Society of Exploration Geopysicists Benha University student chapter
The American University in Cairo Laboratory Safety Biological Hazards
Introduction • Biological hazards, are unlike chemicals, in that they can reproduce. • Exposure to a small number of organisms can create serious problems. • There are many different ways you can be exposed to biological hazards when working in the laboratory. • Types of agent, its life cycle, and how it can be transmitted.
Recognition of Biological Hazards
Biological Hazards • Biological agents are living things, or substances produced by living things, that can cause illness or disease in humans. • Biological agents include: Bacteria, viruses, and fungi as well as larger organisms such as parasites and plants.
Routes of Entry and Transmission • Biological agents enter the body by inhalation, by ingestion or by absorption through the skin. • Inhalation is the most common route of entry. • Once inside the body, infectious agents can multiply and be passed from one person to another. • The route of transmission may be direct or indirect.
Direct Transmission of Infectious Agents • Direct transmission takes place when there is physical contact between an infected and noninfected person. • It can also occur if there is a projection of droplets into the mucous membranes of the eye, nose or mouth. (cough or sneeze) • It might also occur if a person is injected or punctured with an infected needle or other sharp object which is infected.
Indirect Transmission • May occur when infectious agents attach themselves to materials or objects such as food and water or cooking and eating utensils. • Transmitted by an insect. • Transmitted through the air and are hazardous if inhaled.
Evaluating Biohazards
Biosafety Levels • There are four biosafety levels (BSLs), each based on the degree of hazard, type of agent, and modes of transmission.
Biosafety Levels (BSLs) • BSL-1: • No known or minimal potential hazard of exposure to infectious agents. • Practices, safety equipment, and facilities are appropriate for undergraduate and secondary educational training and teaching laboratories.
Biosafety level 2 • Moderate potential hazard (low risk) of exposure to infectious agents. • Practices, equipment, and facilities are applicable to clinical, diagnostic, teaching and other facilities in which work is done with the broad spectrum of indigenous moderate risk agents present in the community and associated with human disease of varying severity.
Biosafety level 3 • Practices, safety equipment, and facilities are applicable to clinical, diagnostic, teaching, research, or production facilities in which work is done with indigenous or exotic agents with a potential for respiratory transmission, and which may cause serious and potentially lethal infection. • Moderate risk of exposure to agents that can cause serious or potentially lethal disease.
Biosafety Level 4 • High individual risk of exposure to dangerous or exotic agents which cause life-threatening disease. • Practices, safety equipment, and facilities are applicable for work with dangerous and exotic agents which pose a high individual risk of life-threatening disease, which may be transmitted via the aerosol route, and for which there in no available vaccine or therapy.
Waste 1- Biohazardous Waste • Human or animal specimen cultures from medical and pathological labs, cultures and stocks of infectious agents from research labs. • Waste from production of bacteria, viruses or the use of spores, discarded live and attenuated vaccines, culture dishes and contaminated devices used to transfer, and mix cultures.
Biohazardous Waste • Human surgery specimens or tissues removed at surgery. • Animal parts, tissues, fluids, or carcasses suspected of being contaminated with infectious agents. • Waste which contains recognizable fluid blood, fluid blood products, containers, or equipment containing fluid blood or blood from animals, having been infected with diseases that are highly communcable to humans.
Continued • Medical waste • Pharmaceutical waste • Sharps waste
Control CONTAINMENT • It is a safe methods for managing infectious agents in the laboratory environment where they are being handled or maintained. • The purpose of containment is to reduce or eliminate exposure of lab workers, other persons, and the outside environment to potentially hazardous agents.
Elements of Containment • 1- Laboratory practice and techniques. • 2- Safety Equipment (Primary Barriers). • 3- Facility Design (Secondary Barriers).
Laboratory Practices and Techniques • Persons working with infectious agents or potentially infected materials must be aware of potential hazards, and trained in the practices and techniques required for handling materials Safely. • Biosafety Manual for each lab. • Comptent person must direct lab activities.
Safety Equipment Primary Barriers • • • •
Biological Safety Cabinets. Enclosed containers (safety centrifuge cup) PPE (gloves, coats, gown, shoe covers, boots, respirators, face shields, safety glasses and goggles.)
Facility Design Secondary Barriers • Separation of the laboratory work area from public access. • Availability of decontamination facilities (autoclave) • Handwashing facilities • Special Ventilation systems • Airlocks (double door – entrance).
Biological Safety Cabinets • Biological safety cabinets (BSCs) are designed to protect you from splashes and aerosols that are contaminated with microbes, bacteria, and viruses that can infect you. • There are three major classes of BSCs. • Class I BSCs: Protect you and the environment. • Class II BSCs: protect you and the environment, and they also protect the materials from contamination from outside.
Continue • Class III BSCs: • Give the highest available protection to you, the environment, and the material.
Class I BSC • This is a ventilated cabinet for personnel protection with an unrecirculated inward airflow away from the operator. • This unit should be fitted with HEPA filter to protect the environment from discharged agents.
BSC I
BSC II • This is a ventilated cabinet for personnel, product and environmental protection which provides inward air flow and HEPAfiltered supply and exhaust air.
BSC II • Class II cabinets may be of use with low to moderate risk biological agents, minute quantities of toxic chemicals, and trace quantities of radionuclides.
BSC II
BSC III • A class III cabinet is a totally enclosed ventilated cabinet which is gas-tight, and maintained under negative air pressure. • The supply air is HEPAFiltered and the exhaust air has two HEPA filters in serious. • Work is performed in the cabinet by the use of attached rubber gloves.
BSC III
Guidelines for Working in Biological Safety Cabinets • Make sure cabinet is tested and certified before use. • Avoid exposure to cabinet’s UV light. • Turn air on and keep it running, allow air to filter for few minutes before starting work. • Make sure everything needed for the experiment is inside the cabinet. • Do not block cabinet’s air grilles with material and equipment.
Continue • Segregate contaminated items (I.e. clean items to the left, contaminated items to the right.) to avoid mix-ups. • Waste collection containers such as small bio-hazardous waste bags, should be placed inside cabinet to avoid bringing contaminated items outside of cabinet, and out into the lab.
Continue • Avoid frequent and rapid arm movement in and out of cabinet, to prevent disturbing airflow and bringing contaminants out to the lab. • Always keep spill absorbent towels and decontaminating solution close by or in the cabinet. • Prevent extended reaching, place materials as close as possible.
Continue • Perform your work at least 6 inches (15 cm) into the BSC to maintain optimal air flow containment for material and personal protection. • Always assume a proper posture. Use only adjustable chair or stool with built-in foot and armrest.
Safe Laboratory Practices • Do not eat, drink or store food in the laboratory. Store food in designated areas only. • Do not apply cosmetics in the laboratory. • Never mouth pipette, always use appropriate pipetting devices. • Remove contaminated clothing immediately after it comes in contact with infectious material.
Continue • Always wear appropriate attire in the laboratory. No matter how small is the task at hand, always use assigned protective clothing and equipment. • Always wash hands after any laboratory activity, after removal of gloves or other protective clothing, and immediately after contact with infectious material.
Continue • Manipulate all infectious materials carefully to avoid spills and production of aerosols and droplets. Aerosol generating procedures must be performed in appropriate enclosures (Fume hoods, BSC). • Decontaminate work surfaces before use, after use and immediately after spills of infectious material. Use a 70% ethanol to wipe cabinet’s work surfaces down, prior to and after the completion of each work session. Decontaminate with a 10% chlorine bleach solution if necessary, especially after spills.
Continue • Always use disposable glass or plastic ware. If nondisposable items must be used, make sure to disinfect items before cleaning. (use a 10% chlorine bleach solution) • Restrict the use of needles, scalpels, syringes, razor blades and other sharps to those procedures for which there are no other alternatives. If they must be used, avoid self-inoculation; do not re-sheath or try to remove used needles; dispose of whole assembly in a leak-proof, and puncture-resistant container immediately after use. Never leave sharps unattended on any work surface.
Continue • Discard all contaminated disposable items in autoclave bags. All infectious waste including normal cells, culture media and microorganisms must be autoclaved before disposal in the normal trash. (See infectious waste disposal procedure). • Keep accurate inventories and inform Environmental Health and Safety Office of any infectious (biological hazardous) material you acquire, including storage location.
Continue • Heat resistant gloves must be available and used when unloading autoclave.