The technology behind Surround WP was co-developed by Engelhard Corporation (now NovaSource) and the US Department of Agriculture and is referred to as 'particle film' technology. Comprised of specially modified particles of kaolin, a naturally occurring material, Surround WP is mixed in water and sprayed onto crops. Upon drying, a fine white film results. If Surround WP is applied to an edible part of the plant, the film can be washed off at harvest, or spraying can cease early in the season and the deposit weathers off naturally.