What Actually Goes In the Recycling Cart

Four categories are accepted by very nearly every curbside program in the country, and if you recycle only these you will almost never contaminate a load: corrugated cardboard and paperboard; paper, including mail and office paper; metal food and drink cans, both aluminum and steel; and plastic bottles and jugs — the ones with a neck narrower than the body, marked 1 or 2.

Beyond that core the answer genuinely depends on where you live. Glass is accepted in many programs and excluded from others, because it breaks in the truck, contaminates paper with shards and is heavy to haul relative to its value. Cartons, tubs, clamshells and plastics numbered 3 through 7 vary the same way and for the same reason: whether the facility that receives your load has equipment that can sort them and a buyer who will take them.

If you take one rule from this page, take this one. Plastic bags, film, bubble wrap and anything flexible must not go in the curbside cart, and bagging your recyclables in a trash bag is worse than not recycling them at all.

Sorting facilities separate materials on fast-moving screens and belts. Film plastic wraps around the rotating shafts, and crews have to stop the line and cut it off by hand — this is why the industry calls them "tanglers", along with garden hose, holiday lights, cables and chain. A bagged load has a second problem: sorters cannot see what is inside, so a sealed bag is frequently pulled off the line and sent to landfill unopened, taking genuinely recyclable contents with it.

Plastic film is genuinely recyclable — just not here. Grocery and big-box stores commonly have a front-of-store drop-off bin that takes bags, bread bags, case wrap and air pillows, and that stream goes somewhere that can process it.

Until 2018 a large share of American recyclables was baled and shipped to China. That year China's National Sword policy imposed a contamination limit of 0.5% and stopped accepting most mixed paper and plastics outright. The material had to find domestic buyers or none, and the economics inverted: programs that had been paid for their output began paying to move it.

The consequence at the kerb is that "when in doubt, throw it in" — sometimes called wish-cycling — became actively expensive. Contamination does not just reduce a load's value; above a threshold it can send the entire truckload to landfill. One neighbor's greasy container can travel with your carefully rinsed cans and both end up in the same place.

The corrective is unglamorous: recycle a shorter list, and do it clean. Containers should be empty and dry, with a quick rinse being enough — they do not need washing.

Several household items are widely recycled through other channels and cause real problems in a curbside cart. Batteries, especially lithium-ion from phones, laptops, vapes and power tools, are the dangerous one: crushed in a truck or on a sorting line they can ignite, and they are a leading cause of fires at recycling facilities. They go to a retailer take-back or a household hazardous waste drop-off.

Electronics go to e-waste collection, and in a number of states are banned from landfill altogether. Propane cylinders and aerosol cans with pressure left in them are explosion risks. Clothing and textiles are tanglers. Scrap metal larger than a food can belongs at a scrap yard, which will often pay for it.

The number in the triangle does not mean it is recyclable. The resin identification code says what the plastic is made of, not that anyone will take it. A 5 tub and a 5 bottle can have different answers in the same city because shape, not resin, drives sortability.

The greasy pizza box rule has largely changed. The old advice was to bin any box with grease on it. Many programs now accept pizza boxes, grease and all, on the basis that the small amount of oil does not meaningfully harm the paper stock — the Wall Street Journal-era received wisdom outlived the research. Leftover cheese and crusts still have to come out. As with everything here, your own program's list is the one that counts.