It’s really not a simple answer and requires an understanding of general biosafety. The World Health Organization (WHO) defines biosafety as principles, practices, and strategies aimed at minimizing the unintentional release of a biological agent. Biosafety is achieved by utilizing the four primary controls – engineering, PPE, standard operating procedures (SOPs), and administration. These controls work together to protect people, animals, and plants inside and outside the laboratory environment. Laboratories are seen as containment facilities, places where biological agents are worked with and the risks associated with that work are “contained.”
Millions of dollars are spent on engineering controls – the purchasing of biosafety cabinets, autoclaves, self-closing doors, hands free sinks, directional airflow, and HEPA filters. Thousands of dollars are spent on PPE, which includes gloves, booties, lab coats, and respirators. Hundreds of hours are spent writing SOPs which aim to produce consistent behavioral practices among different individuals, with different educational backgrounds and levels of expertise surrounding biological risks within specific environments. However, one individual can negate all these controls in an instant with poor practices. The focus of the fourth primary control (administration) is people and includes training, SOP compliance programs, medical and incident surveillance, and performance verification of laboratory staff skills and abilities.
No control is more important than the other. Each control offers a level of redundancy, allowing for failures to occur while still offering protection to those working in the laboratory environment. For example, a spill which occurs outside the biosafety cabinet is an engineering failure. However, wearing eye protection, gloves, responding appropriately according to the SOP, having the proper training for cleaning the spill, and learning from the incident ensures the safety of the laboratory worker. Together the four primary controls protect you.
So, the original question was – what is the purpose of PPE? There are two purposes for PPE. First, you wear PPE to protect all portals of entry from biological risks. Typically, laboratory staff is working with something which could make you or others sick. PPE serves as the barrier between your body (a viable host) and the biological agent. This is why you may be asked to wear gloves, eye protection, lab coats, and respirators. Each one of these protects portals of entry from biological risks.
The second reason we wear PPE is because we want to keep what we are working with in the laboratory. If you leave the laboratory, remove your PPE – especially your gloves. If you have to carry something from one place to another, put what you are carrying in a secondary container (cooler or Ziploc® bag). PPE removal prior to exiting the laboratory is a CDC and NIH requirement for BSL2 laboratories. “Personnel must remove gloves prior to exiting the laboratory environment” (page 37-4b, 5th Edition of the CDC/NIH BMBL). In addition, potentially infectious materials must be placed in a durable, leak-proof container during transport within a facility (page 35 – 6th Edition of the CDC/NIH BMBL).
The biologist, Thomas Huxley, once said, “It is not who is right, but what is right, that is of importance.” Laboratory staff have a responsibility to keep what they work with in the laboratory. PPE is not just protection for laboratory staff (by protecting all portals of entry). PPE is protection for everyone outside the laboratory, too. PPE protects non-laboratory personnel ONLY WHEN all PPE is removed before exiting the facility.
Modified from “What is the Purpose of Personal Protective Equipment (PPE)” by Sean Kaufman.