Phosgene gas

Health and Safety. Remover formulas that are nonflammable may be used in any area that provides adequate ventilation. Most manufacturers recommend a use environment of 50—100 parts per million (ppm) time weighted average (TWA). The environment can be monitored with passive detection badges or by active air sampling and charcoal absorption tube analysis. The vapor of methylene chloride produces hydrogen chloride and phosgene gas when burned. Methylene chloride-type removers should not be used in the presence of an open flame or other heat sources such as kerosene heaters (8). 

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... 

Fire Hazards - Flash Point (deg. F) 162 OC Flammable Limits in Air (%) 1.2 - 4.9 Fire Extinguishing Agents Foam, carbon dioxide, dry chemical, water fog Fire Extinguishing Agents Not To Be Used Water spray. Do not allow water to enter containers Special Hazards of Combustion Products Highly poisonous phosgene gas forms during fires Behavior in Fire At fire temperature the... 

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

Trichloromethyl chloroformate (diphosgene) is used as a safe substitute for highly toxic phosgene gas. The latter is generated in situ by addition of catalytic amounts of tertiary amines or amides, or active carbon. Diphosgene also disproportionates to 2 equivalents of phosgene on heating above 250°C. 

The upper and lower respiratory tracts respond differently to the presence of toxicants. The upper respiratory tract is affected mostly by toxicants that are water soluble. These materials either react or dissolve in the mucus to form acids and bases. Toxicants in the lower respiratory tract affect the alveoli by physically blocking the transfer of gases (as with insoluble dusts) or reacting with the wall of the alveoli to produce corrosive or toxic substances. Phosgene gas, for example, reacts with the water on the alveoli wall to produce HC1 and carbon monoxide. 

Personal Protective Equipment Phosgene is a severe respiratory tract and skin irritant, and contact with the liquid will cause frostbite. Respiratory protection requires positive-pressure-demand, self-contained breathing apparatus (SCBA), while skin protection requires chemical-protective clothing since phosgene gas can cause skin irritation and burns. NIOSH recommends protective suits from Responder (Kappler Co.), Tychem 10000 TM (DuPont Co.) or Teflon (DuPont Co.). 

A victim of phosgene gas during the war, Dupont had been returned from the front and assigned to work in the factories of Trefileries du Havre, where he created a laboratory of research and analysis for the production of steel and metal alloys. He was unusual among French academic scientists in his interest in industrial processes, and later, as an administrator in the CNRS, he pressed for better links between the universities and industry in France.46... 

The following equation represents the equilibrium reaction for the dissociation of phosgene gas. 

When chloroform is heated to decomposition, phosgene gas is formed (NIOSH, 1997). At temperatures greater than 450 °C, tetrachloroethane, HCl, and various chlorinated hydrocarbons are formed. Heating chloroform in the presence of dilute caustics (e.g., sodium hydroxide) yields formic acid (WHO, 1994). 

In comparatively rare cases, two molecules combine to form only one new molecule thus a molecule of carbonic oxide and one of chlorine combine to form one molecule of carbonic oxydiohloride or phosgene gas but the union is oven here essentially atomic for after combination both the oxygon and chlorine are directly united with the atom of carbon ... 

Perchloromethyl — Fire Hazards Flash Point (deg. F) Not flammable Flammable Limits in Air (%) Not flammable Fire Extinguishing Agents Not pertinent Fire Extinguishing Agents Not to be Used Not pertinent Special Hazards of Combustion Products Very irritating vapors formed from hot material. May form toxic phosgene gas, hydrogen chloride and sulfur dioxide Behavior in Fire ... 

Organic Synthesis Industry Additives in deodorizing powder, absorption of phosgene gas, preservation of fresh products... 

Uses In compositions for protection against phosgene gas. In incendiary compositions.22 See Phenate Hexamine. 

Uses Was used in World War I in the so-called P, H. helmets as a protection against phosgene gas. 

Carcinogen if old, forms deadly phosgene gas inhalation and contact hazard... 

Phosgene is nonpersistent in the envhonment. Moisture reduces air concentrations (Borak and Diller, 2001). The potential for secondary contamination of rescue personnel is low, but rescuers should wear proper protective clothing. Phosgene gas does not persist in fabric or leather. 

This process is only applicable to the waste streams containing proper organic waste. Moreover, chlorinolysis produces hydrochloric acid and phosgene gas as an effluent, which are further treated. The leakage of chlorine is another hazard associated with this process. 

---