Recycling is the collection and processing of discarded materials into raw materials or new products. It is part of waste management and differs from reuse, which keeps products or components in service without substantially reprocessing their materials. Recycling connects waste collection with manufacturing: placing an item in a collection bin is only the beginning, not evidence that its material has been successfully recovered. (epa.gov)
Scope and classification
Recycling handles household packaging, commercial waste, manufacturing residues, and selected construction materials. Common streams include paper, glass, metals, plastics, textiles, and organic matter. Different materials require different collection arrangements and treatment processes; a municipal collection program therefore does not necessarily accept everything that can technically be recycled. (epa.gov)
The waste hierarchy generally places waste prevention and reuse above recycling, with energy recovery and disposal below it. This ordering reflects the value of avoiding waste before investing resources in treating it, although the preferable treatment depends on the material and circumstances. composting is commonly included alongside recycling as a route for recovering organic waste. Recycling supports a circular economy, but it is only one element of that broader approach to retaining products and resources in use. (epa.gov)
Collection, sorting, and manufacture
Collection systems include curbside pickup, drop-off centers, and deposit-refund systems. Collected recyclables pass through sorting and preparation before manufacturers can use them. Their sale does not differ fundamentally from other raw-material transactions: prices depend on quality and supply and demand. A functioning system requires both collection capacity and buyers for its outputs. (epa.gov)
A materials recovery facility separates mixed materials into commercially usable streams. Equipment may include screens, magnets for ferrous metals, eddy-current separators for nonferrous metals, and optical sorting systems. Manual sorting supplements these operations. Facilities handling construction and demolition debris use combinations of these methods suited to larger and more heterogeneous materials. (nepis.epa.gov)
Contamination affects the quality and usability of recovered materials. Food residues, incompatible materials, and incorrectly sorted items complicate processing. A plastic resin identification code identifies the material type; it does not establish that a local program accepts the item. Technical recyclability and availability of an operating collection-and-processing system are distinct questions. (epa.gov)
Material-specific processes
Paper and cardboard. Recycling recovers fibers for further papermaking. Processing separates usable fiber from contaminants and may remove printing inks. Recovered paper can replace some virgin fiber, but processing losses and changes in fiber properties limit repeated recovery. The environmental comparison also depends on manufacturing processes and the treatment that would otherwise have been used. (nepis.epa.gov)
Metals and glass. Metals are recovered through separation and metallurgical processing. Their composition and purity affect the products they can enter. Glass recycling commonly uses recovered container glass as furnace feedstock; suitability depends on the intended application and contamination. Recycling aluminum avoids much of the resource-intensive primary production pathway, while benefits for glass depend partly on furnace inputs and transport. (nepis.epa.gov)
Plastics. Mechanical recycling sorts, cleans, grinds, and typically melts plastics for manufacture into new products. Different polymers and contaminants can affect processing and output quality. Solvent-based purification dissolves a polymer to separate impurities, whereas chemical routes break it into smaller molecules. For some polyester plastics, processes include glycolysis, methanolysis, and enzymatic hydrolysis. These pathways differ in feedstock requirements, costs, yields, and environmental effects. (nlr.gov)
Organic materials. Composting processes organic waste into an amendment that can improve soil. Unlike remelting a metal or plastic, it uses biological transformation to recover useful material from food scraps and other suitable organic inputs. (epa.gov)
Environmental performance and limitations
Recycling can reduce extraction of virgin resources, demand for energy, and waste sent to disposal. Its environmental value nevertheless depends on what recovered material replaces and on the burdens of collection and processing. Life-cycle assessment compares these stages rather than treating diversion from disposal as a complete measure of benefit. EPA’s Waste Reduction Model evaluates energy use and greenhouse gas emissions across alternative material-management pathways. (epa.gov)
No single plastic-recycling technology performs best under every condition. A 2023 national-laboratory comparison found mechanical recycling generally favorable across the economic and environmental metrics examined, but identified limitations in output quality. Improved sorting and pretreatment can strengthen its performance; chemical processing offers other possibilities but involves different trade-offs. (nlr.gov)
Economics and policy
Recycling depends on reliable infrastructure, consistent feedstock quality, and demand for secondary materials. Variable commodity prices and weak end markets can undermine the economics of collection and processing even where the technology exists. (epa.gov)
Extended producer responsibility assigns producers financial or operational responsibility for products at the post-consumer stage. Such systems can finance collection and treatment and provide incentives for product design. Other policy instruments include recycling targets, recycled-content requirements, and disposal charges. Their roles differ: some support collection, others influence manufacturing demand or the relative cost of disposal. (oecd.org)
Measurement
Collection rates, recycling rates, and recycled content measure different stages of material use. Collection alone can overstate recovery because sorting rejects and processing residues still require treatment. The OECD estimated that, globally in 2019, 55 million tonnes of plastic waste were collected for recycling, but 22 million tonnes became recycling residues. After losses, approximately 9% of the 353 million tonnes of plastic waste generated that year was ultimately recycled. These figures describe plastics in that year, not all materials or present-day recycling performance. (oecd.org)