RF welding is fast and relatively easy to perform, produces a limited degradation of the polymer even welding thick layers, does not create fumes, requires a moderate amount of energy and can produce water-, air-, and bacteria-proof welds. Welding parameters are welding power, (heating and cooling) time and pressure, while temperature is generally not controlled directly. Auxiliary materials can also be used to solve some welding problems. This type of welding is used to connect polymer films used in a variety of industries where a strong consistent leak-proof seal is required. In the fabrics industry, RF is most often used to weld PVC and polyurethane (PU) coated fabrics. Other materials commonly welded using this technology are nylon, PET, PEVA, EVA and some ABS plastics. Exercise caution when welding urethane as it has been known to give off cyanide gasses when melting.