Fluoroelastomers are more expensive than neoprene or nitrile rubber elastomers. THF readily dissolves latex and is typically handled with nitrile or neoprene rubber gloves. Gloves made of nitrile rubber are worn when handling fluoride compounds. Most mats are made of PVC rubber nitrile foam. Material examples are mineral, carbon or nitrile synthetic rubber. An improved version of nitrile butadiene rubber (NBR) is carboxylated nitrile butadiene rubber (XNBR). These gloves are made of latex, vinyl or nitrile. Female condoms are also available, most often made of nitrile, latex or polyurethane. Other materials used to alleviate this are PVC, nitrile, and neoprene. The magnesium then chelates to the hydroxyl group and the oxygen atom of nitrile oxide. The main industrial route to this nitrile is the hydrogenation of acrylonitrile. Organic compounds containing multiple nitrile groups are known as cyanocarbons. An example of a nitrile is CHCN, acetonitrile, also known as methyl cyanide. The nitrile is then converted to an ester. When using acetonitrile as the nitrile, 2-methylpyridine is obtained, which can be dealkylated to pyridine.