Why Contamination Ruins Recycling Batches
Launch library · evergreen read
Contamination in recycling refers to non recyclable material, or the wrong type of recyclable, ending up in the recycling stream. A single greasy pizza box mixed with clean paper can weaken an entire bale, since paper fibres are particularly sensitive to oil and food residue during reprocessing.
Soft plastics are a common contamination source in kerbside bins because they tangle in sorting machinery designed for rigid materials, sometimes stopping the whole line while staff clear the jam. Liquids left in containers can also soak into paper and cardboard nearby, ruining otherwise clean material before it even reaches sorting.
Because contamination is assessed at the batch level, a relatively small proportion of incorrect items can be enough to have an entire load rejected by reprocessors and sent to landfill instead, which is why correct sorting by households has such an outsized effect on how much material is genuinely recycled. A single household being careless with sorting can, in aggregate with many others doing the same, meaningfully shift how much of a city's recycling actually gets reprocessed.