Carbon dioxide solvents such as organochlorides. It is used by some dry cleaners for this reason (see green chemistry). It is used in the preparation of some aerogels because of the properties of supercritical carbon dioxide. Plants require carbon dioxide to conduct photosynthesis. The atmospheres of greenhouses may (if of large size, must) be enriched with additional to sustain and increase the rate of plant growth. At very high concentrations (100 times atmospheric concentration, or greater), carbon dioxide can be toxic to animal life, so raising the concentration to 10,000 ppm (1%) or higher for several hours will eliminate pests such as
Carbon dioxide laser as 5,000° C, producing bright thermal radiation. The common plastic poly (methyl methacrylate) (PMMA) absorbs IR light in the 2.8–25 µm wavelength band, so CO lasers have been used in recent years for fabricating microfluidic devices from it, with channel widths of a few hundred micrometers. Because the atmosphere is quite transparent to infrared light, CO lasers are also used for military rangefinding using LIDAR techniques. CO lasers are used in spectroscopy and the Silex process to enrich uranium. The Soviet Polyus was designed to use a megawatt carbon-dioxide laser as an in-orbit weapon to destroy SDI satellites. Carbon dioxide