 Although less dangerous than many other chemical weapons such as sarin, phosgene is still regarded as a viable chemical warfare agent because it is so easy to manufacture when compared to the production requirements of more technically advanced chemical weapons such as the first-generation nerve agent tabun.Upon ultraviolet (UV) radiation in the presence of oxygen, chloroform slowly converts into phosgene by a radical reaction.To suppress this photodegradation, chloroform is often stored in brown-tinted glass containers and with a small percentage of ethanol added.