Researchers at the U.S. Department of Agriculture have been working to make a cotton production byproduct into bio-based interior wood adhesives. Cottonseed meal is a byproduct left after lint and oil have been extracted from cotton seeds. Generally, cottonseed meal is used as fertilizer or animal feed, but it could become the starting material for alternatives to petroleum-based adhesives. It has already been studied as an environmentally friendly, biodegradable and formaldehyde-free alternative to petroleum-based bonding agents. However, cottonseed meal products have not been commercially developed. A major obstacle is that adhesives made from this material typically have poor water resistance. The Agricultural Research Service has worked to address this by developing a seed meal washing process that improves water resistance in the final adhesive. With further development, bio-based wood adhesives could make use of the more than 1 million tons of cottonseed meal produced each year.