Respiratory protection **should only be relied on as a last measure.**

Respiratory protection **should only be relied on as a last measure** against fumes and gases. According to best practices in occupational health and safety, the preferred hierarchy of controls to prevent exposure to hazardous substances follows this order: 1. **Elimination:** Remove the hazard entirely if possible. 2. **Substitution:** Replace the hazardous substance with a less dangerous one. 3. **Engineering Controls:** Isolate people from the hazard through ventilation systems or barriers. 4. **Administrative Controls:** Change work policies or procedures to reduce exposure. 5. **Personal Protective Equipment (PPE):** Use equipment like respirators to protect individuals when all other methods are not sufficient to control the hazard. Respiratory protection falls under PPE and should be used when other methods are not feasible or are insufficient to adequately manage the risk.