Everyone loves laser pointers, whether it is to play with your cat, or to help you highlight an educational or business PowerPoint presentation, they are both fun and convenient. Laser pointers (also known as laser pens) are small handheld devices that have a battery or other power source, and a laser diode that emits a fine coherent low power beam of visible light. They come with varying power levels, with some as low as 5mw and others up to 500mW and over. They also come with varying colors mainly green, blue, red, violet and yellow.
work with laser safety goggles
photo via laserpointerpro.com
However, it is important to understand the dangers that are associated with the use of these devices. Lasers and especially High Power Laser Pointer, are capable of causing eye injuries, and other dangerous situations due to distraction. They are classified into various classes (by the Center for Devices and Radiological Health) based on their power levels, and the injury they are likely to cause.The First Class of laser products is usually lasers that are encased hence ensuring that there is no biological hazard to the users. The laser system is also usually interlocked to prevent it from being exposed. If you have this kind of laser, it is pertinent that you do not remove the casing, and in case it does come off, then ensure to read and understand the power warnings. This applies to both larger laser pointers, and smaller pointers such as those in the DVD/CD or Blu-ray recorders and players.
The Second Class of pointers are those up to a power of 1 milliwatt or less. They are not necessarily optically dangerous, because the eye reflex is able to prevent any ocular damage. This means that the person will automatically blink or move their head to protect the eye. These lasers will not be able to cause any damage in this time, but if a person looks at it for extended periods of time, eye damage can occur. They also will not cause any skin or fire hazards. They usually come with a yellow caution label.
The Third class of laser products (IIIa) are products of below 5mW but above 1mW. These lasers are capable of casing spot blindness in the right conditions. They are also capable of causing eye other kinds of injuries. This kind of lasers come with a Danger label on the equipment, and a laser emission indicator that shows you when it is in operation. They also come with a power switch that is key operated, to prevent use by unauthorized persons. It however does not have any known skin or fire hazards.
The fourth class (IIIb) are lasers from between 5 and 500 mW. These lasers are instant eye hazards and will definitely cause eye damage. They will usualy come with a key switch to prevent unauthorized use, a 3-5 second delay to allow the operator to move from the beam path after the power is applied, and a laser emission indicator. They also come with a mechanical shutter to switch off the beam when in use. They are also skin hazards, and skin may burn especially at the higher levels. If concentrated on certain materials, this lasers are likely to start a fire and are hence considered a fire hazard. They will usually come with a red DANGER label.
The fifth class of products is high powered laser pointers which are above 500 mW. This lasers will always cause eye damage, and can burn materials and skin upon contact. These are the most dangerous kinds and will usually come with all the warning signs of the fourth class of lasers. If you are using a 2000mW laser pointer, it is important to note that a reflected beam will be as dangerous as a primary beam. In fact, at such power levels, these lasers are capable of blasting human sided holes through reinforced steel.
If you will be using a laser pointer, there are some basic safety regulations that you need to keep in mind.
Never shine a laser (regardless of the power level) on another person at any time.
Normal lasers of under 5mW are not harmful, but even then caution should be exercised when using them.
The green lasers emit infrared light which is harmful. Avoid looking down into the laser barrel whether it is on or off. The infrared rays are usually not visible to the eye, which causes them to be an even greater hazard. This is because your eye will not react in the same way as it would to visible light, and the eye reflex will not protect your eyes. The intensity of the beam fries your retina and you will not realize it until you have lost your sight.
Any laser above 50mW can and WILL cause damage to eyes. Lasers above 80mW will cause damage that may take time to recover.
At power levels of above 100mW permanent eye damage will occur, and above 300 mW, it will be instantaneous.
If you shine a laser at an aircraft or a moving automobile, you can be charged with a federal crime, and you may be jailed. However, even if you are not caught, common decency dictates that you should not shine light on a person if they are driving, or operating any dangerous equipment. You are likely to cause them to cause an accident which may be fatal.
If you shine a laser at a cop or any other law enforcement person, there is a likelihood that you might get shot.
Avoid using lasers normal or High Powered laser pointers in areas with heavy traffic such ass airports or train stations. It may be perceived as a threat and could cause panic or distract the drivers or pilots.
Using high powered laser pointers such as a 2000mW laser in a public demonstration, requires special permission and special equipment should be used to ensure that the public are at a safe distance.
Irresponsible use of a laser pointer is generally frowned upon by society and may lead to legislation on its use.
There are various other classifications of laser pointers, especially high powered laser pointers, and although the regulations are not standardized, there is regulation that prevents their use especially when they are likely to cause harm. Remember that high powered lasers are not toys and should only be used by authorized persons and special care should be taken.