Ethylene oxide gas kills bacteria (and their endospores), mold, and fungi, and can therefore be used to sterilize substances that would be damaged by sterilizing techniques such as pasteurization that rely on heat. Ethylene oxide sterilization for the preservation of spices was patented in 1938 by the American chemist Lloyd Hall, and it is still used in that role. Additionally, ethylene oxide is widely used to sterilize medical supplies such as bandages, sutures, and surgical implements. The overwhelming majority of medical items are sterilized with ethylene oxide. Preferred methods have been the traditional chamber sterilization method, where a chamber is flooded with a mix of ethylene oxide and other gases which are later aerated, and the more recent gas diffusion method developed in 1967 which relies on a bag that wraps the elements to be sterilized and acts a a mini-chamber in order to minimize gas consumption and make the process economically feasible for small loads. Other names for this alternative method for small loads are: Anprolene method, bag sterilization method or micro-dose sterilization method. Most ethylene oxide, however, is used as an intermediate in the production of other chemicals. The major use of ethylene oxide is in the production of ethylene glycol. The primary end use for ethylene glycol is in the production of polyester polymers. Ethylene glycol is more commonly known for its use as an automotive coolant and antifreeze.