Phosgene odour

Benzoyl chloride C6H5COCI Colourless, fuming, corrosive liquid with a strong odour Combustible flash point 72°C Generates phosgene gas when heated Reacts strongly with water or water vapour, producing heat and toxic/corrosive fumes Use of water must be considered carefully... 

Colourless, fuming, corrosive liquid with a strong odour Combustible flash point 72°C Generates phosgene gas when heated... 

Phosgene needed is made by reaction of chlorine and carbon-monoxide at 200°C in presence of charcoal. It is a poisonous gas having unpleasant odour. 

Notes. (I) Keten is a poisonous gas having a toxicity comparable with phosgene leaks from the apparatus, which must be contained in a fume cupboard, are recognised by a pungent odour resembling acetic anhydride. For this reason it is customary to attach a second receiver flask containing a compound which readily reacts with keten, e.g. aniline, to the other arm of the three-way stopcock. In this way when the reaction in the main flask is complete the keten gas may be diverted to the second receiver flask while the apparatus is switched off and allowed to cool. Escape to the atmosphere of keten is thereby avoided. 

At ordinary temperatures phosgene is a colourless gas with a characteristic odour described as that of mouldy hay. On cooling to below 8° C. it becomes a colourless, mobile liquid boiling at 8-2° C. It solidifies at — 118° C. to a white crystalline mass. The technical product is, however, pale yellow or orange owing to the presence of coloured impurities, such as chlorine, ferric chloride, etc. 

This is a colourless liquid with an odour of phosgene and b.p. 158-5° to 159-5° C. Density 1-64 at 20° C. It is stable to cold water, but on heating with water it decomposes to form hexachloroethane, hydrochloric acid, carbon monoxide and carbon dioxide. With an aqueous solution of aniline it forms diphenyl urea. 

Further chlorination causes the substitution of all the six hydrogen atoms by chlorine and hexachloromethyl ether is obtained. This is a liquid with an odour of phosgene, having a boiling point of 98° C., at which temperature it partially decomposes into phosgene and carbon tetrachloride. Density 1-538 at 18° C. 

Colourless mobile liquid with an irritating odour slightly reminiscent of phosgene. It is also known as " Diphosgene. ... 

White crystals, melting at 78° to 79° C. It has an odour of phosgene and boils at ordinary pressure at 205° to 206° C. with partial decomposition. S.G. about 2. Soluble in benzene, carbon tetrachloride, ether, etc. 

Phosgene cannot be detected by smell (see Section 3.1.3) at the generally accepted occupational exposure limit of 0.1 p.p.m. [43,1703]. Although the sense of smell undoubtedly acts as a natural safety detection warning system, the accepted odour threshold is approximately ten times the TLV-TWA. The odour safety factor (TLV/odour threshold) has been calculated as 0.11, and the material has been assigned an odour safety elassification "E" to suggest that less than 10% of attentive persons can detect the gas at a concentration corresponding to its TLV [43]. 

To rely upon the detection of phosgene by its odour would, therefore, be hygienically undesirable. Fortunately, safe and reliable methods for its detection are available and, in particular, the extent of exposure is conveniently provided [145] by special detector badges... 

Personnel engaged in the handling of phosgene should be trained to recognize its odour... 

When pure 1,1-dichloroethene (vinylidene chloride) is exposed to oxygen, it develops a sharp odour as a result of the formation of a peroxide, which decomposes to phosgene and formaldehyde [1360a]. The peroxide precursor has been formulated as having either a cyclic or a polymeric structure ... 

At room temperature and atmospheric pressure, carbonyl difluoride is a colourless gas which is condensable to give a colourless liquid (boiling at -84.6 C at normal atmospheric pressure [1580]) or a white solid (melting at -111.3 C [1580]). It has a pungent odour and, unlike phosgene, is rapidly hydrolysed even in ambient air. The relative molecular mass of COFj is 66.0072, and the density of the gas is estimated to be 2.744 g dm 3 [1764]. The gas is heavier than air, with a specific gravity of 2.34 at 21 C and atmospheric pressure... 

Carbonyl dibromide is a dense, colourless, mobile liquid, fuming in moist air due to hydrolysis, with an odour similar to that of phosgene [2126]. Its relative molecular mass is 187.8184. It is much less stable to dissociation than phosgene even distillation at atmospheric pressure results In a slight yellow colouration due to liberated bromine. 

Under normal conditions of temperature and pressure, COCIF is a gas. It is colourless in both the gaseous and condensed states, and has an odour similar to, but distinguishable from, phosgene. It is non-flammable. 

COBrF is described [1751] as having an odour similar to that of phosgene, and... 

Only a few of the physical properties of COBrF have been measured. Carbonyl bromide fluoride (relative molecular mass 126.91) is a colourless gas, with an odour similar to, but distinguishable from, phosgene [1195]. The melting point at atmospheric pressure of COBrF has been reported as -120 2 C [1196a], and the boiling point as -20.6 "C [1196a]. Its critical temperature occurs at +124 C, and its critical pressure is ca. 6.18 MPa [656a,1751]. 

There are no reports concerning the preparation of carbonyl chloride iodide, COCII. When exposed to moist air, however, chlorodiiodomethane, CHCIIj, is reported to develop a phosgene-like odour [90b]. If phosgene is formed during this process, it is probable that it arises as a result of the following reactions ... 

Triphosgene. White crystals, mp 79°C. Odour of phosgene. Effects similar to phosgene qv. 

Carbonyl chloride, CG, Collongite, D-stoff. Used by Germany as a mixture with chlorine at Nieltje in Flanders on December 19th 1915. 88 tons released 1069 casualties, 129 fatal. 80% of WWI gas fatalities due to phosgene. Colourless gas, bp 8°C with odour variably described as new-mown hay or mouldy hay. Tobacco... 

Colourless liquid, bp 69.2°C. Smoke-producing agent, pungent odour, corrosive to skin and mucous membranes. Used by the British and French in WWI as a mixture with phosgene and chloropicrin. 

Diphosgene, Surpalite, Perstoff. Colourless liquid, odour of phosgene, bp 128°C. Less irritant than the mono- and di-forms but has the lungdamaging properties of phosgene. Used in shells in WWI. 

Disulphur decafluoride. Made in the UK in 1934. High toxicity, no odour. In rhesus monkey, was one tenth as toxic as phosgene. 

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