Non ionizing Radiation Safety

Document Sample
Non ionizing Radiation Safety Powered By Docstoc
					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

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:12
posted:10/13/2011
language:English
pages:58