The non-polar nature of limonene means that it has an affinity for petroleum based greases and it has been used as an industrial cleaner for more than thirty years. One advantage is that limonene is not toxic and is replacing the use of solvents like methyl ethyl ketone (MEK), xylene (dimethylbenzene) and chlorofluorocarbons (CFCs), the use of which has been banned. Limonene also has the advantage of being biodegradable and can rapidly break down into carbon dioxide and water. Another benefit of limonene is that it is obtained from a renewable resource. A by-product of the citrus juicing process is the oil found in the peel of the fruit. Limonene can be distilled from this oil for both technical and food based uses.