At high temperatures, such as open flames and glowing metal surfaces, what can R-12 and R-22 decompose to form?

• A. Hydrochloric Acid
• B. Phosgene Gas
• C. Carbon Dioxide
• D. Chlorine Gas

Answer: (B)

At high temperatures, such as those encountered in the presence of open flames and glowing metal surfaces, R-12 (dichlorodifluoromethane) and R-22 (chlorodifluoromethane) can undergo thermal decomposition. This process is particularly concerning because it can produce phosgene gas, which is highly toxic and poses serious health risks.

Phosgene is a chemical compound that, despite its use in industry, can lead to severe respiratory and other health issues upon exposure. The breakdown of refrigerants in the presence of extreme heat can involve various reactions, but the formation of phosgene is one of the most significant hazards associated with the combustion of these chlorinated hydrocarbons.

While hydrochloric acid, carbon dioxide, and chlorine gas can also be products of the decomposition of chlorinated compounds, the specific concern at high temperatures with R-12 and R-22 primarily includes phosgene due to its lethality and the specific chemical reactions that occur in that environment. Understanding this aspect of refrigerant safety is crucial, particularly for those working in refrigeration and HVAC industries, to mitigate risks associated with heating and fire hazards.