LAB SAFETY

Destruction of all forms of life including bacterial spores

Sterilization

Pressure saturated steam at 121°C for 15-20 minutes

Autoclave

A chemical or physical agent that is applied to inanimate objects to kill microbes

Disinfectant

A chemical agent that is applied to living tissue to kill microbes

Antiseptic

Reducing the number of viable microorganisms present in a sample

Disinfection

A type of disinfectant that is a cationic detergent, reduces surface tension of molecules in a liquid, and is ineffective against Pseudomonas aeruginosa

Quaternary ammonium compounds (Quats)

An antimicrobial agent that kills a microorganism

Bactericidal

A condition where the multiplication of bacteria is inhibited without killing them

Bacteriostatic

Use of chemicals to kill or inhibit the growth of microorganisms

Chemical disinfection

Use of methods such as heat, UV light, and filtration to kill or inhibit organisms

Physical disinfection

Sterilization method using ethylene oxide gas, used for objects that cannot be autoclaved like plastic products, with a relative humidity of 30% needed to destroy spores

Gas sterilization

Microorganisms in blood or other body fluids that can cause illness and disease in people

Blood-borne pathogens

A form containing data about the properties, safe use, and potential hazards of a particular substance

Material Safety Data Sheets (MSDS)

Includes all types of equipment used to increase individual safety while performing potentially hazardous tasks

Personal Protective Equipment (PPE)

The principle of treating all blood and body fluids as potentially infectious and capable of transmitting HIV or other diseases

Standard Precautions

A US federal agency charged with the enforcement of safety and health legislation

Occupational Safety and Health Administration (OSHA)

Hoods that act as containment barriers protecting laboratory scientists from aerosol transmission of microorganisms

Biological Safety Cabinets (BSC)

Bacteria highly resistant to disinfectants due to their thick protein coat and the presence of calcium dipicolinate in their endospores

Spore-forming bacteria

The total number of microorganisms present in a sample, requiring longer exposure to disinfectants when higher

Microbial load / Bioburden

A measure of how much disinfectant is used, where higher concentrations improve effectiveness but can also be dangerous

Concentration of Disinfecting Agent

Substances like blood, mucus, and pus that inactivate disinfecting agents and should be removed before disinfection

Presence of Organic Material

The specific characteristics of a material that determine the appropriate disinfection method

Nature of Surface to be Disinfected

The duration required for a disinfectant to remain in contact with a microorganism for destruction

Contact Time

A factor that is directly proportional to the degree of disinfection

Temperature

A community of bacteria that forms a protective material over them, shielding them from environmental factors, often found in catheters and water pipes

Biofilms

The need to consider the interactions of multiple disinfectants, as some may neutralize each other (e.g., bleach and quats)

Compatibility of Disinfectants

The most reliable method of sterilization for articles that can withstand heat

Heat

Sterilization method that involves exposure to high temperatures in an electrically heated oven

Hot air oven

The process of removing bacteria by trapping them in a filter rather than killing them

Filtration

A type of radiation known as “cold sterilization” because it does not generate heat

Radiation

A method of disinfection where bacteria are exposed to sound waves of frequencies greater than 20,000 cycles per second

Sonic and Ultrasonic Vibrations

A type of radiation with low energy and poor penetrative power that inhibits DNA replication, but does not kill spores

Non-ionizing Radiation

A type of radiation with high energy and good penetrative power that damages the nucleic acids of microorganisms and is sporicidal

Ionizing Radiation

Filters that are at least 99.97% efficient in removing airborne particles greater than 0.3 µm in diameter

HEPA Filters

A biosafety risk group that includes agents not known to cause disease in humans

Risk Group 1 (RG1)

A biosafety risk group that includes agents that cause human disease but are unlikely to be a serious hazard due to available treatments

Risk Group 2 (RG2)

A biosafety risk group that includes pathogens that cause serious human disease but may have available treatments

Risk Group 3 (RG3)

A biosafety risk group that includes highly infectious agents that cause life-threatening diseases and have no available treatment

Risk Group 4 (RG4)

A containment barrier that protects laboratory workers by sterilizing both recirculated and exhausted air

BSC Class II

A fully enclosed biosafety cabinet with negative pressure that completely protects workers from biohazard exposure

BSC Class III

The recommended autoclave temperature and time for sterilizing medical waste

132°C for medical waste

The temperature and time required for dry heat sterilization at 160°C

60 minutes at 160°C

The temperature and time required for dry heat sterilization at 170°C

40 minutes at 170°C

The temperature and time required for dry heat sterilization at 180°C

20 minutes at 180°C

The boiling temperature of water that kills most vegetative bacteria and viruses immediately

100°C

The contact time for iodine and alcohol to effectively disinfect surfaces

1-2 minutes

A temperature-sensitive sterilization method that utilizes free steam at 100°C for 90 minutes

Steam at 100°C

The standard pressure used in autoclaves to achieve sterilization at 121°C

1/15 psi

A surface disinfectant commonly used in healthcare that requires a 1:10 dilution for blood spills

Sodium hypochlorite (bleach)