What hazard could cause a service engineer to experience coughing or irritation to the eyes and throat?

Thermal decomposition refers to the breakdown of refrigerants or other chemicals when exposed to high temperatures or certain conditions, leading to the release of hazardous byproducts. When this occurs, toxic gases such as phosgene or hydrogen fluoride may be produced, which are known to cause respiratory issues and irritation to mucous membranes, including coughing and irritation in the eyes and throat.

Understanding this hazard is particularly important for service engineers who work with refrigerants, as they may encounter situations where overheating or improper handling of these materials can lead to thermal decomposition. This underlines the importance of using appropriate safety measures, such as proper ventilation, personal protective equipment, and adherence to guidelines for handling and storing refrigerants safely.

The other options may pose risks in different contexts but do not specifically relate to the immediate effects of coughing or throat and eye irritation tied to the conditions created during thermal decomposition. High-pressure refrigerants involve safety risks related to physical injuries rather than respiratory irritation, ozone depletion is a long-term environmental issue, and excessive humidity affects comfort levels but is not typically associated with acute respiratory symptoms in the same manner.