![]() Below 50 ppm/ min, clinical pulmonary symptoms are not expected. At 1 - 3 ppm/ min, irritant effects may be expected. Concentrations exceeding 2 ppm/ min or more have been classified as immediately dangerous to life or health (IDLH) by the Centers for Disease Control and Prevention. ![]() The detection threshold in humans has been reported to be 0.125 ppm/ min. However, low doses of inhaled phosgene may present with few or no upper respiratory symptoms but may accumulate enough in the lower respiratory unit to cause delayed respiratory failure. Symptom onset is inversely proportional to the concentration exposed high concentrations of phosgene inhaled confer a more rapid onset of symptoms and a poorer prognosis. Once inhaled, the concentration and duration of exposure predict the sequelae of events and the progression of the disease. The severity of the disease has been previously proposed to follow Haber's law indicating predicted Toxicity by Inhalation Toxicity = Concentration x Time. Phosgene exists in the gaseous phase at room temperature. In severe cases, the fulminant interstitial edema may progress to acute respiratory distress syndrome (ARDS). As the blood-air barrier receives further insult, diffuse alveolar hemorrhage may occur. The combination of surfactant loss and a compromised air-blood barrier leads to pathognomonic noncardiogenic pulmonary edema, which impairs gas exchange by increasing the diffusion distance for oxygen. Īs phosgene's toxicity ensues, its degradation into HCl is also thought to worsen tissue insult. The degradation of surfactant components leads to impaired respiratory mechanics and loss of the air-blood barrier, causing widespread atelectasis. Modern theories of phosgene toxicity propose that the carbonyl group reacts with primary amine, hydroxide, and mercapto groups leading to cellular breakdown and reactive oxygen species, which deplete pulmonary glutathione stores. Phosgene reacts with surfactant and other functional groups found in the lower respiratory epithelium. Phosgene's lone carbonyl group makes it a highly reactive molecule. The combination of its unassuming odor and poor detection by humans makes phosgene particularly dangerous. However, only 10% of the population may appreciate this odor at concentrations reaching 2 ppm. Reports have described it as musty or similar to freshly mowed grass or hay. Ĭharacteristically, phosgene has a distinct odor. Phosgene is denser than air, and thus during exposure, it can be expected to accumulate in low-lying, poorly ventilated, or enclosed regions. Recently, the Environmental Protection Agency (EPA) identified 123 sites in the United States that could expose millions of people to phosgene if the plant were to malfunction or become a target of bioterrorism. Stratified by country, China produces 37% of the world's phosgene, followed by Europe (31%) and North America (20%). ![]() Global estimates indicate more than 12 million metric tons of this chemical are produced annually. Phosgene exists in the gaseous phase at room temperature but may be stored in the liquid phase below 8.2 degrees Celsius. Using barbeques or camping stoves inside, and turning on vehicle or lawn mower engines in your garage, can also cause a build-up of carbon monoxide.Current research is directed toward phosgene's potential as a bioterrorism weapon and in industrial settings where phosgene production is unregulated. Causes of carbon monoxide poisoningĬommon household appliances used for heating and cooking can produce carbon monoxide if they are not installed properly, are faulty, or are poorly maintained.Īppliances that can cause carbon monoxide include: They may get worse when you spend time in an affected room or building and get better when you leave or go outside. ![]() Symptoms of carbon monoxide poisoning include: Check if you have carbon monoxide poisoningĬarbon monoxide gas is colourless and does not smell, so you cannot tell if it is around you. Carbon monoxide can be made by fires and appliances that burn gas, wood, oil or coal. Carbon monoxide is a poisonous gas that can make you seriously ill if you breathe it in. ![]()
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