Laser safety is important because the laser produces electromagnetic energy in wavelengths at or near the visible portion of the energy spectrum, Figure 1. The wavelength of a laser is the deciding factor as to how and where that energy will be absorbed.
The far infrared energy wavelength is easily absorbed by water, the same water that we are made up of. And just as your microwave heats food, the first cells in your body tissue contain water which will absorb the energy and get hot.
The good news, the common CO² laser accounts for only 1/8 of total laser accidents. However, the Nd: Yag laser waves travel much deeper into the body, penetrating further into body tissue before the heating process begins. In this range, your internal organs are at risk.
The Laser Safety Officer
Any individual with the authority and responsibility to monitor and enforce the control of laser hazards, this safety position is called the Laser Safety Officer (LSO), per ANSI Z136.1 (1993), “For the safe use of lasers” and describes that position as:
The Laser Safety Officer (LSO)
Should have training in the following areas:
1) Laser operations and theories
2) Biological effects of the laser beam
3) Exposure limits
4) Medical surveillance
5) Control measures
6) Laser safety audits
7) Calculating the nominal hazard zones
Whenever light passes through an optical element ‘stray’ reflections can be generated that can affect your eyes or burn skin; wear your protective devices. Protective eye glasses, area barriers, and filters are not always required but… damage can be done by light to both your skin and eyes.
Special note that eye tissue is more sensitive than skin!
The amount of eye damage is dependent on laser’s wavelength. Absorption of light in various parts of the eyes can cause irreversible damage!
Note the different ranges of microwave radiation and where they are absorbed within the eye, figure 3.
As an operator, if Safe Laser Practices are your goal, here are a few that should never be done:
Operating while tired
Operating under the influence of alcohol, etc.
Having a macho attitude
Using unskilled workers
Repairing or aligning a laser you are not trained for it
Laser safety – Non-beam Hazards
These include Ignition, Noise, High voltage, Gase, and liquids. There are many other “non-beam” hazards.
The laser accident statistics for 1996 / 1997 show that the leading cause of all laser related accidents is shock or electrocution. Never attempt any maintenance or repairs without first being trained!
However, with high voltages in the area there is increased chance of electrocution. Having the proper knowledge to work with high voltage electricity is a must! Stay away from, and never open the power box unless you are an electrician. Click here for a printable full size copy of the Electric Shock Response poster, figure 4.
The basic rules for working in any shop are:
1) Never work alone!
2) Always have someone nearby that is current with modern techniques of resuscitation.
3) Always wear all safety equipment, especially safety glasses.
4) Never attempt any maintenance or repairs without first being trained!
5) Always remove all metal or conductive materials from your person:
a) Watches, rings, bracelets and belt buckles.
b) Remove all pens, screw drivers, etc., from your pockets.
6) Never point anything conductive at a power circuit.
7) Compressed gas is a concern for your eyes.
8) The laser can be a major source of airborne contaminants.
9) Review the MSDS sheets for information on fumes !
The following video is courtesy of Asma LLC. titled: Laser Programming And Safety.
Laser Programming and Safety
Courtesy of Asma LLC
“In a word… it’s all about control and paying attention!