Use an approved compressor oil from a closed, sealed container. When adding refrigerant oil, ensure that the transfer device and container is clean and dry in order to minimize the possibility of contamination. Refrigerant oil is moisture-free and will readily absorb moisture from the air. Do not open the oil container until the service procedure requires oil. Immediately cap the oil after use. Always store compressor oil in a closed, sealed container. Compressor oil that is left in an open or an improperly sealed containers will absorb moisture. Do not reuse oil that has been removed from the refrigeration system. Dispose of used oil properly, according to local regulations.