When must you always wear a respirator?

Wearing a respirator is critical to ensure safety while handling hazardous materials, particularly during the mixing and filling of highly toxic pesticides. This activity presents a significant risk for inhalation exposure to potent chemicals that could cause severe respiratory issues or other adverse health effects. The respirator serves as a protective barrier, filtering out harmful particulates and vapors that may be released during the mixing process.

In contrast, other scenarios, while potentially risky, do not universally necessitate the use of a respirator for everyone involved. For example, applying pesticides indoors might require additional safety precautions, but not all products necessitate a respirator in those conditions, depending on their formulation and toxicity levels. Additionally, relying on personal choice or subjective feelings about one's health do not provide enough grounds for determining the necessity of respiratory protection, as the risk factors remain constant regardless of an individual's current condition.