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Non Ionizing Radiation Safety and Chemical Safety SK Dua, Ph. D., CHP, CLSO Bill Youngblut, MS, CIH, CSP Environmental Health & Safety Florida International University Conceptualization Get EH&S, and engineering professionals involved as early as possible. Before submitting grant proposal or budget. Help identify and correct potential problems. Time line issues for local, state, and federal safety & environmental permits. – Avoid budget over runs – Avoid construction delays – Avoid process startup delays – Avoid fines Conceptualization… EH&S professionals involved should include: Safety Engineer Fire Safety Environmental (Air, Water & Waste) Radiation & Laser Safety Officer Industrial Hygienist Disposal & Recycle Environmental impact of battery and printed circuit board manufacturer and disposal. Heavy Metals (Lead, Silver, Gold, Platinum, Mercury, Copper) Solders, Flux Solder & Flux residues – Rinse water residue – Airborne concentration levels in manufacturing – Contain metals, resin – Consult manufacturer or MSDS for more information Batteries: Acids, lead Circuit board substrate: Beryllium ORGANIZATION CHART: MANAGEMENT: IONIZING AND NON-IONIZING RADIATION PROGRAM Senior Management: Vice President of Research Alternate: Director, EH&S Chairperson Radiation/Laser Safety Committee Safety Committee Establish operating policies, practices and procedures for compliance with the regulations. Review proposals, reports, procedures, conduct program audit. Communicate with RSO/LSO Radiation/Laser Safety Officer Reports to Dir., EH&S, Manages day-to-day program activities, Submits proposals, reports, procedures, reviews to Committee for approval/comments/vote Authorized users and workers Comply with posting and labeling requirements Follow safe practices and procedures Ionizing vs. Non-ionizing Radiation Ionizing Radiation – Higher energy electromagnetic waves (X- gamma) or particles (alpha beta) – High enough energy to pull electron from orbit Non-ionizing Radiation – Lower energy EM waves (laser, radio & TV broadcasting, cell phone, pagers, satellite, Microwave ovens, Power lines, Physical therapy- RF Diathermy – Not enough energy to pull electron from orbit, but can excite the electron Laser Components Laser Devices The laser is a device, which produces a very intense and very narrow (collimated) beam of electromagnetic radiation in the wavelength range 180 nm to 1 mm. Laser devices are ranked by class (1, 2, 3a, 3b and 4) according to their energy or power, and hence, their potential to cause injury. Laser radiation exposure can cause injury to: – Eye and skin Laser Warning Signs and Symbols American National Standards Institute International Electro Chemical Society Posting Warning Signs The entrance door shall have laser label with warning sign and laser class. The entrance door shall have hazard identification chart. The entrance door to the laser lab shall have lighted sign, “Laser in Use” whenever laser is turned on. Work Management can arrange to install the signage. Expenses will be borne by the Department/PI. Whenever laser is in use visual or audible warning devices should be turned on. Laser Safety- Controls Engineering Controls Administrative and Procedural Protective Equipment Engineering Controls Protective Housings (All Classes). Interlocks on Removable Protective Housings (All Classes) Key Control (Class 3b or Class 4) Viewing Windows, Display Screens, and Collecting Optics Remote Interlock Connector (Class 3b or Class 4) Beam Stop or Attenuator (Class 3b or Class 4) Warning Signs Administrative and Procedural Controls Post laser warning signs. Standard Operating Procedures (Class 3b or Class 4). SOPs for class 4 shall be developed, documented, reviewed and approved by Laser Safety Officer Output Emission Limitations Education and Training (Class 3b, or Class 4). The laser shall have emergency shut off. It is preferred to have shut off both near the laser device and at a remote console Administrative and Procedural Controls… Laser Beams Laser beams, direct/diffused shall be properly shielded to prevent inadvertent exposure of eyes or skin. All beam alignments shall be performed at low power (class 1). When the lab door is opened the laser should either be shut off or reduced in power or should be adequately shielded to prevent injury. Laser beams should not be at eye level- while standing or seated. Procedures – On-line Laser Safety Training – Laser Purchasing Procedure – Laser Registration with the State – Laser Laboratory Inspection – Laser Research Proposal Review – Eye Examination – Beam Alignment – Laser Operation Protective Equipment Suitable personal protective equipment, e.g., eye protection glasses suitable for the laser power/energy and wavelength, will be used. Beam shutters/shields shall be available where required. Bioeffects Photochemical vs. Thermal Limits Shorter wavelengths in the visible (400 to 600 nm) can produce chemical changes in retinal tissue destroying its functionality. These changes can occur for longer exposures and at lower levels than thermal burns. Photochemical sensitivity decreases with increasing wavelength. Both limits must be evaluated in classifying a product in the photochemical wavelength range. Laboratory Accidents 60% of laser accidents in the research setting happen during laser alignment, beam manipulation Almost all without the user wearing laser protective eyewear Why? Open beams - During alignment - Flexibility in calibration procedures - Experimental set up changes Some famous quotes from the laser users who do not comply with the safety measures “Don’t insult my intelligence.” “I’ll get it the work done one way or the other.” “That can’t happen to me.” “15 years working with lasers and I haven’t had an accident yet.” “Nothing bad will happen.” “Hey I have two eyes” “Trust me” “I know where the beam is” All incidents should be investigated to enhance the environment, safety, health and quality, prevent recurrence, and reduce the possibility of severe trends Laser Safety- Non-beam Hazards Electrical Laser Generated Air Contaminants (LGAC) Collateral and Plasma Radiation Optical Radiation Fire Explosion Compressed Gases Laser Dyes All non-beam hazards shall be identified and prevented. Electrical Hazard Many laser systems use high voltage and high current electrical power. Reports of electrical shock, both fatal and non-fatal can be found for research, medical, and industrial settings. Preventative measures No Fluids used or placed near the laser system Label the laser system with the electrical rating, frequency and watts Proper grounding for metal parts of the laser system Assume all floors are conductive when working with high voltage Electrical Hazard- Preventative measures… Provide such safety devices- rubber gloves and insulating mats Combustible components of the electrical circuit are short circuit tested Avoid Contact with electrical components. Capacitors that can contain electrical charge even after the laser is powered off. Discharge, short and ground each capacitor before accessing the capacitor area Inspect capacitor containers for deformities or leaks Avoid wearing rings, metallic watchbands and other metallic objects when working near high voltage environment Prevent explosions in filament lamps and high pressure arc lamps Electrical Hazard- Preventative measures… Include in regular inspection verification of the integrity of electrical cords, plugs, and foot pedals Only qualified persons authorized to perform service activities access laser’s internal components Do not work alone When possible, only use one hand when working on a circuit Develop and implement lockout/tagout procedures Laser Generated Airborne Contaminants (LGAC) High power lasers (beam irradiance of hundreds of W/cm2) upon interaction with substrates may generate aerosols, gases and vapors, called LGAC. These contaminants may adversely affect health, environment and materials, and must be controlled. LGAC are controlled by using proper air filtration systems. Local exhaust ventilation systems can effectively capture the air contaminants in close proximity to an emission source. General ventilation is used to reduce the concentration of the air contaminants not removed by the LEV. Collateral and Plasma Radiation X-radiation may be generated from electronic components of the laser system, e.g., high voltage vacuum tubes (> 15 kV) and laser-metal interactions. Plasma emission created during laser-material interaction may contain sufficient UV and blue light. Optical Radiation Hazard There are several sources of optical radiation emissions which can cause eye injury and skin burn: Ultraviolet light from discharge tubes Visible / infrared light from pumping lamps Blue light and UV emissions from interactions between high power laser beam and target material Intense bright light and thermal emissions from laser welding Preventative measures: Shield the optical radiation by proper enclosure. Wear suitable personal protective equipment to protect eyes and skin. Fire Hazard A fire can occur when a laser beam (direct or reflected) strikes a combustible material such as paper products, plastic, rubber, human tissues, human hair and skin treated with acetone and alcohol-based preparations. The risk of fire is much greater in oxygen-rich atmospheres. The three components required for a fire to start are: 1) a combustible material 2) an oxidizing agent 3) a source of ignition Keep these components physically separated from each other. Explosion Hazards Sources: High pressure arc lamps, filament lamps and capacitor banks in laser equipment - Enclose in housing Metal dust collected in ventilation systems - Maintain properly Compressed Gases Hazardous gases (Cl2, F, HCl HF) are used in laser applications. Develop SOP for safe handling. Safety problems with compressed gases: Free standing cylinders not isolated from personnel No remote shut off valve Incorrect labeling of cylinders & gas lines Gases of different categories not stored separately No leak testing - Loose gas line fittings Laser Dyes and Solvents These complex fluorescent organic compounds in solution with solvents form a lasing medium. Concerns: Dye Powders – Carcinogens (benzo(a)pyrene); – Toxic Little or no toxicity data Before mixing with solvent, concentrated dye powder inhalation or skin contact hazard Dye Solvents – chemical and physical hazards: – Transport dissolved substances through the skin – Flammable (Chlorobenzene, Cyclohexane, Methanol) – Toxic (Benzonitrile, Dioxane, Dimethylformaldehyde) – Carcinogenic (Chloroform, Dichloroethane, Tetrahydrofuran) Caution Radiofrequency Energy Electromagnetic Fields Whenever there is electricity, there are: electric and magnetic fields, these are invisible lines of force created by the electric charges. Electric field (unit V/m) exists near an appliance that is plugged into and electrical outlet (even if it is turned off). Increases in strength with voltage. Magnetic field (unit A/m, Gauss or Tesla) results from the flow of current through wires or electrical devices and increases as the strength of current increases. Electromagnetic Fields… Electric field can be easily shielded or weakened by conducting objects Magnetic fields are not weakened and pass through most materials and are most difficult to shield. Both fields weaken with distance from the source. Line sources of magnetic Field 1/d2 Point sources of magnetic Field 1/d3 Maximum Permissible Exposure Limits Power line magnetic lines are ELF rage of spectrum
"Non ionizing Radiation Safety"