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STI Medical Waste Treatment Process

Steps	Actions
Step 1	Regulated Medical Waste, Infectious Waste/ Clinical Waste (including animal bedding), Import Waste, and HIPPA documentation is loaded into the system in bags, boxes, sharps containers, trace carts, or is automatically fed by a cart dumper.
Step 2	Air is drawn from around the feed hopper area through HEPA filters, to capture potential airborne pathogens that could be released during the waste dumping and shredding process.
Step 3	Containerized waste drops into a heavy duty shredder.
Step 4	Shredded waste enters the steam auger chamber where low pressure steam is injected through multiple ports immediately bringing all material to proper treatment conditions.
Step 5	The distal portion of the STI System steam jacket provides continued heating of the waste, which drives off water vapor absorbed by the direct injection steam treatment function.
Step 6	The Low Pressure Flash-Off Chamber allows moisture to vent to the atmosphere. The residue exits the end of the conveyor (auger) into a compactor and may be disposed of as municipal waste.

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The STI System addresses every one of these issues:

• The inclusion of a negative air pressure and H.E.P.A. filter system addresses the issue of potential release of airborne pathogens during the integral shredding process.
• The use of a cleanser acts as a deodorant for the waste stream. The chemical used (sodium hypochlorite) has been approved by the U.S. EPA FIFRA Administration specifically for use in WR²'s STI machinery.
• Shredding destroys the waste containers, bags, boxes, sharps, maximizing waste surface area, thus assuring that ALL the waste is adequately exposed to the steam.  It addresses the issue of subsequent "unusability" of sharps.
• Accurate validation testing is achieved by introducing a "carrier" containing challenge spores after the shredder so that the spores actually travel with the waste during the treatment process.
• Shredding creates a relatively "homogeneous" waste stream with a very high surface area characteristic. The homogeneity of the shredded waste stream translates into the ability to select thermal treatment temperature and retention time parameters that are valid and create a verifiable short process time for production.
• Direct steam impingement in a rotating auger specifically designed to mix the waste creates paths for steam permeation, which rapidly raises the waste stream's temperature into the proper operating range.
• Operating temperatures are deliberately set below the threshold temperature of the volatilization of plastics, thereby avoiding problems associated with V.O.C. emissions.
• The STI System integration of shredding and direct steam treatment ensures maximum exposure of all contaminated waste surfaces to the proper treatment conditions. Treatment blockages or cold spots associated with other methods leading to the potential of discharging portions of untreated waste are eliminated by WR²'s design.

The STI Medical Waste System incorporates a steam jacketed waste dehydration feature, prior to discharge which drives off water vapor absorbed by the direct steam treatment injection function. Combining these features with heavy duty construction and superior components creates a system that has a long life with a low operating and maintenance cost profile.