What items are considered contaminants in recycling?

Many items can be considered contaminants. Contamination happens when nonrecyclable items are mixed in with recyclables items, as a result the entire contents of the recycling bin must be thrown in the trash. Innocent looking paper smeared with food or grease cannot be processed with clean paper and can ruin a newly made product if it is not caught before it goes to the factory. Too much contamination is the reason manufacturers reject tons of recyclable paper each year.

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Why can't pizza boxes be recycled?

Pizza boxes are made from corrugated cardboard, however the cardboard becomes soiled with grease, cheese, and other foods once the pizza has been placed in the box. Once soiled, the paper cannot be recycled because the paper fibers will not be able to be separated from the oils during the pulping process. Food is a major source of contamination in commingled recycling.

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What should I do with slightly used paper towels, paper plates, paper napkins, or paper cups?

Although these items are paper, they should be placed in the garbage. Often times these items are soiled with food or other contaminant. Many paper products have a thin plastic lining to give strength to the product and prevent leaking. This plastic lining is considered a contaminant in the pulping process. Please throw paper plates, napkins, and cups in the garbage.

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Should I recycle materials contaminated with food? For example, should I recycle cardboard pizza boxes with food residuals attached to the cardboard? Or should I recycle plastic frozen dinner trays with a small amount of food residuals?

Food or oil contaminated paper is considered a contaminant in single-stream recycling bins. Best examples of this are pizza boxes and donut boxes. Since the paper is mixed with water in a large churner, the oil eventually separates from the paper fibers. The oil does not dissolve in the water, instead it mixes in with the paper. The eventually result is new paper will oil splotches.

Plastics, metal, and glass are recycled using a heat process so usually food or oil contamination is not much of an issue. Sometimes with plastics, depending at what temperature the plastics melts, other types of material including other plastics can be a contaminant.

With the food tray, it isn't so much that the food is a contaminant or a problem during the process. The issue is cleanliness and sanitary conditions. The plastic tray could sit in the recycling bin for a week, for another week it could sit in the recycling yard. Finally, once all the materials are sorted, they are baled or placed in a large bin until enough material has accumulated to send it to a market. So what this boils down to is that your tray with a little bit of food will likely sit around for a least a month. In that time, the food residue will likely grow mold. Also the food will slide off from the plastic tray onto other materials, which then creates a mess.  The best way to handle the food tray is to quickly rinse off the food residue before putting it in the bin.

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I am confused about paper food containers. What is recyclable?

Any food container that has been soiled with food is not recyclable and should be put in the garbage. For example, pizza boxes and other fast food or to-go containers. Paperboard food containers such as cereal boxes, paper egg cartons, and cake mix boxes that are unsoiled are recyclable. Please be sure to remove the plastic liner and shake out extra food crumbs. Frozen food boxes should be placed in the mixed paper bin. Plastic milk, juice carton and soy milk containers can be recycled, however wax coated paper beverage containers should be put in the garbage.

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Can I recycle old photographs and negatives?

No, currently we cannot recycle these materials.

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