Below is a list of ULPA Filters manufacturers from Litchfield, Illinois. ULPA filters are ultra-low particulate air filters meaning that they, like HEPA air filters, can remove extremely small particles from the air in order to purify it. ULPA filters are not a specific type of filter, but rather a standard which many types of filters may meet. To qualify as ultra-low particulate, a filter system must be 99.9995% efficient in removing particles 0.12 micrometers or larger such as dust, pollen, mold, microbes and more from a given air stream.