Personal Protective Equipment and Personnel Safety
PPE is the last line of defense - it protects the individual but does not reduce the hazard at the source. Candidates must know the standard PPE set for BSL-2 (gloves, lab coat or gown, eye/face protection as needed) and BSL-3 (solid-front gowns, dedicated footwear, respiratory protection when indicated, and full coverage). Understand the role of respiratory protection and the difference between a fit test (validates the seal) and a user seal check (performed each donning). N95 respirators filter particulates; powered air-purifying respirators (PAPRs) reduce breathing resistance and are common in high-containment work.
Know the donning and doffing sequence and the principle that contaminated PPE is removed last-to-first in reverse order of contamination, with hand hygiene at critical points. Gloves are the most frequently compromised item - double-gloving is common at BSL-3/4, and gloves must be changed when torn or visibly contaminated.
Traps: treating PPE as a substitute for engineering controls; assuming a surgical mask provides respiratory protection equivalent to an N95; forgetting that jewelry and loose hair interfere with PPE fit; assuming one glove type fits all chemicals and biologics.
Rule of thumb: PPE selection follows the exposure route - splash → eye/face and gown; aerosol → respiratory protection plus containment; contact → gloves and gown.
Worked example: A worker in a BSL-3 lab performing an aerosol-generating procedure should be in a BSC, wearing a solid-front gown, double gloves, and a fit-tested respirator, with doffing performed in a defined sequence and hand hygiene between steps.