Question 160Refrigeration & AC - 1st Asst/Chief

The correct answer is D) phosgene gas. When chlorinated fluorocarbon refrigerants, such as those used in refrigeration and air conditioning systems, are exposed to open flames or hot surfaces, they can decompose and form the highly toxic gas phosgene. Phosgene was previously used as a chemical weapon due to its severe toxicity. The formation of phosgene is a dangerous byproduct that can occur when these types of refrigerants are not properly handled near ignition sources. The other answer choices are incorrect because: A) petroleum crystals are not a byproduct of this reaction, B) water vapor is not produced, and C) carbon monoxide is not the primary hazardous substance formed.