Hazards:


   Laser produces a very intense beam of light in which, when absorbed, could cause the material on contact to become deformed or damaged. Or, in simpler English, the laser makes a very, very intense(high frequency-above) beam of light, so if anyone of anything comes in contact with that type of laser, they/it could end up damaged or injured quite badly. As many may have heard, the most popular type of accident with lasers is when the beam somehow gets pointed to the eye and someone goes literally blind- or almost blind. This is because, obviously, that the eye is almost always vulnerable and the cornea doesn’t have any protection what so ever to shield it from the burn of the laser, so once the laser hits one’s eye, there’s no hope in actually hoping to have full vision as one would have had before.
           

                                                      
be careful or else your eyes could end up like this  :                                                                                                      

    There is also such a thing, as in the sci-fi movies, when beams of laser, reflected correctly, can start a fire or burn one’s skin, though it is a very rare occasion in which it would actually happen outside scientists’ labs.

Safety:

The safest thing would probably not to handle lasers with such an intense beam at all, but when the time calls for it, there is always a safety law to back it up. According to a law that the U.S. passed, all laser products sold in the USA since August 1979 has to be qualified by the producer that it meets safety standards and must have a label in which indicates that the component if indeed safe and not too prone to hazards. In other words, according to the US law, the company or person who produces such things must make sure that it is safe and put a seal on it which shows the consumers that the product has been certified and checked to be sure that it is safe.

 
Classification:

    Scientists, after much experimenting and tests, have put all the different levels of laser beams into one set of classification, also known as the MPE’s, Maximum Permissible Exposures,kind of like different degrees of burns, except for the fact that lasers' damages re not as big and noticeable but nonetheless the same amount of injury nd damage. By setting this, people can be able to know how intense or strong the laser actually is before using or testing it. The levels are set up as followed:

Class 1

    A Class 1 laser is thought to be relatively safe, from a medical researchers point of view, though that’s still not enough reason to be playing around with one. This class includes all laser or laser systems which cannot produce levels of optical radiation, in which  above the ezposure limits for the eye under any exposure conditions inherent in the design of the laser product. There may be a more hazardous laser embedded in the  enclosure of a Class 1 product, but no harmful radiation can escape the enlosure.

Class 2

    Class 2 lasers can emit beams that are visible to the naked eye, or can be seen without any type of help what so ever from machines, such as microscopes or such alike. If one were to stare right into a Class 2 laser, which if highly not recommended, it would be not only dazzling to stare at fro so long, but also hazardous if exposed to the eye for more than 0.25 seconds, which is not a lot of time. A quick glance, however, would not be considered injurious, because of the fact that it has less danger than what the MPE’s rate. Nevertheless, looking at a Class 2 laser for extended periods can prove very damaging.  Seeing thtat all laser is damaging to the eye, there was actually no point in saying all that, but for research, it proves necessary.

Class 3

    A laser of Class 3 can emit an type of beam in which cn be seen and not seen, in other words, it can emit a laser of an wavelength and in turn, almost any type. However, despite this  A Class 3 laser or laser system can emit any wavelength, but it cannot produce a diffuse (not mirror-like) reflection hazard unless focused or viewed for extended periods at close range. It is also not considered a fire hazard or serious skin hazard. Any continuous wave (CW) laser that is not Class 1 or Class 2 is a Class 3 device if its output power is 0.5 or less. Since the output beam of such a laser is definitely hazardous for intrabeam viewing, control measures center on eliminating this possibility.

Class 4

   A Class 4 laser or laser system is any that exeeds the output limits (Accisible Emission Limits, AEL's) of a Class 3 device. As would be expected, these lasers may be either a fire or skin hazard or a diffuse reflection hazard. Very stringent control measures are required for a Class 4 laser or laser system.