Combustible dust, (or explosive dust), cleaning, is a required preventative good housekeeping and maintenance program, in manufacturing and production facilities. This minimizes safety hazards, potential flash fires, and catastrophic dust explosions, in addition to maintaining Indoor Air Quality. Combustible dust is fine particulate dust, which is generated from products such as wood, metals, grains, agricultural, chemicals, plastics, paper, and carbonaceous products. The manufacturing and production facilities equipment and machinery, pulverize, mill, grind, crush, macerate, and cut the bulk product. In return, dust is generated, and accumulates on all equipment and facility structure surfaces. The fine powder dust, which is suspended on the higher, inaccessible and unnoticeable surfaces, is the most problematic. Yet the most hazardous, especially when a primary upset or explosion generates a sonic pressure wave that suspends these particles into the path of a flame front (reaction front), which causes a devastating secondary dust explosion.
In addition to the fire and explosion hazards of dust, the industrial hygiene aspect of fine particles can impact and affect, the facility workers health, leading to illnesses, and injuries. The Bureau of Labor Statistics reports that 6.1 percent of private-sector employees suffered 5.7 million workplace injuries and illnesses in 2000. Forty-six percent of those injury cases required days away from work for recuperation or restricted work activity.
J. Paul Leigh of the Stanford Medical Center notes that businesses spend $170.9 billion a year on costs associated with occupational injuries and illnesses — expenditures that come straight out of company profits. Injuries and illnesses increase workers’ compensation and retraining costs, absenteeism, and production faults. They also decrease productivity, morale, and ultimately, profits.
Fortunately, statistics from injury and illness reports filed with OSHA show that workplaces that establish safety and health management systems reduce their injury and illness costs by 20 to 40 percent.
"In today’s competitive business environment," says OSHA Administrator John L. Henshaw, "the black-and-blue of workplace injuries can be the difference between operating in the black and running in the red."*
High ceiling and surface cleaning, Air Conveyance Cleaning, Dust collector cleaning, Conveyor Belt cleaning, Silo tank cleaning, Lab Fume Hood cleaning, and dust control vacuuming, are some of the services, that may be required to clean the combustible dust. These services help prevent airborne dust and particulates, from accumulating, in the manufacturing and production facilities. These services may also help promote equipment longevity, may decrease utility costs for operating equipment, may increase the brightness of lighting, may stabilize insurance rates, and may allow a greater Return On Investment on manufacturing equipment.
Combustible dust cleaning should be performed by a certified and trained cleaning company. The certified training should be similar to the N.A.D.C.A., I.A.Q.A., O.S.H.A., and I.I.C.R.C. cleaning standards. Additionally, the certified cleaning contractor, should have the proper Industrial and Commercial cleaning equipment. Most importantly is an industrial, explosion-proof, dust collecting H.E.P.A. vacuum, as the main piece of equipment. Broom sweeping and compressed air, is not a viable means of cleaning combustible dust, by the NFPA 654 Combustible Dust Standard. The act of broom sweeping, and compressed air, actually stirs up dust and particulate into the air, which may create more issues with sensitive equipment that provide ignition sources, and possible dust explosions. High reach equipment, such as High reach platforms,
Scissor lifts, articulate booms, scaffolding, fiberglas extension ladders, and fiberglas A-frame ladders for the interior work, are necessary. Standing and portable floodlights may be required for night work, and hard to see areas.
Performing combustible dust cleaning requires several important precautionary measures. The first and most important procedure is safety. Preventing Static Electricity, sparking, and any electrical charge, is the first preventative step. Proper grounding of in-house electrical systems, equipment, forklifts, high reach equipment, vacuums, extension cords, and lighting, is mandatory, by the NFPA 654 Standard.
Next, information on the fire and explosion hazards concerning the ignition sensitivity and explosion severity of the product must be acquired from the MSDS sheets. If this information is not in the MSDS then
testing and sampling of the powder and bulk dust particulate is required.
The simple act of dragging a piece of metal, across a concrete floor, can create a spark, which can lead to a dust explosion. Proper lock-out/tag-out documentation, slip and fall prevention, high reach and harness protection, confined space awareness, are some of the safety concerns, with OSHA regulations. Donning proper PPE, including safety lanyards and harnesses, hard hats, safety glasses, ear protection, disposable gloves, special coveralls, and steel toe boots, are essential protection basics. Placing orange safety cones, and Yellow Caution tape, in the working areas, are required to inform hazardous conditions.
Preparation is one of the most critical procedures of combustible dust cleaning. Proper preparation, will contain dust and particulate, and will alleviate a possibly unhappy customer. Preparation materials will include covering your customer’s equipment, contents, walls, and floors. The covering will also serve as a containment barrier, for any possible recontamination. Trash can containers, or 55-gallon drums, with liners, can be used to collect the debris.
Combustible dust cleaning, involves several main aspects of cleaning. First, always work from ceiling, to walls, to floor. The floor is considered the easiest and last part of the cleaning procedure. All corrugated, metal ceilings, trusses, rafters, beams, Air Conveyance Systems, Dust Collectors, Ductwork, Lab Fume Hoods, piping, conduit, fire suppression system, lighting, walls, stationary equipment, conveyor belts, etc., should be cleaned in conjunction. The actual cleaning and removing of dust, and particulate build-up, will consist of several cleaning techniques and methods. Cleaning and removal of the grease and particulate build up, should be performed by H.E.P.A. vacuuming, and/or mechanical Wet Wiping, for any surface, to remove any dust and particulate. This portion of cleaning should be performed under containment, to prevent any cross-contamination of other areas and equipment. Mechanical cleaning procedures are based on parameters set by the National Fire Protection Association, (N.F.P.A.), the Fire Protection Research Foundation, the National Air Duct Cleaning Association, (N.A.D.C.A.), the Institute of Inspection, Cleaning and Restoration Certification, (I.I.C.R.C.) standards, the American Biorecovery Association, (A.B.R.A.) standards, the Indoor Air Quality Association, (I.A.Q.A.) standards, OSHA standards, and the I.I.C.R.C. S520 Standard and Reference Guide for Professional Mold Remediation
Not all cleaning vendors are alike in safe cleaning procedures, techniques, quality, and pricing. Be aware of vendors who only clean using dirty rags, brooms, push brooms, compressed air, dustpans, and contaminated cleaning equipment. Facility owners should ask the vendor they hire, to provide a liability insurance, and workmen’s compensation certificate, before and after cleaning pictures, of the complete cleaning, to build a good business relationship. These pictures will document in detail, the quality cleaning the vendor is performing. A certificate of completion, for the combustible dust cleaning, is also required for insurance policies. A clean and safe facility is important for worker morale. Just remember the old saying, "You get what you pay for."
These ideas are helpful basics, in combustible dust cleaning.