BIOHAZARD-types and management presentation

BIOHAZARD-medical

1. HAZARDS IN CLINICAL BIOCHEMISTRY SREELAKSHMI.S AND NANDITA.S JR PATHOLOGY

2. Hazards in clinical biochemistry arise from: From dangerous chemicals From infected specimens Faulty apparatus and instruments

3. Hazards from dangerous chemicals 1. Direct contact With skin With lip and mouth With the oesophagus and stomach 2.Damage to lungs from inhaling vapors 3.Toxic effects of substances absorbed from lungs,GIT or skin

4. Aromatic compounds –spillage should be cleaned immediately Concentrated acids and toxic organic solvents those in largest quantity ---Keep only sufficient of these in the lab When the contents have been used-rinse well with water ----dispose the container

5. Corrosive chemicals Nitric , sulphuric and hydrochloric acid Sodium and potassium hydroxide Phenol

6. When pouring from such bottles hold them firmly in both hands Place the receiving vessel in the sink Always add contents slowly to water or aqueous solution preferably while cooling and stirring If measured quantity of corrosive liquid is needed use a safety pipette, burette or a measuring cylinder according to quantity

7. Toxic chemicals Scheduled poisons(cyanides and barbiturates) Keep locked in a cupboard or small store Measure these reagents by safety pipette,burette or measuring cylinder Mouth pipetting forbidden While discarding cyanide down a sink do so with good flow of water to avoid any harmful effects Avoid simultaneous disposal of cyanide and acids which can liberate hydrogen cyanide Cyanide antidote kit to be kept in drug cupboard

8. 2. Organic solvent a) Benzene----Toxic to bone marrow b) Carbon tetrachloride-----Toxic to liver When using these, carry out procedures, including distillation in a fume cupboard with adequate extraction Do not pipette toxic solvents orally Keep the minimum needed for daily working in lab Place bottles containing them in a cool place out of direct sunlight

9. 3. Mercury Mercury loses vapor into atmosphere if exposed at ordinary temperature Store in thick walled jars in cool place Spillage should be cleared immediately

10. 4.Toxic gases Natural gas ,carbon dioxide, phosgene and compressed air Carbon dioxide -----only likely reach hazardous concentration in solid form(dry ice) in a poorly ventilated room Phosgene------May be formed in stored chloroform residues and may be liberated during distillation. Rate of formation can be reduced by adding little ethanol and storage in dark bottles Compressed air------Never direct a jet of compressed air at skin since severe tissue injury may occur and there is possibility of fatal air embolism

11. Carcinogens Aromatic amines- benzidine and ortho -toluidine Precautions Keep them in well closed bottles labelled carcinogenic Avoid contact with skin. Wear rubber or plastic gloves while handling which are afterwards well washed under cold running water Accidental skin contact------wash in cold running water for several minutes After use rinse glassware thoroughly in cold water After handling with full precautions wash hands in cold water and with soap

12. Explosive and flammable chemicals Explosives Perchloric acid------only use when there is no alternative test procedure Picric acid(when dry explodes on percussion)-------store underwater in a container closed by a cork Ether(kept in clear bottles exposed to sunlight can form peroxide)---kept in dark bottles and before distilling shake with freshly prepared ferrous hydroxide Chloroform and acetone(may combine and form chloracetone )-----keep them separately in clearly labelled containers Nitric oxide (when combined with alcoholic solution cause exothermic reaction)----extreme care should be taken

13. Flammable chemicals Flammable and combustible liquids, which are used in numerous routine procedures, are among the most hazardous materials in the clinical chemistry laboratory because of possible fire or explosion They are classified according to flash point, which is the temperature at which sufficient vapor is given off to form an ignitable mixture with air. A flammable liquid has a flash point below 37.8°C (100°F) and combustible liquids, by definition, have a flash point at or above 37.8°C (100°F). Some commonly used flammable and combustible solvents are acetone, benzene, ethanol, heptane, isopropanol, methanol, toluene, and xylene.

14. Flammable solvents, must be collected in approved containers and segregated. If practical, solvents such as xylene and acetone may be filtered or redistilled for reuse. If recycling is not feasible, disposal arrangements should be made by specifically trained personnel. Flammable material also can be burned in specially designed incinerators with afterburners and scrubbers to remove toxic products of combustion. If flammable gas are used with compressed air or oxygen, fit the gasline with a non-return valve

15. Fire hazards Every laboratory should have the necessary equipment to extinguish or confine a fire in the laboratory and to extinguish a fire on the clothing of an individual. Easy access to safety showers is essential. A safety shower should have a pull chain attached to the wall at a convenient height or hanging down from the shower head; the chain should have a large ring attached so that the shower may be easily  activated.   Fire blankets for smothering fire on clothing should be available in an easily accessible wall-mounted case .

16. The location of this equipment and locations of fire alarms and maps of evacuation routes are dictated by the local fire marshal Various types of fire extinguishers are available. The type to use depends on the type of fire.

17. Because it is impractical to have several types of fire extinguishers present in every area, dry chemical fire extinguishers are among the best all purpose extinguishers for laboratory areas. An extinguisher should be provided near every laboratory door and, in a large laboratory , at the end of the room opposite the door. Everyone in the laboratory should be instructed in the use of these extinguishers and any other available firefighting equipment . All fire extinguishers should be tested by qualified personnel at intervals specified by the manufacturer

18. Infection hazard Exposure to infectious agents results from (1) accidental puncture with needles (2) spraying of infectious materials by a syringe or spilling and splattering of these materials on bench tops or floors (3) centrifuge accidents and (4) cuts or scratches from contaminated vessels. Any unfixed tissue, including blood slides, must also be treated as potentially infectious material.

19. The National Institute for Occupational Safety and Health (NIOSH), a functional unit of the CDC, has prepared and widely distributed a document entitled Universal Precautions that specifies how U.S. clinical laboratories should handle infectious agents. In general, it mandates that clinical laboratories treat all human blood and other potentially infectious materials as if they were known to contain infectious agents, such as hepatitis B virus (HBV),HIV, and other blood borne pathogens. These requirements apply to all specimens of (1) blood, (2) serum, (3) plasma, (4) blood products, (5) vaginal secretions, (6) semen, (7)cerebrospinal fluid, (8) synovial fluid, and (9) concentrated HBV or HIV viruses.

20. Universal precautions also specify that barrier protection must be used by laboratory workers to prevent skin and mucous membrane contamination from specimens. These barriers, also known as PPE, include (1) gloves (2) gowns (3) laboratory coats (4) face shields or mask and eye protection (5) mouthpieces (6) resuscitation bags (7) pocket masks, and (8) other ventilator devices .

21. New products for increasing employee protection against needle sticks include an array of novel containers for sharps(e.g., needles, scalpels, glass) and biological safety disposal bags and needle sheaths that may be closed following venipuncture without physically touching the needle or the sheath.

22. Electrical Hazards Electrical wires or connections are potential shock or fire hazards. Worn wires on all electrical equipment should be replaced immediately, and all equipment should be grounded using three-prong plugs Use of extension cords is prohibited Electrical equipment and connections should not be handled with wet hands, nor should electrical equipment be used after liquid has been spilled on it. The equipment must be turned off immediately and dried thoroughly. In case of a wet or malfunctioning electrical instrument that is used by several people, the plug should be pulled and a note cautioning coworkers against use should be left on the instrument .

23. Radioactive Waste The manner of use and disposal of isotopes depends on the type of waste (soluble or insoluble), its level of radioactivity, and the radiotoxicity and half-life of the isotopes involved. The radiation safety officer should always be consulted about policies dealing with radioactive waste disposal. Many clinical laboratories transfer radioactive materials to a licensed receiver for disposal .

24. A radiation safety policy should include environmental and personnel protection. All areas where radioactive materials are used or stored must be posted with caution signs, and traffic in these areas should be restricted to essential personnel only. Regular and systematic monitoring must be emphasized, and decontamination of laboratory equipment, glassware, and work areas should be scheduled as part of routine procedures. Records must be maintained as to the quantity of radioactive material on hand as well as the quantity that is disposed. A Nuclear Regulatory Commission (NRC) License is required if the total amount of radioactive material exceeds a certain level. The laboratory safety officer must consult with the institutional safety officer about these requirements .

25. Radiation monitors must be evaluated regularly to detect degree of exposure for the laboratory employee. Non-ionizing forms of radiation are also a concern in the clinical laboratory. Equipment often emits a variety of wavelengths of electromagnetic radiation that must be protected against through engineered shielding or use of PPE

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