Indoor air quality should be front-and-center in occupational health
Safety professionals are often so focused on the goal of zero accidents at work that they don't always spend as much time as they'd like to (or probably should) on occupational health issues - illnesses that arise in workers based on short and longer term exposure to poor-quality environmental factors.
But that's changing as the issue of indoor air quality (IAQ) becomes more prevalent these days; so too is an area known as indoor environmental quality (IEQ), which refers to the quality of air and the environment in general inside buildings based on pollutant concentrations and conditions that can affect the comfort, health and performance of employees.
The "health" of your factory, store, field office, lab, oil rig or any work facility is affected by factors such as
- air quality
- water quality
- relative humidity
- degree and type of lighting
- sound levels
- amount of leaks
Protect capital equipment as well as employees
Various impetuses drive the process of air filtration. The most important is for human protection, filtering air so that breathing is facilitated. Then there's the reason of protecting your capital equipment, as air filtration helps extend the life of machinery.
Processes like painting need clean air to produce an acceptable finished good. Air cleanliness is mandatory for some processes, and a clean room may be only way to offer that environment.
Air filtration isn't tricky but it takes diligence to keep it up. Air purifiers can have different filter materials, levels of efficiency, sizes and even accessories, all of which play into the decision of what kind of air filtration system to implement.
The holder for the filter must also be considered, as an inefficient holder will let air pass around the filter.
Particulate comes in all shapes and sizes. Bacteria are incredibly small and will fight back, while larger items such as hair and dust are somewhat more predictable.
Mechanical filtration is the most common method of air filtration. It uses a barrier - usually paper, foam, or fiberglass - through which the air must pass before going on its way. The standard furnace filter design, which is the norm for most buildings, is easy to maintain and is reasonably economical. Mechanical filters come in several standard sizes, although custom sizes are also easy to obtain.
Electrostatic filtration purifies the air by using electricity to create a negative ion charge. This charge allows the particles to stick to something, where they can be gathered up and removed. This method of filtration is only useful against larger particles, and the filter must be cleaned regularly.
Air filters are rated by efficiency, which is measured by the particulate downstream of the air filter. The standard furnace filter might be from 60 to 95 percent efficient, while a high-efficiency particulate air filter (HEPA) refers to the ability of a filter to remove 99.7 percent of all particulate down to 0.3 microns in size.
The American Society of Heating, Refrigerating and Air-Conditioning Engineershas created standards for air filtration. (Their acronym, ASHRAE, will often appear when you're researching air filtration and clean buildings.)
Another term you'll likely run across is MERV, which stands for the Minimum Efficiency Reporting Value. The higher the MERV rating, the more efficient the air filter will be.