The 160R2 Air Purifier is all metal construction & contains 7 lbs. of activated carbon mix to control chemicals, fumes, odors, gases; and controls particles with an optional HEPA rated at 0.1 micron efficiency. It has performed well in independent lab tests; and is used & recommended by allergists & environmental doctors nationwide. Designed for use by the chemically sensitive, but can be used by anyone that wants clean indoor air. No-odor finishes used where needed, so you can be assured of clean air. Great product for use in schools, hospitals, offices, and homes. Re-fillable or recyclable cartridges make the 160 Series air purifiers the perfect green choice when you want clean air with the least effect to the environment. See our Education page for details.