Environmental, Health and Safety Services

Biosafety Definitions


see Animal Biosafety Level


see Arthropod Containment Level

Animal Biosafety Level (1-3)

The vertebrate animal vivarium biosafety criteria which includes combinations of practices, safety equipment, and facility design requirements for experiments with animals involved in infectious disease research. These ascending levels, provide increasing protection to personnel and the environment, and are recommended as minimal standards for activities involving infected lab animals.


The application of a chemical to living tissue for the purpose of preventing infection.

Arthropod Containment Level (1-3)

These ascending levels of arthropod containment add increasingly stringent measures and are similar to biosafety levels. Each level includes a combination of practices, safety equipment, and facility design requirements. The arthropod containment levels address arthropods of public health importance, such as those that transmit pathogens. Arthropods that cause myiasis, infestation, biting, and stinging are not included. Most uses of Drosophila spp. are also specifically excluded.


An agent of biological origin that has the capacity to produce deleterious effects on humans, i.e., microorganisms, toxins and allergens derived from those organisms; and allergens and toxins derived from higher plants and animals.

Biohazardous waste

Solid or liquid waste potentially contaminated with biological agents which is capable of causing disease in human, plants and animals or contains materials harmful to the environment. Examples include general zoonotic vectors used in research and cultures used in human, animal, or plant pathology research. Other materials may include recombinant DNA-containing plants, plant-associated microorganisms, and plant-associated small animals such as arthropods. All decontaminated biohazardous, non-infectious solid waste may be disposed of with household trash provided no “biohazard” wording or symbols are visible on outer containers.

Biological agent

An organic entity, typically microscopic, which may be pathogenic to humans, animals or plants. Examples: bacteria, viruses, prions, protozoa, fungi.

Biological Indicator (BI)

A commercially produced, standardized test system containing viable microorganisms (e.g., Geobacillus stearothermophilus) which provides a defined resistance to a specified sterilization process.

Biological safety cabinet

A ventilated cabinet which uses a variety of combinations of HEPA filtration, laminar air flow, and containment to provide personnel, product, or environmental protection against particulates or aerosols from biohazardous agents. It is distinguished from a chemical fume hood by the presence of HEPA filtration and the laminar nature of the air flow. Biological safety cabinets must NOT be used for procedures with hazardous chemicals.


The application of knowledge, techniques and equipment to prevent personal, laboratory, and environmental exposure to potentially infectious agents or biohazards. Biosafety defines the containment conditions under which infectious agents can be safely manipulated. The objective of containment is to confine biohazards and to reduce the potential exposure of the laboratory worker, persons outside of the laboratory, and the environment to potentially infectious agents.

Biosafety Level (1-3)

The laboratory biosafety level criteria, designated in ascending order by degree of protection provided to personnel, the environment, and the community. The levels establish combinations of practices, safety equipment, and facility design requirements to address the increasing risk of handling agents requiring increasing levels of containment.

Biosafety Level (1-3) Plants

These levels specify the physical and biological containment conditions and practices suitable to the greenhouse conduct of experiments involving recombinant DNA-containing plants, plant-associated microorganisms (i.e., viroids, virusoids, viruses, bacteria, fungi, protozoans, certain small algae, and microorganisms that have a benign or beneficial association with plants, such as certain Rhizobium species and microorganisms known to cause plant diseases), and plant-associated small animals (e.g., arthropods).

Bloodborne pathogen

Any pathogenic microorganism that is present in human blood and can cause disease in humans. These pathogens include, but are not limited to, hepatitis B virus (HBV) and human immunodeficiency virus (HIV).


see Biological Safety Cabinet


see Biosafety Level


see Biosafety Level Plants

Chemical Indicators (CIs)

Devices used to monitor the attainment of one or more of the parameters required for a satisfactory sterilization process, or are used in specific tests of sterilization equipment.

  • External CI
    • Class 1 (process indicator): CI intended for use with individual units (e.g., packs, containers, bags) to demonstrate that the unit has been exposed to the sterilization process and to distinguish between processed and unprocessed units. This type is commonly referred to as “autoclave or sterilizer indicator tape.”

  • Indicators for use in specific tests
    • Class 2 (Bowie-Dick test indicator): CI designed to use in a specific test procedure (e.g., the Bowie-Dick test used to determine if air removal has been adequate in a steam sterilization process). Use of Bowie-Dick indicators is not required for this program.
  • Internal CIs
    • Class 3 (single-parameter indicator): CI designed to react to one of the critical parameters of sterilization and to indicate exposure to a sterilization cycle at a stated value of the chosen parameter.
    • Class 4 (multi-parameter indicator): CI designed to react to two or more of the critical parameters of sterilization and to indicate exposure to a sterilization cycle at stated values of the chosen parameters.
    • Class 5 (integrating indicator): CI designed to react to all critical parameters over a specified range of sterilization cycles and whose performance has been correlated to the performance of a BI under the labeled conditions of use.


Use of physical or chemical means to render an area, device, item, or material safe to handle (i.e., safe in the context of being reasonably free from a risk of disease transmission). The primary objective is to reduce the microbial load so that infection transmission is eliminated. Steam sterilization (via autoclave use) is the preferred method when processing biohazardous waste.


The chemical or physical treatment that destroys most vegetative microbes (or viruses), but not spores, in or on inanimate objects/substances.

Etiologic agent

An agent responsible for the occurence of a microbial disease.

Infectious substance

A substance containing a viable microorganism, such as a bacterium, virus, rickettsia, parasite, or fungus, that is known or reasonably believed to cause disease in humans or animals.

Infectious waste

Any solid or liquid waste that is capable of producing an infectious disease in humans. This includes waste potentially contaminated with agents likely to be pathogenic to healthy humans, such as those not routinely or freely available in the community, and which may be present in sufficient quantities and with sufficient virulence to transmit disease. Decontaminated solid, infectious waste must be disposed of as Regulated Medical Waste through EHS.

Specific categories of infectious waste:

  • Cultures and stocks of microorganisms and biologicals
    • Discarded cultures, stocks, specimens, vaccines and associated items likely to have been contaminated by them
    • All cell culture materials
    • Discarded etiologic agents
    • Wastes from the production of biologicals or antibiotics possibly contaminated by organisms capable of producing human infectious disease
  • Human blood and human body fluids
    • Includes items contaminated with human blood or human body fluids.
  • Tissues and other anatomical wastes
    • Human tissues, organs, or body parts
  • Sharps
    • Items capable of puncture and likely to be contaminated with organisms that are pathogenic to healthy humans
    • Needles, syringes with attached needles, suture needles, scalpels, razors, blades
    • Pipettes, pipette tips
    • Slides, cover glasses
    • All sharps generated through veterinary practice
  • Animal carcasses, body parts, bedding and related wastes
    • Includes animals which are intentionally infected with organisms likely to be pathogenic to healthy humans for the purposes of research, in vivo testing, production of biological materials or any other reason.
  • Any residue from cleanup of an infectious waste spill (soil, water, other debris)
  • Any solid waste contaminated by or mixed with infectious waste
    • Specimen containers
    • Disposable gloves, lab coats, masks, etc.


Means work with substances in which the containers used for the handling of substances are designed to be easily and safely manipulated by one person.

Regulated medical waste

means any waste capable of producing an infectious disease in humans.


The reduction of microbial load on an inanimate surface to a “safe” public health level.

Select agent or toxin

A microorganism (virus, bacterium, fungus, rickettsia) or toxin listed by the CDC. This term also includes:

  • Genetically modified microorganisms or genetic elements from organisms listed as select agents, shown to produce or encode for a factor associated with a disease, and
  • Genetically modified microorganisms or genetic elements that contain nucleic acid sequences coding for any of the toxins listed as a select agent, or their toxic submits.

Steam sterilization

A validated process, after which the probability of a microorganism surviving on an item subjected to treatment is less than one in one million (10-6). This is referred to as the “sterility assurance level.”


Free from living organisms, especially microorganisms.


Any infectious disease that is able to be transmitted (vectored) from other animals, both wild and domestic, to humans or from humans to animals (the latter is sometimes called reverse zoonosis).