Why should gloves, eye protection, and protective clothing be worn during filling procedures?

Wearing gloves, eye protection, and protective clothing during filling procedures is crucial primarily to prevent freeze burn and frostbite. When handling liquefied petroleum gas (LPG) or other cryogenic fluids, these substances can exist at very low temperatures. If these fluids come into contact with skin or mucous membranes, they can cause severe frostbite or freeze burns. Protective gear shields the body from these extreme temperatures, ensuring safety during the process.

While other options mention potential hazards and legal requirements, the direct physical risk posed to workers during filling operations primarily revolves around the temperatures involved in handling gas. Thus, the correct answer highlights the importance of safeguarding against these specific thermal injuries.