9 Materials that can't be recycled

• 1. Concrete

  

  Recycling concrete is extremely limited and energy-intensive. Concrete is often reinforced with steel rebar, mixed with other materials like asphalt, or heavily contaminated with chemicals and debris. It’s bulky and difficult to transport. Concrete production accounts for 8% of global CO₂ emissions, and its poor recyclability worsens the material’s sustainability. Rather than being fully recycled, old concrete is crushed and used as fill or road base. This process is called downcycling, a form of reuse.

• 2. Ceramics and Porcelain

  

  Ceramics include items like mugs, tiles, sinks, and toilets. Ceramics are fired at extremely high temperatures, creating a hard, non-melting structure that typical recycling plants cannot process. They can damage recycling equipment if mixed with glass because they don’t melt at the same temperatures. Some ceramics can be crushed and reused in art projects or as gravel substitute, but large-scale recycling systems for them do not exist.

• 3. Certain Types of Glass (Pyrex, Mirrors, Window Glass)

  

  While glass bottles and jars are recyclable, many types of glass are not. Products like Pyrex, window glass, and mirrors are treated with chemicals or have different melting points making them incompatible with container glass recycling. Mixing them with regular glass can ruin entire batches of recyclable glass. Some facilities repurpose these glasses for construction aggregate but that is about it.

• 4. Greasy Pizza Boxes and Food-Soiled Paper

  

  Cardboard is recyclable unless soaked with grease or food. The oil contaminates the paper making it impossible to process in recycling stream. If facilities accept food contaminated paper, composting is a better option. Consumers are advised to tear off the clean parts of a pizza box and place those in recycling bins.

• 5. Plastic Bags and Film Plastics

  

  Though technically recyclable, most municipal recycling programs do not accept plastic bags. These thin plastics clog sorting machinery and require specialized facilities. Grocery bags, bread bags, bubble wrap, and plastic wrap are common examples.

• 6. Multilayer Packaging (Tetra Pak, Snack Wrappers, Toothpaste Tubes)

  

  This packaging is designed to be light, durable, and preserve shelf life but it’s a recycling nightmare. These items are made from multiple layers of plastic, aluminum, and paper, all fused together. Separating them is not economically viable in most recycling facilities. Less than 10% of multilayer packaging is ever recycled. Most ends up in incinerators or landfills.

• 7. Styrofoam

  

  Styrofoam is everywhere from coffee cups to packing peanuts but it’s rarely recyclable. It’s 95% air, making it extremely bulky and uneconomical to transport or process. Most recycling centers reject it. Styrofoam takes hundreds of years to break down and easily breaks into microplastics that harm marine life.

• 8. Textiles Contaminated with Chemicals or Mold

  

  While clean, dry clothing can often be donated or recycled into rags or insulation. The ones that cannot be recycled include moldy clothes, items soaked in oil, or garments with chemical treatments. They pose health and safety risks and contaminate other recyclables.

• 9. Composite Wood (MDF, Particleboard)

  

  Furniture made from composite materials is common and cheap but nearly impossible to recycle. They are glued together with resins, formaldehyde, and chemicals, making them hazardous to process and unsuitable for reuse. When landfilled or incinerated, they can release toxins into the air or groundwater.