Worker Health and Safety
Oil mist nearly always results in oily premises, equipment, and products. Modern metalworking machinery is often controlled by sensitive electronics and production is hampered by unplanned disruptions caused by contaminated controls. Handling equipment and pieces of products coated in a thin film of oil is not an acceptable working practice and definitely not production friendly. Thus, removing oil mist is essential for workplace cleanliness and safety.
Oil mist affects the health of machine operators, disrupts production and settles throughout manufacturing facilities, resulting in dangerous conditions, such as, slippery floors and work surfaces. Nearly all machining operations create oil mist to some extent. Oil mist is the aerosol that is formed when oil is used for cooling or lubricating during the machining of metal and some plastic components. Oil smoke is formed when oil contacts the hot machined surface, vaporizes, and condenses as sub-micron particles.
Prolonged and repeated exposure to oil products can be harmful to health, which means that quality ventilation must be ensured under all working conditions. Oil emulsions normally contain 90-95% water and the remaining is non-soluble oil. The oil mist consists of aerosols from oil or oil/water emulsion. Mineral oil-based metalworking fluids are known as neat cutting oils or straight oils. Emulsions normally contain a number of undisclosed additives.
Oil mist is created when metal working fluids (MWF) become aerosols or mists as a result of heat and/or the machining process itself. There are four types of MWF’s: Straight & soluble oils and synthetic & semi-synthetic fluids . Many of these fluids contain additives. Additives may include, but are not limited to: corrosion inhibitors, emulsifiers, de-foaming agents, stabilizers and sulfur or chlorine based compounds.
Breathing ailments, cancers and skin conditions have been proven to be caused by these mists with prolonged exposures exceeding OSHA thresholds. Nitrosamines, many of which are known carcinogens, can form in stored MWF’s as well as contributing to microbe growth. OSHA has set 5 mg/m3 over an 8-hour time period as it’s max exposure limit value.
Oil Mist Collector Selection
There are several methods of collecting oil mist.
- Ambient oil mist collectors are designed to recirculate the air though several air filtration devices suspended from the ceiling. The media is either electrostatic or polypropylene, designed for the coalescing of mist. Removal efficiencies can be upwards of 95%, however establishing and maintaining an air pattern is critical to its success.
- Machine mounted mist collectors can be placed directly on the machine, allowing the collected coalescing mist to drain back into the machine. They serve only the machine they are mounted to.
- Central oil mist collection systems are ducted from each machine back to a central collector. The central collector will utilize a mechanical separation prior to the media because the volume of mist collected is greater. Each area that is producing oil mist is source captured and sent back to the central collector.
Oil Mist System Design
Whether a central mist collection system or ambient mist collection system the design is as critical as the product selection. A central mist collection system with too much draw will flood the collector with coolant. The duct system needs to be properly sealed using the right duct materials, so it doesn’t leak. Sizing the fan and airflow all play a vital role that should be chosen by someone qualified in industrial ventilation design.
Oil mist ventilation is a complicated science as the oil must be removed from many different source types. Each source type creates a unique challenge and should be designed by a specialist in air quality engineering.
Anyone who produces coolant mist and smoke knows the problems that arise if you don’t effectively capture and filter it. From oil puddles on machinery and floors to the blue haze and odors across the plant, coolant mist and smoke become maintenance issues and safety & health risks. Clean Air mist collectors provide solutions to these issues, offer longer filter life, and better efficiencies.
Once we’ve decided the best mist collection method, we must consider the use. Drilling, lathes and screw machines will generate much less mist than stamping, roll forming and cold headers. Typically, the higher the heat the smaller the particle size and increase in aerosol formation.
Welding fumes are extremely hazardous contaminates to breath and should be captured, and filtered to protect the health of welders.
Welding “smoke” is a mixture of fine particles (fumes) and gases produced from the base materials being welded. Filler materials, coatings, shielding gases, and chemical reactions between material and energy from the arc and the surrounding air are sources of various health hazards. Many of these substances (Chromium VI, Beryllium Oxide, Manganese, Zinc) are extremely toxic and can have both long term and short-term impairments.
Exposure to metal fumes (such as zinc, magnesium, copper and copper oxide) can cause metal fume fever. Symptoms may occur 4 to 12 hours after exposure, and include chills, thirst, fever, muscle ache, chest soreness and nausea. Welding smoke can also irritate the eyes, nose and respiratory tract. Some components of welding fumes, such as cadmium, can be fatal. Gases given off by the welding process can also be extremely dangerous. For example, ultraviolet radiation given off by welding reacts with oxygen and nitrogen in the air to form ozone and nitrogen dioxide. These gases are deadly at high doses and can cause irritation to the nose and throat and serious lung disease.
Studies of welders, flame cutters and burners have shown that welders have an increased risk of chronic lung disease, lung cancer and other respiratory cancers. Welders may experience a variety of respiratory problems, including pulmonary edema (fluid in the lungs), bronchitis, emphysema, coughing, wheezing, shortness of breath and siderosis (a dust-related disease caused by iron oxide dust).
Controlling Welding Hazards
In 2006 the Illinois Supreme Court upheld a decision to award Lawrence Elam 1 million in damages caused by welding fume exposure. OSHA has established permissible exposure limits that must be adhered to or employers are at a liability risk. In addition to exposing employees to welding fumes the Environmental Protection Agency has established Hazardous Air Pollutants (HAP) rules for exhausting contaminates to the outdoors.
Controlling welding fume is a smart business decision to reduce liability from employee lawsuits, OSHA fines or EPA penalties. Clean Air Company can improve working conditions, reduce absenteeism and increase production by providing industrial ventilation for your production facility. Clean Air Company has been providing indoor air quality solutions since 1976 and are experts at handling welding fumes.
- Fume Extraction Arms
- Dust Collectors
- Air Cleaners
- Downdraft Tables
- Fume Guns
- Dust Control Booths
- Fume Hoods
Diesel fuel powered engines are efficient and powerful but have created pollution problems around the globe. Hundreds of studies, starting with the NIOSH Current Intelligence Bulletin 50 published in 1987, have long documented the hazards of diesel exhaust and its suspected carcinogenic effects. The United States EPA, as part of The Clean Air Act, requires manufactures of diesel powered engines to reduce particulate emissions to 2.5 pm starting in 2007. This initiative was created to improve the air quality in metro cities and highly trafficked areas.
The EPA revealed the effects diesel particulate had in urban areas, especially heavily trafficked cities with diesel powered transportation (train, tractors, heavy equipment, generators e.t.c.). These areas showed a correlation in increased cancers, asthma and lung disease that could be attributed to diesel particulate. The World Health Organization has also classified diesel exhaust as a known carcinogen.
Since 2007 diesel powered equipment is outfitted with a diesel particulate filtration (DPF) system to comply with new emission standards. These systems are designed to reduce diesel particulate by filtering the exhaust. Filtration is nothing more than a controlled leak. Larger particulates are captured in the filter while finer particulates and gases pass through. The filters are cleaned by a regeneration process in which filters are heated up to approximately 1,200 F to burn off the particulate that’s accumulated on the filter. These filtration products are good for reducing the particulate levels outdoors to improve the air quality we breathe outside in our communities and cities. But what about indoors?
More studies are being conducted on the hazards of finer diesel particulates that pass through the filter and the elevated concentrations of gases as particulates are burned off the filter. One thing that has not changed is that diesel exhaust is still a known carcinogen and firefighters are one industry that have the highest cancer statistics. These filters were designed to reduce particulate matter we have outdoors, and not to address the issue of indoor air quality problems associated with diesel particulates in firehouses or maintenance and repair shops. Studies prove smaller particulates present a greater risk because of its ability to penetrate the alveoli cavity of the lung. Some argue these filters have created a false sense of security while actually creating greater risk.
Service centers, fleet maintenance repair shops, firehouses and EMS facilities are the most common industries we serve providing products to protect against diesel exhaust exposure. International Mechanical Codes requires source capture systems to connect directly to the tailpipes and exhaust the contaminate directly outdoors in addition to exhaust .75 CFM per square foot of floor space for general ventilation. Some of the most common products we offer for vehicle exhaust applications include;
- Spring operated hose reels
- Motorized hose reel
- Simple exhaust drops
- Emergency Service Exhaust System
Combustible dust has become a primary focus of OSHA and the National Fire Protection Agency (NFPA) due to the recent explosions resulting in catastrophic damage and loss of human life. An explosion in a sugar refinery claimed 14 lives in February of 2008. Since that time OSHA has created the Nation Emphasis Program (NEP) which focuses on industries working with explosive dust. All manufacturing facilities are required to comply with NFPA 652 by September 7th, 2020 to assist manufactures in identifying fire, flash fire and combustible dust hazards.
Having your dust tested for combustibility is part of the dust hazard analysis to provide designers and engineers vital information. Some important information we need as industrial ventilation design specialist includes; minimum ignition energy (MIE) which tells us the minimum electrical energy measured in millijoules to ignite the dust. The MIE is required as static electricity charge generated in a duct system is enough to provide an ignition source. That’s why for wood dust collection systems the duct should be grounded, or pharmaceutical processes should be using anti-static flex hose.
We can also learn the Kst value from a dust explosion severity test which tells us how high the energy (pressure) will rise over a given period of time. This information is important to establish explosion relief panels and chemical suppression requirements. The higher the Kst value, the more energy is generated over a short period. Think in terms of burning wood. When you use smaller pieces of wood to create fire, the wood will burn faster. That’s because there is more surface area of wood to burn. The volume could be the same. Take a 12 inch diameter log, put it on a fire and it burns slowly. Take the same log split it 18 times and place them all on the fire and the intensity increases.
So what dust do you test? Take a sample of the finished product as mixing chemicals will dry them out or create different compounds that are more explosive when batched. This would be a representative sample of what you’re working with. The test results should be shared with your designer so we can incorporate safety features such as abort gates, isolation dampers, chemical suppression equipment, grounded duct systems, rotary air locks and more.
OSHA states almost 40% of all dust explosions occur in the dust collector. As this is where the fuel resides, the cleaning mechanism can create explosion.
Clean Air can provide a compliant dust collection system design that will be granted approval by your local code official. We can include in our system design;
- Spark detection & suppression
- Isolation gates
- Abort gates
- Explosion vent
- Flameless explosion vent
- Chemical suppression
- Fire break shutters