Recognizing the Biosafety LevelsThis Quick Learn Lesson will take approximately 15 minutes to complete. Show
When you have completed this lesson, you will be able to recognize characteristics of the four biological safety levels. IntroductionSuppose you are a laboratory microbiologist working with a potentially harmful microbe. Precautions must be taken in the laboratory to make sure you and others are not infected.
These are just a few of the questions that can be answered through an understanding of biosafety and the four biosafety levels (BSLs). Biosafety and Biosafety LevelsWhat is Biosafety? What
are Biosafety Levels (BSLs)? Each biosafety level has its own specific containment controls that are required for the following:
BSLs, continuedThe biosafety levels range from BSL-1 to BSL-4. Each biosafety level builds on the controls of the level before it. Every microbiology laboratory, regardless of biosafety level, follows standard microbiological practices. You will learn about each level on the following screens. BSL-1If you work in a lab that is designated a BSL-1, the microbes there are not known to consistently cause disease in healthy adults and present minimal potential hazard to laboratorians and the environment. An example of a microbe that is typically worked with at a BSL-1 is a nonpathogenic strain of E. coli. Specific considerations for a BSL-1 laboratory include the following: Laboratory practices
Safety equipment
Facility construction
BSL-2BSL-2 builds upon BSL-1. If you work in a lab that is designated a BSL-2, the microbes there pose moderate hazards to laboratorians and the environment. The microbes are typically indigenous and associated with diseases of varying severity. An example of a microbe that is typically worked with at a BSL-2 laboratory is Staphylococcus aureus. BSL-2, continuedIn addition to BSL-1 considerations, BSL-2 laboratories have the following containment requirements: Laboratory practices
Safety equipment Facility construction
BSL-3BSL-3 builds upon the containment requirements of BSL-2. If you work in a lab that is designated BSL-3, the microbes there can be either indigenous or exotic, and they can cause serious or potentially lethal disease through respiratory transmission. Respiratory transmission is the inhalation route of exposure. One example of a microbe that is typically worked with in a BSL-3 laboratory is Mycobacterium tuberculosis, the bacteria that causes tuberculosis. BSL-3, continuedIn addition to BSL-2 considerations, BSL-3 laboratories have the following containment requirements: Laboratory practices
Safety equipment Facility construction
BSL-4BSL-4 builds upon the containment requirements of BSL-3 and is the highest level of biological safety. There are a small number of BSL-4 labs in the United States and around the world. The microbes in a BSL-4 lab are dangerous and exotic, posing a high risk of aerosol-transmitted infections. Infections caused by these microbes are frequently fatal and without treatment or vaccines. Two examples of microbes worked with in a BSL-4 laboratory include Ebola and Marburg viruses. BSL-4, ContinuedIn addition to BSL-3 considerations, BSL-4 laboratories have the following containment requirements: Laboratory practices
Safety equipment
Facility construction
Your Turn: ExercisesNow that you have learned about the four biosafety levels, it's your turn to identify the correct BSL in the examples on the following screens. Select the Next icon to begin. Your turn: Exercise 1Select the biosafety level described by the conditions of the following example. Levels are listed below. A microbiology graduate student is working on a project under the following conditions:
Your turn: Exercise 2Select the biosafety level shown in the photo below. Click on the photo for a larger image. Your turn: Exercise 3Select the biosafety level described by the conditions of the following example. Levels are listed below.
Your turn: Exercise 4Select the biosafety level shown in the following photograph below. Click on the photo for a larger image. SummaryCongratulations! You should now be able to recognize characteristics of the four biological safety levels. If you would like additional information or resources on the topic of biosafety, select the Next icon. To view other Quick Learn Lessons, visit CDC Learning Connection. What is the lowest BSL that requires all manipulations of biohazards to take place within biological safety cabinets or other primary containment Encl?BSL-1 is the lowest security level for handling biological material.
What is the lowest BSL that recommends the use of a biological safety cabinet?BSL–1. As the lowest of the four, biosafety level 1 applies to laboratory settings in which personnel work with low-risk microbes that pose little to no threat of infection in healthy adults.
What does BSLBiosafety Level 1 (BSL-1)
BSL-1 labs are used to study infectious agents or toxins not known to consistently cause disease in healthy adults. They follow basic safety procedures, called Standard Microbiological Practices and require no special equipment or design features.
What are BSLBSL-2 laboratories are used to study moderate-risk infectious agents or toxins that pose a moderate danger if accidentally inhaled, swallowed, or exposed to the skin. Design requirements for BSL-2 laboratories include hand washing sinks, eye washing stations, and doors that close and lock automatically.
What are BSLBiosafety level 4 (BSL-4) organisms are dangerous or exotic agents which pose high risk of life-threatening disease, aerosol-transmitted lab infections, or related agents with unknown risk of transmission.
What is biosafety level 3?Biosafety Level 3 (BSL-3) is the recommended containment for work with agents or toxins that may cause serious or potentially fatal disease through inhalation exposure. Work at BSL-3 requires enhanced facility design, operational controls and special practices, which will be outlined in this section.
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