulse cleaning cycle.
- OSHA-compliant railed safety platforms and caged ladders can prevent slips and falls when workers access the dust collector for service.
- A safety monitoring filter prevents collected dust from re-entering the workspace if there is a leak in the dust collector’s primary filtering system. A safety monitoring filter is a required component of a dust collection system that recycles air downstream of the collector.
These are just a few key points for optimizing dust collection safety. Because there is so much equipment and regulatory information to consider when it comes to mitigating dust risks, it is important to consult with an experienced dust control expert to properly assess the facility’s needs and design a dust collection system for specific applications and dusts.