Chapter 3 - Principles of Biosafety
3.1 Introduction
A fundamental objective of any biosafety program is the containment of potentially harmful
biological agents. The term “containment” is used in describing safe methods, facilities and
equipment for managing infectious materials in the laboratory environment where they are being
handled or maintained. The purpose of containment is to reduce or eliminate exposure of
laboratory workers, other persons, and the outside environment to potentially hazardous agents.
The most important element of containment is strict adherence to standard microbiological
practices and techniques. Knowledge of standard microbiological practices and techniques is gained
through a combination of training and experience.
3.2 Engineering Controls
Engineering controls eliminate or reduce the exposure of individuals to hazards in the laboratory
through the use of specialized equipment. In most cases, engineering controls will be the primary barrier
between hazardous materials and the individual. Engineering controls include:
Biological safety cabinets (BSCs) (discussed in Appendix A)
Other enclosures
Safety centrifuge cups
Retractable needles
3.3 Personal Protective Equipment
Personal protective equipment (PPE) is equipment that the individual wears to protect them from
exposure to hazards in the laboratory. PPE is generally intended to be a secondary barrier meaning that
it is to be used in conjunction with engineering controls to protect the user. PPE may be used a primarybarrier when engineering controls are not possible or feasible.PPE worn should be based on the hazard
present and can include:
Gloves
Safety glasses or splash goggles
Lab coat
Gown
Shoe covers
Boots
Respirator (includes dust masks)
Face shield
3.4 Facility Construction and Design
The design and construction of the facility provides a secondary barrier to protect persons outside the
laboratory. PI’s are responsible for providing facilities commensurate with the laboratory’s function and
the recommended biosafety level for the agents being manipulated. The recommended secondary
barrier(s) will depend upon the risk of transmission of specific agents. For example, the exposure risks
for most laboratory work in BSL-1 and BSL-2 facilities will be direct contact with the agents, or
inadvertent contact exposures through contaminated work environments. Secondary barriers in these
laboratories may include separation of the laboratory work area from public access, availability of a
decontamination facility (e.g., autoclave) and hand washing facilities.