ProWood Micro wood is treated with Osmose’s MicroPro, a preservative that has earned Scientific Certification Systems’ Environmentally Preferable Product certification. MicroPro copper wood pre-servative doesn’t need organic solvents to dissolve its copper components, says the maker, instead using a micronizing technique that grinds particles to a size that lets them penetrate the wood as a solid; wood products treated with MicroPro release 90% to 99% less copper into water or soil. 800.598.9663.