Rig 3 Laser Alignment (Class 4 UV Laser) Standard Operating Procedure (SOP)
INTRODUCTION
Lasers are optical devices that amplify light by means of stimulated emission of radiation. The output of a laser is electromagnetic radiation (light) of highly amplified and focused energy. A class 4 laser, like our DPSS UV laser, represents the highest classification of laser in terms of power output (ranging typically 500mW and greater). This class of laser is commonly used in biological imaging for deep tissue stimulation of fluorescent markers and photolytic chemical uncaging, but is also used in industrial applications to cut metal and glass.
SPECIFIC HAZARDS
Direct and indirect exposure to the beam of a class 4 laser can cause significant tissue damage to eyes or skin within fractions of a second (i.e., faster than typical human reaction times). Such eye and skin injuries can also occur as the result of reflective or diffuse beam exposures and require careful planning to prevent accidental exposures.
The class 4 laser may represent a potential fire hazard as it is capable of generating sufficient heat to ignite combustible materials.
GUIDELINES FOR ALIGNMENT AND USE IN CLASS 4 CONFIGURATION
To control for the specific hazards listed above, the following guidelines should be observed during use and alignment:
1. Be sure that all preliminary procedures for the use and standard operation of the laser have been implemented before performing alignments or calibrating optics.
2. Use of eyewear graded for UV wavelength (preferably 190-540nm) and with optical density (OD) of 5+ or better, should be worn at all times during the use or alignment of the laser in class 4 configuration. The Rig 3 room will have two pair of LaserShields model BD1#33 on hand at all times for this purpose.
3. All watches, rings, badges and any other reflective items and jewelry should be removed from the wrists, neck, head and chest before any alignment activity or laser activation begins. Whenever possible, non-reflective tools, such as screwdrivers with a matte finish, should be used.
4. During alignment or laser activation, the Rig 3 door will be additionally marked with a clearly visible warning sign reading “Laser Alignment (or Testing) in Progress” and the door should be locked from the inside.
5. Only trained and authorized lab personnel are permitted in the room during laser use and alignment. Furthermore, the number of personnel present during alignment should be minimized when possible.
6. Two trained lab personnel (“buddy” system) should perform alignments together to ensure the presence of assistance in the event of an emergency.
7. All tools, electonics, and combustible materials not necessary to alignment should be removed from the immediate work area.
8. Whenever possible, lower power test laser pointers (class 3a and 3b) will be used to simulate the laser path while adjusting optics.
9. Following completion of alignment, the Principle Investigator or appropriate representative will perform a safety review of the laser setup.
During laser activation:
1. The person who turns on the laser is responsible for the beam, including knowing its path, ensuring that personnel are using eyewear, and giving an audible warning signal.
2. The laser base will be kept horizontal during operation and maintained at optical bench level well below average eye level. The beam path will also be enclosed at the earliest practical time with opaque, non-reflective material casing.
3. A phosphor card (stored in the Rig 3 room) will be used to locate the beam path if invisible.
4. Locate potential specular reflections of the beam and block them near their source before turning on the laser. Do the same for any unexpected reflections that appear following activation.
5. Whenever possible, the class 4 beam will be reduced to the minimum possible power output.
6. Beam shutters will be utilized to block the beam any time it is not immediately needed.
7. Appropriately rated beam blocks will be placed behind optics (e.g. adjustable mirrors) to terminate beams that might miss their target during alignment.
TRAINING REQUIREMENTS
Before working with any laser equipment in any capacity, all authorized lab members should attend a general laser safety training session with Robin Bell (bell@brandeis.edu), the university’s radiation safety officer. Additional training specific to the laser will be issued by the lab members Jason Osik or Steve Van Hooser.
EMERGENCY PROCEDURES
IN THE EVENT OF ACCIDENTAL BEAM EXPOSURE:
1. Immediately shut down the beam by either pressing the “STANDBY” button, or by turning the key switch to the “OFF” position.
2. If exposure is a burn to the skin, first aid should follow the same critieria for burns from any heat source based on severity:
· Remove jewelry, including watches, from the burn area
· Expose the burn area, but avoid removing clothes stuck to the skin
· Immerse burn in cold water for at least 10 minutes, or apply ice packs
· Cover first and second degree burns with a moist bandage; apply dry compresses to third degree burns
· Do not burst blisters, which form a natural barrier against infection
3. Report the accident to your supervisor
4. If burn is serious, contact university emergency services at 781-736-3333
5. If exposure is to the eyes, send the victim to Brandeis Health Center or contact emergency personnel. Be sure to inform medical personnel of the characteristics of the laser and the distance of the victim from the laser.
IN THE EVENT OF ACCIDENTAL COMBUSTION:
1. Immediately shut down the beam by either pressing the “STANDBY” button, or by turning the key switch to the “OFF” position.
2. Only if the fire is low grade and you are comfortable doing so, attempt to extinguish the flame. Otherwise, do not endanger yourself or others attempting to put out the flame.
3. If you choose to use the ABC type extinguisher stored with the laser, be aware that the physical and chemical characteristics of the material emitted in the spray can damage sensitive laboratory equipment. Judge your use of the extinguisher accordingly.
4. If the flame cannot be extinguished, immediately contact university public safety at 781-736-3333 and evacuate the area.
REFERENCES
safety.uchicago.edu/pp/laser, University of Chicago 2010.
www.ms.ornel.gov, Materials Science & Technology Division, Oak Ridge National Laboratory, 2010.
www.parn.org.uk , Professional Associations Research Network, Laboratory Safety FAQ, 2008.
DPSS Laser Series 3500-SMPS User’s Manual (780-023 Rev. E), 2008.