What is considered as the "last line of defense" when reducing the exposure risk to toxicants?

Personal Protective Equipment (PPE) is regarded as the "last line of defense" in mitigating exposure risks to toxicants. This perspective arises from the hierarchy of controls used in workplace safety, which prioritizes methods of risk reduction. In this hierarchy, eliminating the hazard or substituting with less toxic substances ranks highest, followed by engineering controls that prevent exposure through design modifications. Administrative controls, such as standard operating procedures, further enhance safety.

PPE is used when the aforementioned higher-level controls are not feasible or cannot eliminate the risk entirely. It serves as a protective barrier between the worker and the hazardous materials, reducing the likelihood of exposure during tasks where contact with toxicants is still possible. Therefore, while PPE is essential for ensuring worker safety, reliance on it should come after all other methods have been applied, reinforcing its role as the last line of defense.

When considering the other options, they focus on preventative measures—such as equipment design or using less toxic chemicals—which do not act as protective measures themselves but rather aim to eliminate the risk of exposure from the start. These alternatives are critical in the overall safety strategy but do not directly protect individuals after an exposure risk has been introduced.