Phosgene was still stockpiled in military arsenals well after the Second World War, but its continued presence in the atmosphere today is due to man-made chlorinated hydrocarbons used in the chemical industry.
A team, including Professor Peter Bernath, of the Department of Chemistry at the University of York, has carried out the first study of the global distribution of the gas. The team also involved scientists from the Universities of Waterloo and Toronto in Canada, NASA’s Jet Propulsion Laboratory and the New Mexico Institute of Mining and Technology in the USA.
Between February 2004 and May 2006, they used the Canadian Atmospheric Chemistry Experiment (ACE) satellite to measure the incidence of the gas. The research, which was financed by the Canada Space Agency (CSA) and the Natural Sciences and Engineering Research Council of Canada, is published in the latest edition of Geophysics Research Letters.
The scientists discovered that the main atmospheric concentration of the gas was above the Equator, though it was present in some quantity in all latitudes. They found that levels of phosgene in the atmosphere had reduced since previous studies in the 1980s and 1990s, though its continued presence is a contributor to ozone depletion.
Phosgene plays a major role in the preparation of pharmaceuticals, herbicides, insecticides, synthetic foams, resins and polymers, though its use is being reduced.
Professor Bernath said: ”There is a small, but not negligible, concentration of phosgene in the troposphere. Chlorinated hydrocarbons don't occur in nature but as chlorinated solvents they are used by industry. They are short-lived and they decay rapidly, but they decay into phosgene.
“It's very toxic and pretty nasty stuff - its reputation is well deserved. Considering the health hazards associated with phosgene, the chemical industry is trying to find substitutes to eliminate its use. But the use of chlorinated hydrocarbons is being reduced because of the legal restrictions of the Montreal Protocol, so phosgene is also decreasing.”
Higher up in the atmosphere phosgene can be slowly oxidized by ultraviolet rays, and so it continues to play a role in the depletion of the ozone layer.
David Garner | alfa
Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)
Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers
Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...
Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.
At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...
3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects
A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
21.07.2017 | Event News
19.07.2017 | Event News
12.07.2017 | Event News
25.07.2017 | Physics and Astronomy
25.07.2017 | Earth Sciences
25.07.2017 | Life Sciences