What Actually Gets Recycled, and What Does Not

The codes run from one to seven. One is PET, used for clear drink bottles. Two is HDPE, used for milk jugs and detergent bottles. Three is PVC. Four is LDPE, the flexible film in bags and squeeze bottles. Five is polypropylene, common in tubs, caps and food containers. Six is polystyrene, including foam. Seven is a catch-all for everything else, including mixed and multilayer materials.

The symbol tells a sorting facility what a piece of plastic is. That is genuinely useful information at a materials recovery facility, which is who it was designed for.

The problem is the arrows. Wrapping a material identifier in a recycling symbol invited a reading it was never meant to carry, and the result is decades of people confidently putting non-recyclable items into a recycling bin because they saw a triangle.

The honest test is not the number. It is whether your local programme lists that item as accepted.

Recycling only happens if someone buys the output. That single fact explains most of what otherwise looks like inconsistency between programmes.

PET bottles and HDPE containers are collected in large, clean, uniform volumes. That makes them cheap to sort and valuable to buy, and there are established end uses for both. If you put a rinsed drink bottle or a milk jug in a kerbside bin in a programme that accepts them, it has a genuine chance of becoming something.

Polypropylene, code five, has been growing in acceptance but remains inconsistent between programmes. Codes three, six and seven are rarely accepted in residential collection anywhere.

Shape matters as much as resin. Rigid containers sort well. Film and flexible plastic tangles in the machinery at sorting facilities and is excluded from most kerbside programmes for that reason, even though the underlying polymer is technically recyclable. Grocery bags and similar film usually need a dedicated store drop-off if one exists.

Most people who wishcycle are trying to do the right thing, which is exactly why the behaviour is so persistent.

The costs are concrete. A greasy pizza box or a container with food residue can spoil surrounding paper. A plastic bag wraps around the rotating shafts of sorting equipment and has to be cut out by hand. Items that do not belong have to be picked off the line by a person.

Beyond the operational cost, contamination lowers the value of the recovered bale, and at low enough quality there is no buyer. That is when a load ends up landfilled despite having been sorted at the kerb.

The rule that follows is uncomfortable but correct: when in doubt, throw it out. A single wrong item in the general waste stream is a much smaller problem than the same item contaminating a recycling load.

The better version of the rule is to look it up once. Local programmes publish their accepted-materials list, and ten minutes spent reading it settles most of the recurring questions permanently.

Two failure modes exist here and people tend toward one or the other.

The first is not rinsing at all. A container with sauce or dairy residue sitting in a bin for a week in a subtropical climate contaminates whatever it touches, and it makes the sorting line unpleasant for the people working it.

The second is over-rinsing: scrubbing containers to a dishwasher standard, using a meaningful amount of hot water for each one. That trades a water and energy cost for a marginal quality gain.

Empty it, give it a quick rinse with cold water, let it drain. Lids are worth checking separately, because whether caps should stay on or come off varies by programme and by container type.

Cardboard follows the same principle. Flattened and dry is good. Wet or grease-soaked is a contaminant, because the fibres cannot be recovered once they are saturated with oil.

Compostable packaging is a genuine improvement in the right system and close to useless outside it, which makes it one of the more confusing categories a consumer encounters.

The certification behind a compostable claim almost always refers to industrial composting conditions. If your area has no industrial composting collection, a certified compostable cup has nowhere correct to go.

It should not go in plastic recycling, where it is a contaminant. In landfill it behaves much like anything else in an oxygen-poor environment: slowly. In the ocean it persists.

Bioplastic is a separate claim again, describing what the material was made from rather than how it breaks down. A plant-derived plastic can be chemically identical to a petroleum-derived one and just as persistent.

The practical takeaway is to check whether the disposal route the label assumes actually exists where you live. If it does not, the label describes a hypothetical.

Recycling gets disproportionate attention because it is the step that involves a bin and a visible weekly ritual. The two steps before it are quieter and matter more.

Reduction is the highest-leverage action available and the least visible. An item never manufactured has no collection cost, no sorting cost, no reprocessing cost, and no chance of ending up in a storm drain.

Reuse extends the working life of something already made, spreading its manufacturing footprint over more use. A refillable bottle carried for two years replaces a large number of single-use ones and eliminates every one of them as a potential piece of marine debris.

Recycling remains worth doing properly. It genuinely reduces demand for virgin material where markets exist, and doing it correctly costs nothing but attention.

It is just not the answer to plastic in the ocean. Material that reaches a shoreline was never in the recycling system to begin with, and once it has weathered on a beach it is contaminated with sand and salt and generally not recoverable. That is why interception, at a storm drain or at a waterline, sits alongside recycling rather than downstream of it.