Preventing contamination

A guide to the problem with putting the wrong materials in your kerbside recycling bins, and the issues it can cause.

Contamination is basically the wrong materials in the wrong bin. Putting the wrong items in the wrong bin causes recyclable material to become contaminated, and can lead to it being rejected by our re-processor, and ultimately ending up in landfill. This is why we try to ensure that everybody understands how the kerbside collection scheme works and how to use it properly.

Which materials are classified as contamination?

Contamination can be anything from small items such as sweet wrappers, bottle tops, or glass bottles, to larger items items such as bags of general waste, nappies, or packaging covered in food waste. Information on what can, and can't be recycled in your kerbside recycling bins can be found on the blue-lidded and brown-lidded bin pages.

Why is contamination a problem?

Once your wheelie bin has been collected, the materials are then passed to our re-processors to be sorted for recycling or composted. Materials in your blue-lidded bin are hand-sorted into their specific type. As this work is predominately carried out by hand, items such as glass can pose a health and safety risk to workers.

Contaminants such as hidden bags of general waste, or food contaminated cardboard can spoil the other recyclates in the load. When your wheelie bin is emptied into the lorry, a compactor squashes the contents to make room in the back of the lorry for more recyclable waste. The process of squashing can cause bags of general waste to spilt open and cover surrounding materials. This can be particularly bad if the offending bag contains wastes such as dog mess, nappies, or food. If you place food contaminated cardboard/packaging into your recycling bin without first quickly rinsing it, other items in the load such as clean paper and cardboard can be spoiled, and render them non-recyclable.

If you place such materials as plastics, metals or glass into your food and garden waste (brown-lidded) bin, this will impact the ability to compost that load, and these contaminant materials that could have been recycled elsewhere will be landfilled. If you place materials such as soil or stones into your brown-lidded bin, then this too is treated as contamination. These materials are classed as "inert", which means they cannot break down any further. If they are passed through the composting process, they can significantly slow down, and even stop other materials from being composted.

What can I do to prevent contamination?

If you are unsure about which materials you can recycle at the kerbside, please visit the blue-lidded and brown-lidded bin pages for more information and clarification.

Always try to give your blue-lidded bin materials a quick rinse before placing them into your recycling bin. This will lower the risk of food or drinks contaminating other materials in your bin. More importantly, a quick rinse can stop your recycling bin from becoming smelly, or dirty.

Where possible, try to present your bin on the morning of collection rather than the night before. A common contamination complaint from householders is that people passing by are placing the wrong materials into their recycling bins, resulting in bins not being uplifted by crews due to visible contamination.

Contact details

Waste and recycling

Pullar House, 35 Kinnoull Street, Perth, PH1 5GD
Tel 01738 476476