Made from hemp seed oil, Hemp Shield Wood Finish and Deck Sealer goes on in a single coat and resists mold and mildew. Manufacturer Fibre Alternatives says that in accelerated weathering tests, the UV-resistant formulation outlasted a number of petroleum-based finishes on the market. It comes in clear and in four colors. The clear finish contains just 9 grams per liter of volatile organic compounds (many times less than other products labeled low-VOC) and none of the 289 hazardous air pollutants listed by the EPA, according to the manufacturer. Hemp Shield, 541.485.1057, hempshield.net.