Lab safety copy.ppt
- 1. Presented by: Dr. Nesreen mostafa Lecturer of clinical pathology
- 2. • Introduction • Definitions • Lab acquired infections 1. Risk factors 2. Rout of infection 3. Pathogens • Biosafety levels • Laboratory safety programme 1. Laboratory practices & techniques. 2. Safety equipment. 3. Laboratory design.
- 3. Laboratories Dealing with Infectious Materials: 1.Microbiologic- al laboratory 2. Biochemistry laboratory 3. Hematology laboratory 4. Pathology laboratory Hazardous Materials: Physical (e.g., needles, glass). Chemical (e.g., acids, alkalis). Biological agents (e.g., clinical samples, microbial cultures) Biohazardous Materials include: Infectious organisms (bacteria, fungi, parasites, prions, rickettsiae, viruses, etc.). Human or primate tissues, fluids, cells, or cell culture.
- 4. Laboratory-acquired infections (LAIs) are all infections acquired through laboratory activities which start from collection & transport of specimens till the result is issued. Laboratory biosafety Guidelines developed to protect workers in microbiological and medical labs through engineering controls, management policies, work practices
- 5. Risk factors for LAIs: 1. Sample volume 2. Sample microbial load 3. virulence of the organism 4. Infectious dose of the organism 5. Route of exposure 6. Workload 7. Adherence to safety regulations 8. Host factors (e.g., pregnancy, immunosuppression). 9. Knowledge & experience of the worker. 10. Attitude & habits.
- 6. ROUTES OF EXPOSURE LAB. PRACTICE INHALATION Procedures that produce aerosols: -Centrifugation -Spills & splashes -Mixing, vortexing -Opening sample containers INGESTION -Mouth pipetting -Eating, drinking, smoking, nail biting at work -Splashes into mouth INOCULATION -Needlesticks -Cuts from sharp objects -Animal bites CONTAMINATION OF SKIN & MUCOUS MEMBRANES -Splashes onto m.m. of eyes, nose, mouth -Contact of blood with skin having small lesions
- 7. PATHOGEN (INFECTION) BACTERIA COMMENTS -Brucella (brucellosis) The most frequently reported bacterial LAI. All species are highly contagious in the lab. -Mycobacterium tuberculosis (pulmonary T.B.) Infectious dose is very low. -Neisseria meningitidis (meningitis) Infrequently reported. Infects by aerosol formation. -Stool pathogens: *Salmonella & Shigella The most commonly reported gastrointestinal LAIs. Infection occurs by ingestion. Infectious dose is smaller than other enteric pathogens.
- 8. PATHOGEN (INFECTION) BACTERIA (Continued) COMMENTS -Stool pathogens (Continued): *Escherichia coli O157:H7 *Campylobacter jejuni (enteritis) Infectious dose is low. -Rickettsiae: e.g., Coxiella burnetti (Q fever) The 2nd most commonly reported LIA in the world. Aerosol transmission. Labs with animals are at risk. -Chlamydia psittaci & trachomatis Only sporadic cases are reported. Cause pneumonitis & lymphadenitis.
- 9. PATHOGEN (INFECTION) COMMENTS VIRUSES -Blood-borne pathogens: Hepatitis B virus Hepatitis C virus HIV -Hemorragic fever viruses: Transmitted by: parenteral inoculation, percutaneous contact with infectious material (blood & other body fluids) in the presence of skin lesions, exposure of mucous membranes. Highly infectious by aerosol. Cause fatal disease. The most virulent agents are: Ebola, Lassa, Marburg viruses. FUNGI -Blastomyces dermatitidis -Histoplasma capsulatum -Coccidioides immitis -Sporothrix schenckii Infections originate from inhalation of spores. Cutaneous infections may result from accidental inoculation. PROTOZOA -Toxoplasma gondii -Others: Malaria, leishmania, trypanosomes The most frequently observed parasitic LAIs. In labs with animals, by needlestick injuries.
- 10. DEFINITION: *These are guidelines which describe appropriate containment equipment, facilities & procedures based on dividing microorganisms into groups according to modes of transmission, availability of vaccine/or treatment & seriousness of the possible infection. *Four biosafety levels (BSLs) are described. *With class 1 agents, hazards are minimal; class 4 agents require maximum containment.
- 11. BSL-1: -Lowest level of containment. -For agents which cause no disease in healthy adults (e.g., Bacillus subtilis) -Work can be done on open bench. -Only standard practices are required. BSL-2: -For moderate risk agents transmitted by ingestion, percutaneous or mucous membrane exposure not via aerosols (e.g., Salmonella spp, hepatitis B virus). -Ordinary work: on open bench + primary barriers (face protection, gloves,…). -If splashes are expected: biosafety cabinets must be used.
- 12. • Standard practices required : – frequent handwashing – door that can be kept closed when working; – limits on access to the lab space when working ; – no smoking, eating, drinking, storage of food in laboratory; – care to minimize splashes and actions that may create aerosols (tiny droplets); – decontamination of work surfaces after every use after any spills – decontamination of laboratory wastes; – use of mechanical pipettes only (no mouth pipetting); – "sharps" precautions, including special containers for disposing of needles and other sharp objects; – maintenance of insect/rodent control program; – use of personal protective equipment (lab coats, latex gloves, eye protection or face shields
- 13. BSL-3: -For hazardous microorganisms transmitted primarily by aerosols (e.g., M. tuberculosis, C. burnetti). -All procedures are done only in biosafety cabinets . -Specific requirements for lab. e.g., suitable ventilation system. BSL-4: -For agents which cause life-threatening disease, transmitted by aerosol, with no available vaccine or therapy (e.g., hemorrhagic fever viruses). -Work is done only in biosafety cabinets: (class III) or (class II + personnel wearing full-body, air-supplied, positive-pressure suits) . -The facility is totally isolated from other laboratories & has a specialized ventilation and waste management system..
- 15. Comprises 3 aspects: 1. Laboratory practices & techniques. 2. Safety equipment. 3. Laboratory design. GOAL: To reduce or eliminate exposure of lab. Workers (LWs) and the environment to potentially hazardous agents. Primary containment: involves protection of personnel and the immediate environment. Secondary containment: involves protection of the environment external to the laboratory.
- 16. -Hand hygiene: How ? Hands must be washed with antiseptic soap or rubbed with alcohol-based gel When? *After removing gloves. *After handling contaminated materials or surfaces. *Before leaving the lab.
- 17. -Protective laboratory clothing: *Gloves (well-fitting latex) must be worn for all procedures that involve direct skin contact with biohazardous material & are removed when task is completed, when soiled/torn, before leaving the lab. *Eye & face protection are used when splashes expected. *Footwear must be with closed toes & heels. *Clothing properly fastened & not worn in non-lab areas. *Open wounds & cuts should be covered with water- proof dressings.
- 19. -Waste disposal: •Sharp objects e.g., needles, scalpels, capillary tubes, prick instrument, broken slides, broken contaminated glass, slide covers,… disposed of in “sharp containers” Needles should not be recapped or separated from the syringe. They should be disposed as one piece in the sharp container.
- 20. - Potentially infectious waste (contaminated tubes, used gloves, used swabs, disposable used petri dishes,…) should be disposed of immediately at the time of production in special colored bags with biohazardous label. - Ordinary waste (paper packs, empty boxes, food remnants, …) which resembles house waste is disposed of in normal bags (black). - Contaminated wastes may be sterilized by autoclaving then disposed of with the ordinary wastes.
- 21. -Decontaminate work surfaces & equipment daily & after spills. -Spills of blood, body fluids or chemicals are considered lab accidents. -Small spills are removed with a gloved hand using a small dry absorbing material, then the area is disinfected using a material soaked with conc. chlorine-containing disinfectant. -Large spills are covered with a large absorbing material on which a chlorine-containing disinfectant is poured, left for 10-15 min then removed. Area is then disinfected as mentioned above.
- 22. -Do NOT eat, drink, apply cosmetics or smoke in the lab. -Do NOT store food in refrigerators used for lab. Purposes. - Long hair and large veils should be tied back -Consider all blood & blood-contaminated materials “infected”. - Pipetting: *Use disposable plastic pipettes. *Avoid mouth pipetting & use instead mechanical pipetting devices.
- 23. a. Biosafety cabinets. b. Fume hood. c. Safety centrifuges. d. Sharp containers.
- 24. a. Biosafety cabinets (BSCs) -Biosafety cabinets protect: 1. Laboratory worker & environment from contaminated spashes & aerosols. 2. Samples & media from being contaminated. - BSCs must be tested & certified on a regular basis.
- 25. Class I BSCs -Negative pressure. -Open front. -Designed for work with agents of low to moderate risk (BSL-1 or -2).
- 27. Class II BSCs -Negative pressure. -Open front. HEPA-filtered vertical laminar airflow. -Part of the filtered air is recirculated & part is got rid of. -Designed for work with agents of BSL-2 or -3.
- 29. المحيط الهواء الملوث الهواء مروره بعد الهواء فلتر خالل HEPA
- 30. HEPA HEPA المحيط الهواء الملوث الهواء فلتر خالل مروره بعد الهواء HEPA HEPA فلتر
- 31. Class III BSCs -Totally enclosed cabinets. -Accessible only through glove ports. -Provides the highest possible level of protection. -Designed for work with agents of BSL-3 or -4).
- 32. نوع III المحيط الهواء الملوث الهواء فلتر خالل مروره بعد الهواء HEPA HEPA فلتر
- 34. b. Fume hood: Laboratory fume hoods serve to control exposure to toxic, offensive or flammable vapors, gases and aerosols. The laboratory fume hood is a type of local exhaust ventilation system (engineering control).
- 35. • A typical fume hood is a cabinet with a moveable front sash (window) made out of safety glass. A properly used and properly functioning fume hood exhausts hazardous gases, dusts, mists, and vapors from a confined location and helps protect workers from inhalation exposure
- 37. • c. Safety centrifuge cups prevent release of infectious agents that can be transmitted during centrifugation via aerosols & splashes
- 38. Basic safety procedures for centrifuges: *Keep lid closed while centrifuge is operating. *If centrifuge vibrates, stop immediately & check load balances. *Clean & disinfect after each use.
- 39. d. Sharp containers: *Puncture-resistant. *Leak-proof. *Readily accessible. *Appropriately labeled. *NOT filled to more than ¾ of their maximum capacity to avoid accidents from overfilling. *Once filled, should be securely & irreversibly closed.
- 40. -Laboratory design depends on the type of microorganisms processed in the lab. -Most isolates recovered from clinical samples are of BSL 1 or 2, thus most clinical laboratories must fulfill the following criteria: *A space separated from public areas by locked doors with signs. *Work surfaces should be nonabsorptive/scratch, stain, chemical & heat resistant.
- 41. *Windows prevent entrance of flying insects. *Ready access to hand-washing sinks (preferably operated without hands). *Emergency showers & eye-washing stations available. *Air supply of 100% outside air with no recirculation.
- 42. The safety program should also include: *Surveillance for LAIs esp. HBV, HIV & T.B. *Vaccination plans e.g. HBV vaccine, diphteria/tetanus toxoid, meningococcal vaccine, ... *All lab. safety procedures & guidelines should be written and available to all staff. *Material safety data sheets (MSDS) for all chemicals and microorganisms must be available. •Lab. Personnel must receive proper training and orientation. *Staff members should know the location of emergency equipment & routes for evacuation in case of fire or accidents.