Fluorine, odour

M.F.A. is practically odourless. When four of us were exposed to a concentration of 1/1,000,000 in a 10 cu.m, chamber, we were unable to detect the compound. Even at 1 /100,000 (30 sec. for reasons of safety) the compound was found to possess only a faint fruit-like odour indistinguishable from that of many harmless esters not containing fluorine. 

Elemental fluorine, which is a member of the halogen family, is a pale yellow-green, irritating gas with a sharp odour and atomic mass of 18.998. Fluorine is chemically most reactive of all the elements and does not therefore occur naturally in the free state. In combination it comprises 0.065% of the earth s crust, being the 13th element in abundance [1], and is an inevitable part of the biosphere and human life. The term fluorine is, in this report, used to denote the element in any of its forms and fluoride to denote free inorganic fluoride to which a fluoride ion-selective electrode (ISE) responds. 

Halothane was introduced into clinical practice in 1956. It was not the first fluorinated anaesthetic— fluoroxene (Fluoromar) holds that distinction—but it was the first to achieve widespread acceptability. Halothane is a fluorinated alkane 1-bromo, 1-chloro -2,2,2-trifluoroethane (Figure 3.2). It has a characteristic odour, similar to chloroform, and requires a stabiliser, thymol (0.01%), to prevent degradation by light. Halothane has a blood/gas partition coefficient of 2.4 able 3.2) but its lack of irritant qualities makes possible the use of relatively high inspired concentrations (2-4%). For that reason, inhalation induction is characteristically smooth and rapid. Compared to sevoflurane, and possibly isoflurane, recovery from halothane anaesthesia is delayed. 

Fluorine at ordinary temp, is a greenish-yellow gas when viewed in layers a metre thick the colour is paler and more yellow than that of chlorine. The liquid gas is canary-yellow the solid is pale yellow or white. Moissan s gas has an intensely irritating smell said to recall the odour of hypochlorous acid or of nitrogen peroxide. Even a small trace of gas in the atm. acts quickly on the eyes and the mucous membranes and, in contact with the skin, it causes severe burns, and rapidly destroys the tissues. If but a slight amount is present, its smell is not... 

Tellurium Hexafluoride, TeFe, appears to be more stable than tellurium tetrafluoride. It has been obtained by the action of fluorine on tellurium at —78° C. The resulting colourless crystalline solid vaporises on allowing the temperature to rise. The solidified substance melts at —36° C. and boils at —35-5° C., the critical temperature being 83° C. The vapour density is 119-5, agreeing with the formula TeFe. The gas has an unpleasant odour, recalling ozone and tellurium hydride. Water only slowly decomposes the gas, which does not attack glass. 

For example, by employing a temperature of 250° C. and a rapid stream of fluorine, a very reactive osmium preparation was found to yield a high percentage of Osmium Oetafluoride, OsF8. This, being the most volatile of the products, is collected in a vessel cooled in a mixture of solid carbon dioxide and alcohol, under which conditions it yields a yellow, solid sublimate. It melts at 34-5° C. to a yellowish red liquid. Its vapour is colourless, has a characteristic odour and metallic taste it attacks the mucous membranes of the nose and eyes. In moist air the vapour yields a white cloud. 

Recently, some fluorinated members of this group have been prepared, such as fluoroacetophenone, a brown liquid with a pungent odour, which boils at 98° C. at 8 mm. pressure. It is described as having lachrymatory properties, but the magnitude of these is not reported. 

Trifluoronitroso methane, obtained by the action of fluorine on silver cyanide in the presence of silver nitrate, is a bright blue gas, fairly stable chemically. It melts at — 150° C., boils at — 80° C. and has an unpleasant odour. 

Drinking Varying turbidity which determines treatment Chlorination (fluorination) Transparency, taste, odour, hardness, bacteriological activity (Fe, Mn)... 

Fluorine is an almost colourless gas. In dense concentrations and in the liquid state it is seen to have a pale greenish yellow colour. Fluorine or its mixtures with N2 or Ar are transported in steel bottles, bundles of steel bottles and tube trailers. Fluorine has a characteristic odour, similar to a mixture of ozone and chlorine. As the most reactive of all the elements and the most powerful known oxidizing agent, fluorine is able to react with almost all elements and compounds, with the exception of lighter noble gases and fluorides of the highest valence. These reactions occur very often even at room temperature, sometimes explosively and often accompanied by combustion. [28, 29, 30]. 

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