Today I read that shredding paper shortens its fibers and renders it useful for creating toilet paper but not other papers like printer paper. See this link for a reference on shredded paper.
I developed the habit of shredding everything in my office including envelopes. I would then dutifully dump it into a brown paper grocery bag and walk it to the paper recycling bin. The new protocol will be to only shred what is confidential. I’m not even sure that shredded paper does more harm than good. I want to avoid what the NY Times called “aspirational recycling” where you put it in the bin and hope it is either recyclable or some person or machine will remove it if it isn’t. Because of purity standards, contamination can lead to rejection of and landfilling of entire batches of recycled goods.
This article Chinese Paper Contamination says that Chinese standards are now .5 percent contaminated before rejection. So, throwing in food or plastic or pizza boxes is going to render all the recycling as landfill. Perhaps shredded paper will add to that problem. Plastic coated coffee cups, milk containers coated with wax or plastic, juice boxes unfortunately definitely will contaminate the batch.