What is the primary reason for using ventilation during welding operations?

Using ventilation during welding operations is crucial primarily because it protects the welder from harmful fumes and gases that are generated during the welding process. Welding produces a range of hazardous substances, including metal fumes, ozone, nitrogen oxides, and various gases that can be toxic if inhaled. These fumes can lead to serious health issues such as respiratory problems, neurological effects, and long-term diseases.

Proper ventilation helps to dilute and remove these hazardous fumes from the workspace, ensuring cleaner air and enhancing the safety and health of the welder. It allows for the continuous supply of fresh air while exhausting contaminated air outside. This practice is vital in maintaining a safe working environment and minimizing exposure to harmful substances.

The other options, while relevant to the welding process, do not address the most critical health and safety concern associated with welding operations. For example, improving visibility for the welder, preventing equipment overheating, and ensuring proper temperature for the weld are all important, but they do not compare to the necessity of safeguarding the welder's health from toxic exposure. Hence, the primary reason for using ventilation is to protect the welder from harmful fumes and gases.