P2. MLS 037 SAS 6

in 1974

CDC published the Classification of Etiological Agents on the Basis of Hazard

National Institute of Health (NIH)

published the guidelines for Research Involving Recombinant DNA Molecules

CDH and NIH

jointly published the Biosafety in Microbiological and Biomedical Laboratories (1984)

Biosafety

containment principles, technologies and practices that are implemented to prevent unintentional exposure to pathogens and toxins

Biosecurity

refers to the protection, control and accountability for valuable biological materials within laboratories, in order to prevent their unauthorized access, loss, theft, misuse, diversion or unintentional release

Charles Baldwin

created the biohazard symbol

Risk Group 1

Includes microorganisms that are unlikely to cause

human or animal disease.

- Low individual & community risk

Risk Group 2

- Includes microorganisms that are unlikely to be a

significant risk to laboratory workers and the

community, livestock or the environment

- Laboratory exposure may cause infection but effective

treatment & preventive measures are available

- Moderate individual & limited community risk

Risk Group 3

- Includes microorganisms that are known to cause

serious diseases to humans or animals.

- May present a significant risk to laboratory workers

- High individual & limited to moderate community risk

Risk Group 4

- Includes microorganisms that are known to produce life-

threatening diseases to humans or animals.

- Present a significant risk to laboratory workers

- Readily transmissible; effective treatment & preventive

measures are usually not available

- High individual & community risk

Biosafety Level 1 (BSL- 1)

- Suitable for work involving agents that have no known potential for

infecting healthy people.

- This containment level is used in laboratory activities of students (for

academic purposes).

- Some examples of pathogens that requires this containment level are

Bacillus subtilis and Naegleria gruberi

Biosafety Level 2 (BSL- 2)

- Basically designed for laboratories that deal with agents acquired by

ingestion or exposure to percutaneous or mucous membrane

- Includes all the common agents of infectious diseases

- In handling these agents, access to the laboratory is limited.

- It also requires the personnel to change their clothes with the

recommended laboratory clothing before going to their specific stations.

- The personnel should also receive immunizations.

- Some examples of pathogens that require this containment level are HIV,

- Bacillus anthracis, Yersinia pestis, Salmonella, and Shigella.

Biosafety Level 3 (BSL- 3)

- Puts emphasis on primary and secondary barriers in the protection of the

personnel, community and environment from infectious aerosol exposure.

- In processing these lethal pathogens, the air movement in the laboratory

must be controlled to contain the infectious materials.

- Some examples of pathogens that require this containment level are

Mycobacterium tuberculosis, Francisella tularensis, Brucella spp., Coxiella

burnetii, St. Louis encephalitis virus, and systemic fungi.

Biosafety Level 4 (BSL- 4)

- Is required for work with dangerous and exotic agents that pose high individual risk of

life- threatening diseases that may be transmitted via the aerosol route, for which

there are no available vaccines or treatment.

- Specific practices, safety equipment and appropriate facility design & construction are

required

- Employs a Class III biosafety cabinet or in a full- body, air- supplied positive- pressure

personnel suit.

- Some examples of BSL-4 pathogens include filoviruses (e.g., Ebola, Marburg), select

arenaviruses (e.g., Lassa, Junin), and smallpox virus (Variola virus). Only a few

arboviruses, such as Crimean-Congo hemorrhagic fever virus, require BSL-4 containment.

BIOLOGICAL SAFETY CABINET

- A device that encloses a working area to

protect workers from aerosol exposure

and infectious disease agents.

- In BSC, the air containing the infectious

material is sterilized, either by heat, UV

light, or by passage through a high

efficacy particulate air (HEPA) resistance

filter.

Class I Biosafety Cabinet

- It is an open-fronted type of cabinet with

negative pressure (ventilated cabinets).

- Unfiltered room air enters through the front

(open face) and does not pass through a HEPA

filter before reaching the work surface.

- The exhaust air, however, does pass through a

HEPA filter, protecting the environment.

- It is used for working with biosafety levels (BSL)

2 and 3 agents.

Class II Biosafety Cabinet

- Class II Type A2 BSC: the most commonly

used biosafety cabinet in clinical

microbiology laboratories

- It provides protection to the personnel,

product, and environment by using

HEPA-filtered vertical laminar airflow over

the work surface and HEPA-filtered

exhaust air

- Suitable for handling BSL-2 and BSL-3

agents

Class III Biosafety Cabinet

- A gas-tight, totally enclosed cabinet that provides the

highest level of protection for the worker, product,

and environment

- Air entering the cabinet is passed through HEPA

filters to prevent contamination of materials. Exhaust

air is also HEPA-filtered (often through two HEPA

filters in series) or incinerated

- All materials are manipulated through attached

rubber gloves (hence the term "glove box")

- Used for handling biosafety level 4 (BSL-4) pathogens,

including those that are highly infectious, lethal, and

for which no vaccine or treatment exists

OSHA’s Pathogen Regulations

- Refers primarily to the Occupational Safety and Health Administration’s

Bloodborne Pathogens Standard (29 CFR 1910.1030).

- This regulation is designed to protect workers from health hazards related

to exposure to blood and other potentially infectious materials (OPIM) in

the workplace.

- To reduce occupational exposure to bloodborne pathogens (BBPs), including:

● HIV (Human Immunodeficiency Virus)

● HBV (Hepatitis B Virus)

● HCV (Hepatitis C Virus) ...and other pathogens found in blood and OPIM.