Fugitive Dust Control
Industrial Vacuums Reduce Respiratory, Explosion Hazards

The sweeping or blowing of fugitive dust during housekeeping is widely discouraged by OSHA and the NFPA for nearly all industries, for good reason, too. Seemingly benign dusts can create an assortment of hazards, including suspended particles that can lead to respiratory ailments, eye injury, slip hazards and ergonomic injuries.

Certainly, the most dramatic hazard associated with dust is secondary explosion. So dramatic that it captured the attention of Congress, which led it to direct OSHA to “issue an interim combustible dust rule and an amendment to the Hazard Communication Standard (HCS).”

With over 4,900 violations associated with OSHA’s Combustible Dust National Emphasis Program (NEP), the recent news about it leveling fines at four companies ranging from $63,000 to $137,000, it should now be clear that OSHA is serious about enforcing current standards.

In response to OSHA’s NEP, many facility and safety managers have revamped their housekeeping practices and added industrial vacuum cleaners approved for use in Class II Div II areas to mitigate the possibility of secondary explosions caused by fugitive dust.

However, of the more than 1,000 inspections that OSHA has completed, only 18 to 22 percent of the facilities were in compliance with OSHA requirements.

“It can sometimes be tough for facilities,” says David Kennedy, general manager for VAC-U-MAX’s vacuum cleaning division. “They may have gotten approval from the authority having jurisdiction (AHJ) but OSHA can still come in and fine them if they deem that the facility doesn’t meet combustible dust standards.”

Although it can be argued that current OSHA standards are ambiguous, hence OSHA’s proposed rulemaking, the standards, however daunting to sift through, are clearly noted in OSHA’s Safety and Health Information Bulletin entitled “Combustible Dust in Industry: Preventing and Mitigating the Effects of Fire and Explosions,” which was first issued five years ago.

According to the report, housekeeping ranked second in citations under the NEP “with respect to combustible dust related hazards.” In addition to accumulations of combustible dust being prevalent among the violations, blowing dust with an air compressor, and not using electrical equipment that was designed for hazardous (classified) locations were also among the top violations related to combustible dust related hazards.

“There is no single standard, or one vacuum cleaner that can meet the requirements for all combustible dust,” says Kennedy. “Companies really need someone who has intimate knowledge of how chemicals react in certain environments and is experienced in NFPA standards to help them choose the right Class II Div 2 vacuum cleaner.”

Compliance

Although, OSHA’s 1910.22 has no specific wording that address fugitive dust, the Bulletin states, “housekeeping standard at 29 CFR 1910.22 not only applies to typical housekeeping hazards but also applies to dust accumulation hazards.”

There are other OSHA standards, such as “Dust Control Handbook For Minerals Processing,” OSHA’s “Grain Handling Facilities Standard,” and the Mine Safety and Health Act regulations for coal mines that do address fugitive dust, suggesting that operations “eliminate the use of compressed air jets to clean accumulated dust from equipment or clothing and substitute a vacuum cleaning system to clean spills and dust accumulations.” It adds, “avoid brooms and shovels.”

In addition, most NFPA standards recommend vacuum cleaning as the preferred first defense method for controlling fugitive dust. NFPA 654 8.2.2.2 states, “vigorous sweeping or blowing down with steam or compressed air produces dust clouds and shall be permitted only where the following requirement has been met: (1) Area and equipment shall be vacuumed prior to blow-down.”

The standard goes on to say, “vigorous sweeping or blowing down with steam or compressed air should only take place after the area or equipment has been vacuumed due to the creation of dust clouds by the other methods.”

With so many standards advocating the use of vacuum cleaners in the housekeeping process, one might be surprised to find so few being used in facilities. Especially since the first air-operated industrial vacuum cleaner was developed in 1954 specifically to prevent dust explosions in textile mills.

However, when most people think of vacuum cleaners in an industrial setting, they often think of shop-type vacuums that they have in their garages. Sometimes facilities have attempted to employ those types of vacs and find that they not only create sparking hazards, but are ineffective at sucking up fine dust particles or heavy materials, and often create their own dust clouds when operating.

Air powered industrial vacuum cleaners that meet NFPA 70 requirements for grounding and bonding, also meet the definition of an “intrinsically-safe system” because they do not use electricity and do not generate any heat from operation.

Implementing industrial vacuum cleaners is one of the most cost effective methods to handle fugitive dust and avoid some of the most cited OSHA violations regarding combustible dust and to protect facilities from catastrophic dust explosions.

Dust Explosions

Recent dust explosions, serve as a reminder that secondary dust explosions are more destructive than primary explosions. The reason for this is increased concentrations of dispersed combustible dust that is activated from the initial explosion.

Beyond creating dust clouds that, have the potential to ignite, sweeping or blowing dust during housekeeping routines causes powders to become suspended and settle in hard to reach areas to reach, including beams and walls or areas that are hidden behind equipment or in very small spaces that are difficult to reach during daily housekeeping routines

The accumulation of combustible dust in areas such as this are among some of the most cited violations by OSHA. The use of industrial vacuum cleaners designed for use in Class II Div II environments, not only remove dust particles as small as one micron, but when used regularly in housekeeping routines minimizes the amount of dust that can collect in hard to reach areas. Reducing the amount of dust that is suspended in the air leads to lower housekeeping costs because fewer man-hours are required for the task.

“The business of working with powders is fascinating,” says Kennedy. “We work with so many different chemicals that have such wide-ranging reactions—it never gets boring. Some chemicals don’t get wet with water; in fact, they can even become more flammable when exposed to water. We are working on an application right now that is a waste product of three different chemicals. There is no name for this chemical, but we are helping our client deal with the explosive nature of this waste.”

Respiratory and Other Hazards

Reducing the amount of combustible powder that is suspended in the air, by using industrial vacuum cleaners, not only mitigates the possibility for dust explosions, but can also lead to a better respiratory environment for workers, reduce slip hazards and even prevent back injuries caused by cleaning heavy dusts.

“Some powders, such as silica, when blown with air compressors have the ability to hang in the air for days,” said Kennedy. “Others, such as graphite, are slippery; and, some are very heavy, like cement that can weigh 50 to 70 pounds per cubic foot and can cause back injuries when sweeping them.”

When dusts hang in the air for longer periods, they can exacerbate respiratory threats. Silica exposure can lead to silicosis, a lung disease caused by continued inhalation of siliceous minerals that are prevalent in glass, brick, cement, asphalt, ceramic, and metal fabrication industries where sand is used as a component or for blasting, as well as in tunneling operations.

“Silica, of course, is only one of the powders that pose respiratory threats to workers,” says Kennedy. “To combat those, we can provide a second HEPA filter rated 99.97 percent on particle size to 0.3 microns.” Fugitive dust and debris is a house keeping issue that plagues most industries. Working with a vacuum cleaner manufacturer that is intimate with chemical characteristics produces the best outcome for facilities combating fugitive dust.

Most vacuum cleaning solutions that are employed to combat fugitive dust aren’t considered capital expenditures and can be purchased as pre-engineered solutions designed for specific powder characteristics, quickly bringing facilities into compliance not only for explosion hazards, but for other dust and debris related housekeeping issues that pose respiratory, slip, and ergonomic hazards.

To assist companies in understanding OSHA requirements, VAC-U-MAX has developed a website, www.combustibledustvacs. com, dedicated to combustible dust hazards, including OSHA documents referencing the hazards and compliance. VAC-U-MAX, a manufacturer of industrial vacuum cleaning systems for production lines and other dust-intensive areas, developed the first air-operated industrial vacuum cleaner to prevent dust explosions. FSM