C:G to T:A transition effect & even considered hydroxylamine to be the most specific mutagen known. Practically, it has been largely surpassed by more potent mutagents such as EMS, ENU, or nitrosoguanidine, but being a very small mutagenic compound with high specificity, it found some specialized uses such as mutation of DNA packed within bacteriophage capsids, & mutation of purified DNA in vitro. An alternative industrial synthesis of paracetamol developed by Hoechst–Celanese involves the conversion of ketone to a ketoxime with hydroxylamine. Some non-chemical uses include removal of hair from animal hides and photographic developing solutions. In the semiconductor industry, hydroxylamine is often a component in the "resist stripper", which removes photoresist after lithography. Biochemistry In biological nitrification, the oxidation of to hydroxylamine is mediated by the ammonia monooxygenase (AMO). Hydroxylamine oxidoreductase (HAO) further oxidizes hydroxylamine to nitrite. Cytochrome P460, an enzyme found in the ammonia-oxidizing bacteria Nitrosomonas europea, can convert hydroxylamine to nitrous oxide, a potent greenhouse gas. Hydroxylamine can also be used to highly selectively cleave asparaginyl-glycine peptide bonds in peptides and proteins. It also bonds to and permanently disables (poisons) heme-containing enzymes. It is used as an irreversible inhibitor of the oxygen-evolving complex of photosynthesis on account of its similar structure to water. Safety and environmental concerns Hydroxylamine may explode on heating. The nature of the explosive hazard is not well understood. At least two factories dealing in hydroxylamine have been destroyed since 1999 with loss of life. It is known, however, that ferrous and ferric iron salts accelerate the decomposition of 50% solutions. Hydroxylamine and its derivatives are more safely handled in the form of salts. It is an irritant to the respiratory tract, skin, eyes, and other mucous membranes. It may be absorbed through the skin, is harmful if swallowed, and is a possible mutagen. See also Amine References Further reading Hydroxylamine Walters, Michael A. and Andrew B. Hoem. "Hydroxylamine." e-Encyclopedia of Reagents for Organic Synthesis. 2001. Schupf Computational Chemistry Lab M. W. Rathke A. A. Millard "Boranes in Functionalization of Olefins to Amines: 3-Pinanamine" Organic Syntheses, Coll. Vol. 6, p. 943; Vol. 58, p. 32. (preparation of hydroxylamine-O-sulfonic acid). External links Calorimetric studies of hydroxylamine decomposition Chemical company BASF info MSDS Deadly detonation of hydroxylamine at Concept Sciences facility Functional groups Inorganic amines Photographic chemicals Rocket fuels Reducing agents