Textile waste can be classified as either pre-consumer or post-consumer textile waste. Pre-consumer textile waste is the leftovers or by-products from textile, fibre- or cotton industries. Post-consumer textile waste is the waste of fleece, flannel, corduroy, cotton, nylon, denim, wool, and linen, which have already passed through the consumer market and are recycled and reconstituted into a product for the consumer market once again. Textiles in landfill biodegrade to form methane gas, which is released to the air and is unsuitable for human consumption, which is one of the most effects, that recycling is addressing by diverting textile from landfill. See textile garneting.