Here’s an interesting piece of sustainability news for all of you manufacturers that supply pizza restaurants.

Domino’s and WestRock are encouraging people to toss their empty pizza boxes in the recycling even if they have some grease on them, challenging warnings that only clean boxes can be made into new products.

WestRock, the main corrugated supplier for the global pizza chain, talked with paper mills and studied how dirty used pizza boxes are, concluding that the typical amount of grease and leftover cheese does not affect the quality of a corrugated product containing expected levels of recycled fibers.

Recycling facilities pulled pizza boxes out of their waste streams so WestRock could document grease levels. It would take a higher concentration of grease than you find on a pizza box to interfere with fibers’ bonding ability during the papermaking process, according to WestRock’s study.

Why the confusion over the boxes’ recyclability? Domino’s, which uses 72% recycled content in its boxes, says recycling programs sometimes prohibit pizza boxes to reduce the risk that people will leave uneaten pizza or other food scraps inside, which paper mills prohibit. “Over the years, this has come to be incorrectly interpreted as ‘pizza boxes are not recyclable,’” Domino’s says on its new website to share information about pizza box recycling. 

In areas that ban pizza boxes from recycling streams, Domino’s encourages people to call their municipalities to ask them to add the boxes to their collection. About 75% of the U.S. population has recycling programs available for pizza boxes, according to WestRock research estimates.

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