Food processing creates a lot of dust, and that dust is not only a potential contaminant — it’s also a key ingredient in the perfect recipe for an explosive disaster. 

To understand what role vacuums play in minimizing contamination and complying with combustible dust standards, we talked to Carson Anderson, the National Sales Manager of the Industrial Vacuum Division at Kärcher North America Inc.

Kärcher, a German company founded in 1935, is a leading manufacturer of cleaning equipment, with products ranging from floor care equipment to pressure washers to industrial vacuums. “We have a full range of products in the industrial vacuum space — single-phase, three-phase, and pneumatically powered products,” Anderson says. “So we have a solution for most food processing applications.” And with service technicians throughout the U.S., Kärcher is able to offer its customers on-site service and support.

The dangers of combustible dust

Dry processes, especially those in the bakery industry, generate a lot of dust from grains, sugar, flour, and a wide range of other combustible materials. If enough of these micron-sized particles collect in a room or an enclosed piece of equipment, it can put the whole plant at risk. Known as combustible dust, these particles can ignite and cause catastrophic explosions. 

“Let's take bread for instance,” Anderson explains, “where you use a lot of yeast, flour, maybe even some sugar. You have significant volatility attached to all that dust, especially when it's in a very fine form. All you need is an ignition source — someone lighting a cigarette, accidentally backing a forklift into a metal pole, or maybe an electrical arc off the light fixture that's malfunctioning — anything that causes a spark could potentially ignite this dust and create an explosion.” 

And you don’t have to look far to find incidents of plants and employees lost to this hazard. According to the Chemical Safety Board, there were 105 combustible dust incidents between 2006 and 2017. Findings of the 2018 Combustible Dust Incident Report show that food dusts are making up a growing percentage of global combustible dust fires and explosions.

Implementing NFPA 652

OSHA doesn’t have a combustible dust standard, but it does have a National Emphasis Program dedicated to the hazard. To avoid citations and fines for combustible dust hazards, facilities must comply with National Fire Protection Association (NFPA) 652: Standard on the Fundamentals of Combustible Dust, which Anderson refers to as the “blueprint for how plants should address issues regarding combustible dust.” 

Anderson says that the food industry, in general, is conscious of the issues surrounding combustible dust and the need to mitigate this hazard. But for plants that haven’t yet adopted these practices, time is running out. By September 7, 2020, plants must complete a Dust Hazard Analysis (DHA) and start taking measures to reduce that dust. 

“OSHA is going to consider combustible dust as any dust with a Kst value of more than zero,” Anderson says. The Kst value measures the volatility of dust, and such a strict standard could lead to drastic changes for plants that aren’t prepared. “It will change the landscape of how plants have to deal with fugitive dust in their facilities because, at that threshold, any dust will be considered potentially combustible.”

Among other things, NFPA 652 sets standards for equipment. To be NFPA 652-compliant, portable vacuum cleaners must meet seven requirements:

  1. Materials of construction must be conductive, with certain exceptions.
  2. Hoses shall be conductive or static dissipative.
  3. All conductive components, including wants and attachments, shall be bonded and grounded.
  4. The fan or blower shall be on the clean side of the primary filtration media or wet separation chamber.
  5. Electrical motors shall not be located on the dirty side of the primary filtration media or wet separation chamber unless listed for Class II, Division I locations.
  6. Where liquids or wet materials are picked up by the vacuum cleaner, paper filter elements shall not be used.
  7. Vacuum cleaners used for metal dusts shall meet the requirements of NFPA 484.

Kärcher is committed to helping plants get up to standard. “So if an OSHA rep walks into a facility and says, ‘Is that vacuum 652 compliant?’ The plant manager can answer with full confidence: ‘Yes.’”

Complete cleanup solutions

To take on challenges like combustible dust, cross-contamination, and areas that are difficult to clean, you need a vacuum built to the highest standards. Kärcher’s powerful vacuums tackle these industry challenges from a few different angles:

  • Filtration: Quality filtration is key to keeping particles out of the environment. Cheaper vacuums with poor filtration systems often cycle many of those particles back into the air. Kärcher solves this with advanced HEPA filtration. “First, particles would have to pass through the main filter, which filters down to 1.5 microns,” Anderson explains. “Anything that makes it through that filter is collected by the HEPA filter, which is at 0.3 microns.” This multi-stage filtration system ensures that once dust is collected, it stays collected.
  • Overhead cleaning: “If somehow shaken or disturbed, dust that collects on pipes, L-beams, and light fixtures can fall back into the process,” Anderson says. Kärcher offers vacuum accessories to get to these hard-to-reach areas safely.
  • Continuous duty: Typically vacuuming is a manned operation, but continuous duty vacuums can be integrated directly into the manufacturing process. “Kärcher offers an assortment of continuous duty vacuums that can be plumbed in or piped into a system,” Anderson notes. This eliminates the need for employees to go in after the process and manually clean out dust and debris.

Anderson has been to PROCESS EXPO several times. “I'm a big proponent of PROCESS EXPO,” he says. “Everyone at Kärcher is looking forward to attending this year’s show. I think it's a tremendous fit for Kärcher for the type of product we're introducing in North America. I think it's going to be a great show for us.”

You can find Kärcher at Booth #4162 to learn more about NFPA 652-compliant industrial vacuum solutions.