1. Laser Safety

2. Purpose of this Program:
To increase awareness in laser safety

3. History
American National Standard for Safe Use of Lasers Z (ANSI Z )
American National Standard for Safe Use of Lasers in Education Institutions (ANSI Z )

4. Program Outline What is a laser? Laser Incidents/Accidents
Laser hazards – Eye, Skin, Chemical and Electrical Hazards
Safety Guidelines/Controls

5. What is a laser? – Block Diagram

6. What is a laser?
LASER- Light Amplification by Stimulated Emission of Radiation
Laser light differs from ordinary light in 3 ways:
Monochromatic
Directional
Coherent
Lasers can pose more of a hazard than ordinary light because the can focus a lot of energy onto a small area

7. Laser Accidents The times when accidents happen: During alignment
During maintenance
Under stress or pressure
When tired
Failure to pay attention to work

8. Laser Accidents by Percentage
Activities
Non beam
In use exposure
Incorrect eyewear
Alignment

9. Exposure Incidents
If the incident causes injury or could potentially have caused injury, the person or persons who have received an exposure should inform their supervisor who should call immediately
University Safety and Assurances will assist in an investigation of the accident

10. Laser Classifications
Class 1 – Exempt lasers or laser systems that cannot, under normal operation conditions, produce a hazard
Example: Compact disc player

11. Laser Classifications
Class 2 – Low power visible lasers or lasers systems which, because of normal human aversion responses, do not normally present a hazard, but may present some potential for hazard if viewed directly for extended periods of time
Example – most alignment lasers should be Class 2

12. Laser Classifications
Class 3a – A laser that normally would not produce a hazard if viewed for only momentary periods with the unaided eye.
Example – HeNe up to 5 mW total power

13. Laser Classifications
Class 3b – Lasers or laser systems that can produce a hazard if viewed directly.
Example – HeNe from 5 mW up to 500 mW total power

14. Laser Classifications
Class 4 – Lasers that can produce a hazard not only from direct reflection, but also from diffuse reflection. In addition such lasers may produce fire hazards and skin hazards
Example – High power Argon Ion lasers

15. Laser Exposure Limits -- Terms
MPE (Maximum Permissible Exposure)
The highest laser energy to which the eye or skin can be exposed for a given laser
NHZ (Nominal Hazard Zone)
Area within which the MPE is equal to or exceeded

16. Laser Hazard – Nature of Light
The output of the laser will help to determine its interaction with a target. The greater the power, the more energy that will be delivered to the target and the greater the possibility of injury.

17. Laser Hazard – Eye

18. Laser Hazard – Eye Both acute and chronic exposure
Corneal, optical nerve, retinal injury, lens damage
Vision damage is usually severe and may result in blindness
Direct viewing of the laser source and its reflections should be avoided
Eye tissues are susceptible to various forms of laser radiation and should be protected by appropriate eye protection

19. Laser Hazard – Skin
Burns, skin cancer, and acceleration of skin aging are possible from exposure to laser radiation
Chronic exposure can cause increased pigmentation
Photosensitive reactions may occur

20. Laser Hazard – Hazardous Materials
Reaction induced by lasers can release hazardous particulate and gaseous products
Ignition of gases or fumes from the laser
Engineering controls (i.e. ventilation) should be used
All hazardous materials must be properly used, stored and controlled
Obtain MSDS for all materials
Wear lab coat, eye protection and gloves

21. Laser Hazard – Dyes and Solutions
Vary greatly in toxicity
Some are flammable
All dyes must be treated as hazardous chemicals
Obtain MSDS for all dyes and solvents
Use and store all dyes and solvents in accordance with the University’s Chemical Hygiene Plan
Wear lab coat, eye protection and gloves

22. Laser Hazard – Electrical Hazards
Lethal electrical hazards are particularly present when high-power laser systems are used
Fire Hazard

23. Precautions for all lasers in Preventing Electrical Shock
Learn CPR rescue procedures for high voltage shock
Avoid wearing rings, metallic watchbands and other metallic objects
When possible, use only one hand in working on a circuit or control device
Never handle electrical equipment when hands, feet or body are wet, perspiring or when standing on wet floor

24. General Safety Practices While Working
Wear appropriate protective eyewear
Use minimum power/energy required for project
Enclose beam as much as possible
Reduce laser output with shutters/attenuators
Terminate laser beam with beam trap
Use diffuse reflective screens, remote viewing systems, etc., during alignment if possible
Remove unnecessary objects from vicinity of laser
Locate beam at waist level or below. Keep beam path away from eye level (sitting or standing)
Don’t put your body parts (particularly your eyes) in the beam path!

25. Great Housekeeping

26. Overview of Safety Controls for Class 3b and 4 lasers
Registration – Complete on-line form
Laser Classifications
Training of operators and personnel working on or near lasers
Periodic safety inspections
Access Restrictions
Posting and labeling
Medical Monitoring
Protective eyewear and clothing
Administrative/Engineering Controls

27. Training of operators and personnel working on or near lasers
Required for all Class 3b and 4 users.
Complete on-line training course, read manual, and complete and submit on-line exam

28. Laser Audits
Periodic Safety Inspections
Laser Audit Form

29. Access Restrictions
Only allow trained individuals, wearing appropriate personal protective equipment, into the Nominal Hazard Zone

30. Medical Monitoring
All Class 3b and 4 laser users must receive a baseline eye exam prior to using lasers and laser systems

31. Access Restriction
Master Switch – Class 3b and 4 lasers must have a master switch that is controlled by a key or coded access. Access by key or code must only be provided to trained operators
Interlocked Entry or laser barrier screen/curtain
Posting and labeling of rooms and equipment, to include a warning light in the hallway or access entrance

32. PPE Control Measures Appropriate eyewear
Eyewear must be for the appropriate laser wavelength, attenuate the beam to safe levels, yet be comfortable enough to wear
Gloves
Special Clothing

33. Administrative Safety Practices
Standard operating procedures
Authorized personnel only in vicinity of laser (Access Restriction)
Designate NHZ for Class 3b and 4 lasers
Address non-beam hazards

34. Standard Operating Procedures
All Class 3b and 4 lasers are to have written Standard Operating Procedures (SOP). SOP’s will contain the following information:
System Information (description, location, class)
General Information (equipment owner, inventory control
Operating procedures
Alignment Procedures

35. Standard Operating Procedures (continued)
Maintenance/services procedures
Hazards Summary (beam, non-beam)
The nominal hazard zone (NHZ) for the above procedures
Required Control Measures (access controls, system controls, personnel controls, emergency instructions)
Protective eyewear and other personal protective equipment

36. Nominal Hazard Zone

37. Engineering Safety Practices
Beam enclosures whenever practical. This will significantly reduce the need for other engineering or administrative controls
Activation warning system outside the control area
Window and door barriers (typically curtains at the doorways)
Ventilation
Panic button

38. Curtains

39. Ventilation
Local or other exhaust ventilation may be needed depending upon your operation due to vapors or dusts that may be emitted.

40. Panic Button Panic Button
(remote interlock connector) Class 4= required
Class 3b= should be used

41. Laser Safety Signs and Labels
Signs & Labels

42. Illuminated Sign

43. Notice – Laser Alignment/Repair

44. Class 2 – Caution

45. Class 3a -- Caution

46. Class 3a -- Danger

47. Class 3b -- Danger

49. Resource
Laser Institute of America (LIA)
Phone: LASER
Web:
LIA guide for the selection of laser eye protection (78 pages)

50. For additional information:
Click to view these resources:
Laser Safety Web Page
Laser Safety Manual
UWM Laser Safety Officer
Phone:

51. Acknowledgements
Some photos courtesy of Samuel M. Goldwasser, Drexel University