Food Processing: Cutting, Grinding, Blending and Batch Mixing

Introduction to Dust Control for Food Processing and Manufacturing

The middle stage of the food processing industry is where bulk ingredients are transformed into edible products. During the processing stage, food manufacturers prepare and combine ingredients and add flavorings and additives such as stabilizers and preservatives.

Some of the specific processes included in this stage include:

  • Milling
  • Cutting
  • Grinding
  • Batch mixing
  • Blending
  • Cooking

The dustiest processes at this stage include cutting and grinding and batch mixing of dry ingredients. Transport points and conveyors can also become points where dust from dry ingredients becomes airborne or collects on surfaces.

Dust Collection Challenges for Food Cutting, Grinding, Blending and Batch Mixing

The dust control challenges at this stage of the food processing industry vary widely depending on the ingredients being handled, the actual processes used and the physical layout of the facility where food production activities take place. Food safety and cross-contamination concerns are generally the biggest considerations at this stage.

  • Cross-contamination: Because many foods are prepared and processed in manufacturing facilities that are used for multiple food products, special care must be taken to avoid cross-contamination of foods and ingredients with dust from other products. This is important from both a food quality perspective and a safety perspective. In addition to causing flavor and quality concerns, fugitive food dusts can create an allergen risk that can be dangerous or even life-threatening for susceptible people. Because of this risk, the FDA requires food processing facilities to take steps to ensure that food products are not accidentally contaminated with potential allergens not noted in the official ingredient list. 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.
  • Microbial growth: Food pathogens are a particular concern at this stage of the food processing industry. Food products create an ideal breeding ground for many different kinds of microbes, including yeasts, molds and bacteria. 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. Because of the way food ingredients are mixed and processed at this stage, it is easy for microbial contamination to quickly spread from a single location all through production lines. Once that happens, food processing facilities will typically need to shut down entirely to decontaminate all affected lines.
  • Combustion risk: Many 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 That means they can generate an explosion when allowed to concentrate in the air or inside a dust collection machine, conveyor system or enclosed production area.
  • Health hazards: While food ingredients and additives must be proven safe for ingestion in normal amounts, that doesn’t mean that food processing dusts can’t be hazardous. Many spices, flavorings and additives used during this stage of the food production process are considered to be hazardous when inhaled or with prolonged exposure in a manufacturing environment. 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: 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.

Flour Dust

Food Processing Regulations for Food Cutting, Grinding, Blending and Batch Mixing

The food processing industry is highly regulated. Companies involved in milling, cutting, grinding, batch mixing, blending and cooking of food ingredients are subject to both food safety regulations from the Food and Drug Administration (FDA) and U.S. Department of Agriculture (USDA) and occupational safety regulations from the Occupational Safety and Health Administration (OSHA) and National Fire Prevention Association (NFPA). Some of the most critical regulations for this stage of the food processing industry are as follows.

  • Food Safety: Food processors must comply with the FDA’s Food Safety Modernization Act, which requires food processors to have controls in place to reduce cross-contamination of food allergens and prevent microbial contamination. Under this act, food processing facilities must be registered with the FDA and are subject to annual inspections to ensure that they have the right controls in place. Some of the requirements for food processors and manufacturers include control of airborne dust, prevention of dust build-up on surfaces and in production lines, and sanitation of equipment and surfaces.
  • Bakeries, Sugar and Spices: OSHA has issued additional regulations for Bakeries (1910.263) because of the high combustion risks of flours, sugars and baking dusts.
  • Flavoring Substances: 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, spices and flavorings 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.
  • 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.

Read more about regulations for food processing dusts.

PleatLock Cartridge Filters

Dust Control Solutions for Food Cutting, Grinding, Blending and Batch Mixing

Dust control solutions for companies involved in processing food ingredients and manufacturing finished food products will vary depending on the type and volume of dust produced, the specific cross-contamination and allergen concerns at the facility, the processes being used and how easily those processes can be enclosed. These are a few of the special considerations in designing a dust control solution for food processors and manufacturers.

  • Enclosure and source capture: At the processing stage, it is helpful to have hoods or enclosures around dust-creating processes such as grinding or mixing and at transfer points and conveyors. These might have to be custom-built to accommodate the production line. In general, food processing dust should be captured as close to the source as possible. It can also be helpful to isolate sequential production processes to prevent dusts from migrating from earlier processes (such as cutting and grinding of ingredients) to later processes (such as cooking or baking). This can be accomplished using positive and negative pressure zones to control airflow between processes.
  • Dust collector location: The dust collector is typically located outside in food production facilities. This is to prevent dust from re-contaminating the facility during filter changes or bin emptying. The filtered air is also typically vented outside to reduce cross-contamination and microbial contamination risks.
  • Makeup air and filtration: Because air is usually vented outside, a makeup air system will also be required to maintain the right air pressure inside the facility. HEPA filtration in the HVAC or makeup air system will ensure that air that enters the facility is clean and does not introduce any contamination into food processing lines.
  • Filter media selection: Selecting the right filter for the dust collection system is also very important at the processing stage. Many food dusts are hygroscopic, meaning they readily absorb moisture from the air. If the environment is very humid or food production processes release water vapor into the air, the dust hitting the filters will be very wet. Wet dust tends to cake or (in the case of sugary dust) form a crust on the filters. A washable filter media can extend filter life considerably in these situations.
  • Combustion mitigation: Special care must be taken when collecting combustible food processing dusts to minimize the risks of an explosion inside the dust collector. The dust collector should be equipped with a deflagration system to prevent pressure waves from propagating back into the facility if an explosion should occur.

Dust collection for food processing must be customized for the process and production line. Our engineers will evaluate your processes and help you select the right dust collector and filter media. We can also design an industrial ventilation and makeup air solution for you to ensure optimal dust collection, reduce cross-contamination concerns and mitigate health and safety hazards.

RoboVent can also help you meet OSHA and NFPA regulatory requirements and safety guidelines for management of combustible dusts. We can conduct a dust hazard analysis (DHA) for your operations under the NFPA Combustible Dust Standard (NFPA 652) and put dust control systems in place to mitigate the risks of a combustible dust explosion from food processing dust. We can also help you evaluate your processes and design a dust control solution that will minimize the risks of cross-contamination and microbial growth in food production lines.

Our experienced air quality engineers will work with you through the whole process, including needs analysis, system design and engineering, collector and ductwork installation, filter selection, HVAC system integration, startup and commissioning, and aftercare and service.

Solutions

Senturion®

Senturion is the most flexible and versatile industrial dust collector on the market today.

PleatLock Cartridge Filters

PleatLock Dust Collector Cartridge Filters

RoboVent's premium filter engineered to provide the best filtration protection for your plant and employees. A widened pleat and proprietary filter media help deliver top performance.

Deflagration System on Fusion 4.5

Deflagration System

Protecting your workers and facility from the risks of combustible dust, RoboVent's Deflagration System employs multiple devices and technologies to mitigate dust explosions.