Entrance Mats, located at the main doors of the building, trap the contaminants from foot traffic. Consider using varying zones of coarseness for entrance mats depending on their proximity to the exterior - the first scraping coarse dirt from soles, the second removing moisture and finer particles, the third absorbing more moisture and drying footwear. This supports improved environmental quality within the office building. Vinyl walk off mats should be avoided if at all possible as the material is known to produce toxins in its manufacturing process.