If you are a service, retail, or commercial business (such as a grocery store, restaurant, medical office, or retail store) or other organization such as a non-profit or school, you fall under the purview of municipal and hazardous waste regulations and can generally recycle your excess materials without any specific approvals from the regulatory agencies as long as the materials are not considered hazardous. (For more information, visit DEP's Hazardous Waste page).
In Pennsylvania, Act 101 (Municipal Waste Planning, Recycling, and Waste Reduction Act of July 1988) defines source separable recyclables which can be recycled from municipal sources, schools, non-profits, and service, retail, and commercial businesses. The list includes clear glass, colored glass, aluminum, steel and bimetal cans, high-grade office paper, newsprint, corrugated paper, and plastics. Examples of other materials that could be traded include excess inventory, shipping materials, obsolete or surplus equipment, and computers and electronics.