Biosafety is the handling and containment procedures, guidelines, and precautions used to protect the environment, including human and animal health, from the possible adverse effects of infectious microorganisms and other biological hazards.


The purpose of biosafety measures is to protect people, animals, and the environment from exposure to potentially hazardous biological agents or materials. These agents or materials may cause disease or other detrimental effects to humans, animals, and/or plants. Therefore, biosafety is focused on reducing or eliminating the possibility that people who work directly with these materials, the general population, and the environment are exposed.

Hazardous Materials Technician Training Drill at Mercy Medical Center, simulated chlorine release.

Hazardous Materials Technician Training Drill at Mercy Medical Center, simulated chlorine release.


Biosafety encompasses all aspects of safety required when people are working with infectious microorganisms and other biological hazards, also known as biohazards. This includes proper handling and containment procedures, practices, and equipment. The goal of biosafety is to contain biohazards and reduce or eliminate the possibility of exposing people or the environment to these hazards.

There are four biosafety hazard levels used by the Centers for Disease Control and Prevention (CDC) to determine what level of precaution (laboratory practices and techniques, safety equipment, and laboratory facilities) is required for the proper containment of a biohazard. These four levels are also used by the European Union (EU).

Biosafety Level 1 (BSL1) is reserved for microorganisms that are not known to consistently cause healthy adult humans to become sick. BSL1 agents are safe to use in teaching laboratories and for undergraduate and secondary education training. Only a basic level of containment is needed, and other than having a sink for hand washing and personal protective equipment, no other primary or secondary barriers are mandatory. Escherichia coli (E. coli) is an example of a BSL1 hazard.

Biosafety Level 2 (BSL2) materials should only be handled by people who are using personal protection such as splash shields, gloves, and gowns. Secondary barriers are also needed, such as hand washing sinks and waste decontamination facilities. These hazards are not typically transmissible through the air or by being inhaled. Exposure takes place when the agent is ingested or gets into the body through breaks in the skin or by coming in contact with a mucous membrane. Examples of BSL2 agents include HIV and species of Salmonella.

Biosafety Level 3 (BSL3) includes agents that are indigenous or exotic and can be transmitted by being inhaled. These biohazards cause severe to fatal diseases in humans; however, treatments for these diseases exist. Examples include Mycobacterium tuberculosis and St. Louis encephalitis. People who work with BSL3 agents must have proper training in handling biohazards. Primary and secondary barriers are important to protect both those who work with the agents and the outside community. All work with these agents must be performed in a biological safety cabinet (BSC) or other type of enclosed chamber. Access to the laboratory must be secure and ventilation must minimize the risk of the infectious agents being released into the air outside the laboratory.

Biosafety Level 4 (BSL4) includes the most dangerous types of biohazards. These are exotic agents that pose a very high risk of an individual being exposed to a life-threatening disease for which there is no available vaccine or treatment. These agents can be transmitted through the air. Examples include Marburg virus and Congo-Crimean hemorrhagic fever virus. Only specially trained researchers can work with BSL4 agents. These workers must be completely isolated from the agent by using a full-body and airsupplied personal suit. The facility must also be completely isolated, often by being located in a separate building, and must have its own specialized waste management and ventilation systems.


Many people agree that modern biosafety began in the United States on April 18, 1955, when 14 members of the military met together at Camp Detrick (now Fort Detrick) to share knowledge and discuss safety procedures used at three biological warfare laboratories of the U.S. Army. This meeting was subsequently considered to have been the first unofficial meeting on biological safety. The second biological safety conference took place later that same year November 14–17. This meeting was again held in association with the military. Meetings continued once or twice a year, and in 1964, during the ninth and tenth biological safety conferences, the National Institutes of Health and the Communicable Disease Center participated. This was the first time major health and biomedical research agencies of the federal government were included. These two agencies were able to attend because presentations no longer contained restricted classified military information.

Biological safety conferences continued, and by 1966, representatives from hospitals, private laboratories, universities, and industry attended. Discussions about safety and regulations took place. In 1974, regulations were introduced by the U.S. Postal Service and Department of Transportation regarding shipping microorganisms and toxins that cause diseases in humans. Additionally, new safety training and programs were introduced, including the four levels of biosafety, which, as of 2018, were still used by the U.S. Centers for Disease Control and Prevention. In February 2018, the CDC asked Congress for $350 million to build a new laboratory for study of the most deadly pathogens.

An international agreement, the Cartagena Protocol on Biosafety, aimed at ensuring the safe handling, transportation, and use of living modified organisms. It was adopted on January 29, 2000, and went into effect on September 11, 2003. As of 2017, 171 parties had ratified the agreement.


Biosafety comprises three main areas of safety. These are laboratory practice and technique, safety equipment, and facility design.

The most important safety measures in containment are the practices and techniques used by those who work directly with, or in a facility that has, hazardous agents and materials. Anyone who works around biohazards must be aware of the dangers and be trained in proper handling and safety techniques. Laboratories should have clear biosafety rules set in writing. Additionally, laboratories should identify what hazards may be encountered and the specific procedures that are in place to reduce or eliminate the likelihood of exposure. The ASBA manages a voluntary accreditation program for laboratories, with four levels based on a combination of laboratory practices, safety equipment, and facilities. This also includes a category for accreditation as an agricultural animal facility to accredit those with loosely confined animals.

The primary barrier to exposure is proper safety equipment. Biological safety cabinets are the principal devices used in containing hazardous agents and materials. BSCs come in three classes (Class I, II, and III). The class needed depends on the materials being worked with in the facility. Additional safety equipment can include protective clothing (e.g., coats, gloves, boots, face shields, and respirators) and enclosed containers (such as centrifuge cups). Life-threatening pathogens for which there is no treatment, such as smallpox, must be stored in cold rooms or freezers in special select agent containment laboratories. In addition, a vaccine cold chain has been developed to ensure safety in transporting and storing of vaccines, as well as in making it available.

The intentional release of toxic biological agents as weapons or a form of terrorism.
E. coli
Escherichia coli; a bacterium that usually resides harmlessly in the lower intestine but can cause infection elsewhere; also, some infectious strains produce a toxin that causes intestinal illness.
A genus of bacteria that causes food poisoning, acute gastrointestinal inflammation, typhoid fever, and septicemia.
The branch of science that focuses on the effects of outer space on organisms and the search for extraterrestrial life.
An organism that can be seen only through a microscope. Microorganisms include bacteria, protozoa, algae, and fungi.

The design of a facility working with hazardous biological agents and materials is important for keeping both workers and the outside environment safe. Facility design and construction is considered a secondary barrier, meaning it is the second level of precaution used in biosafety programs. The design and safety levels used are determined by the level of threat of the material being handled. Common secondary barriers include a separation between contaminated work environments and public access and a decontamination facility. Doors should be lockable, and the entire facility should have excellent security. In higher-risk facilities, or when the infectious agent can be transmitted through the air, special ventilation and air treatment systems are needed to decontaminate air that may escape to the outside environment.

Although organizations such as the CDC have biosafety regulations, each facility must also determine its own needs for proper containment in order to protect the health of its workers and the outside environment.

Role in human health

See also Centers for Disease Control and Prevention ; Ebola virus disease ; Escherichia coli ; Hemorrhagic fevers ; HIV/AIDS .




Baskin, Carole R., and Alan Zelicoff. Ensuring National Biosecurity: Institutional Biosafety Committees. New York: Academic Press, 2016.

U.S. Department of Health and Human Services. Biosafety in Microbiological and Biomedical Laboratories. 5th ed. Washington, DC: National Institutes of Health, 2016.


Lloyd, John, and James Cheyne. “The Origins of the Vaccine Cold Chain and a Glimpse of the Future.” Vaccine 35, no. 19 (2017): 2115–20.

Weiss, Shay, Shmuel Yitzhaki, and Shmuel C. Shapira. “Lessons to Be Learned from Recent Biosafety Incidents in the United States.” Israel Medical Association Journal 17 (May 2015): 269–73.


Centers for Disease Control and Prevention. “Infographic: 4 Biosafety Lab Levels.” (accessed March 26, 2018).

Connell, Nancy. “Biological Agents in the Laboratory: The Regulatory Issues.” Federation of American Scientists. (accessed March 26, 2018).

Convention on Biological Diversity. “The Cartagena Protocol on Biosafety.” (accessed March 26, 2018).

International Centre for Genetic Engineering and Biotechnology. “General Introduction to Biosafety.” (accessed March 26, 2018).


Association for Biosafety and Biosecurity, 1200 Allanson Rd., Mundelein, IL, 60060, (847) 949-1517, (866) 425-1385, Fax: (847) 566-4580,, .

Convention on Biological Diversity, 413 Saint-Jacques St., Ste. 800, MontrealQuebec, Canada, H2Y 1N9, (514) 288-2220, Fax: (514) 288-6588,, .

International Centre for Genetic Engineering and Biotechnology Biosafety, Padriciano 99, Trieste, Italy, 34149, 39(040) 3757320, Fax: 39(040) 226555,, .

United Nations Environment Programme Global Environment Facility, UNEP-GEF Biosafety Unit DEPI, UNEP. PO Box 30553, 00100, Nairobi, Kenya, 254(20) 7624066,, .

United States Centers for Disease Control and Prevention (CDC), 1600 Clifton Rd., Atlanta, GA, 30333, (404) 639-3534, (800) CDC-INFO (800-232-4636); TTY: (888) 232-6348,, .

Tish Davidson, AM
Revised by Teresa Odle, BA, ELS

  This information is not a tool for self-diagnosis or a substitute for professional care.