Food Processing Industry Dust Collection

Some of the most pressing concerns include the following.

• Cross-contamination: Cross-contamination is a particular concern in the food industry. Many common food products provoke allergic reactions in susceptible people, and sometimes these reactions can be dangerous or even life-threatening. That makes it imperative to prevent cross-contamination of production lines with dust from other processes. Some of the most common food allergens found in food processing dust include wheat (gluten), nuts (peanuts, tree nuts, and other types), eggs (eggshell dust or dehydrated egg products), dairy (dehydrated milk), soy and sesame. Spices and food additives may also cause serious allergic reactions in some people. Beyond the allergen concern, it is simply undesirable to have food products contaminated with dust from other processes. Contamination with excess dust may impact food quality, flavor and desirability.
• Microbial growth: The spread of food-borne pathogens is another very real concern for the food processing industry. Food products create an ideal breeding ground for many different kinds of microbes, including yeasts, molds and bacteria. While “dry” processes in the food industry (such as grain transport, cereal production and packaging, etc.) are not as susceptible to spreading pathogens as “wet” processes (like meat and dairy production), dry and powdered foods have been implicated in a number of food-borne illnesses, including salmonellosis and Enterobacter sakazakii. These microbes, along with many yeasts and molds, can thrive in environments with even very low levels of moisture. Packaged foods especially susceptible to microbial outbreaks include potato flakes and powdered milk and infant formula. However, many dangerous molds thrive on grain products such as corn and wheat. Dust control is important to reduce the spread of microbial pathogens in food production lines. Uncontrolled dust on window ledges, floors and other surfaces can become a breeding ground for dangerous yeasts, molds and bacteria. If this dust is allowed to re-contaminate production lines, pathogens can easily end up in the final product.
• Combustion risk: Many of the dusts created during food processing are highly combustible. That means they can generate an explosion when allowed to concentrate in the air or inside a dust collection machine. In fact, some of the most common dust types in the food processing industry—including grain flours, powdered milk, corn starch, wheat starch, sugar, tapioca, whey, cocoa powder and many spices—are considered to be highly (The explosion at the Imperial Sugar refinery in Georgia in 2008 led to the passage of the 2008 Combustible Dust and Fire Prevention Act.) Special care must be taken when collecting combustible food processing dusts to minimize the risks of an explosion inside the dust collector.
• Health hazards: While most bulk ingredients (such as grains, soy and potatoes) aren’t associated with health hazards, some substances used in the food processing industry are considered to be hazardous with prolonged and intensive exposure, especially by inhalation. These include spices, flavorings and additives that are not problematic when ingested in small amounts but can cause problems for workers in the food processing industry who are exposed to them all day long. For example, the compound diacetyl—a commonly used component of butter flavorings—has a well-documented history with lung disease. The condition in the industry has come to be called “popcorn lung.” Other chemical additives and flavorings used in the food processing industry can cause irritation of the lungs and mucus membranes or contact dermatitis. Cinnamon, for example, contains a volatile oil that can cause asthma, skin and eye irritation; it is often processed in special rooms due to the exposure hazards.
• Nuisance dust: Just because a food dust isn’t considered to be toxic or hazardous doesn’t mean it’s not a problem. All food-related dust can still create health problems—such as lung irritation and aggravation of asthma symptoms—when inhaled. Some types of food dusts, especially flour and nut dust, can also trigger allergic reactions in susceptible employees, which can get worse over time with continued exposure. Uncontrolled dust of any type is also a housekeeping and sanitation consideration. It is especially important to control dust during the packaging process, including box filling and bag filling; excess dust in or on the packaged product is highly undesirable from a consumer perspective.

• Food Safety: The Food Safety Modernization Act requires food processors to have controls in place to reduce cross-contamination of food allergens and prevent microbial contamination. These include preventative controls (which include control of airborne dust, prevention of dust build-up on surfaces and in production lines, and sanitation of equipment and surfaces) as well as processes for food safety evaluation, problem identification and mitigation, and food recalls. Food processors are subject to annual inspections to ensure that they have the right controls in place. Companies that do not comply with FDA food safety requirements are at risk of large fines or even suspension of their registration.
• Nuisance dusts: Many food processing dusts fall under the OSHA definition of “nuisance dusts,” which are regulated under the general particulate matter concentration limits set by OSHA. The general limit for “Particulates Not Otherwise Regulated” (PNOLs) is 15 mg/m³ (8-hour TWA limit) for total particulate and 5 mg/m³ for respirable particulates. Employers must also follow general Housekeeping standards (OSHA 1910.22, Walking-Working Surfaces) to prevent accumulation of dust on surfaces.
• Flavoring Substances: OSHA has not developed specific Permissible Exposure Limits (PELs) for most chemicals used in food processing. However, because of the safety concerns for workers exposed to fine respirable dusts and volatile organic compounds (VOCs) produced by many chemical flavorings and additives, OSHA has issued a Safety and Health Information Bulletin titled Occupational Exposure to Flavoring Substances: Health Effects and Hazard Control. While these recommendations are not binding, OSHA strongly suggests that companies where workers are exposed to potentially dangerous food additives put engineering controls in place, including appropriate ventilation, isolation of processes (such as batch mixing) that produce dust or fumes, and access control for areas where these processes occur.
• Combustible dusts: Combustible dusts are regulated under OSHA’s General Duty Clause (Section 5(a)(1)) with additional requirements under the Hazardous Locations (§1910.307), Hazard Communication (§1910.1200) and Housekeeping (§1910.22) standards. In addition, manufacturers dealing with combustible dusts must follow National Fire Protection Association (NFPA) standards for prevention of fires and explosions. Food dusts fall under NFPA 61, Standard for the Prevention of Fires and Dust Explosions in Agriculture and Food Processing, as well as NFPA 654, Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing and Handling of Combustible Particulate Solids. Dust collection systems for food processing dusts must also meet NFPA 68, Standard of Explosion Protection by Deflagration Venting, and NFPA 69, Standard on Explosion Preventing Systems. OSHA’s Combustible Dust National Emphasis Program (NEP) outlines policies and procedures for inspecting workplaces that create or handle combustible dusts.
• Other Regulations Specific to the Food Industry: OSHA has issued additional regulations for Grain Processing Facilities (1910.272) and Bakeries (1910.263). These regulations are primarily concerned with the high combustion risks of grain dust and flours, sugars and spices used in bakeries. Grain handling facilities must have a written plan for control of fugitive grain dust, including engineering controls and housekeeping measures to prevent the accumulation of dust both in the air on surfaces.

• Collect dust as close to the source as possible to prevent propagation throughout the facility. This may involve enclosing certain processes or areas to enable efficient source capture and filtration.
• Control airflow to prevent airflow and dust movement from dirtier parts of the process to cleaner parts of the process. In general, this means using positive and negative pressure zones to prevent air from moving from earlier processes (such as dry mixing) to later processes (such as packaging).

Each of the three major areas of the food processing industry have unique considerations when it comes to dust control.

• Bulk Food Ingredient Handling (transport, silo filling and dry mixing)
• Processing (milling, cutting, grinding, batch mixing, blending, and cooking)
• Packaging (box filling, bag filling, carton filling)