READ CAREFULLY BEFORE USING A LASER

Classes of Lasers

To provide a basis for laser safety requirements, all lasers and laser systems and/or devices in the U.S. are classified into one of several classes. Corresponding labels are affixed to the laser or laser system. Understanding the laser classification is a fundamental prerequisite for any discussion of laser safety.

These laser classes are contained both in ANSI Z136.1 and in the Federal Laser Products Performance lasers is provided by the manufacturer. For custom-built and modified lasers, the LSO can provide the proper classification.

A third standard is the IEC standard. This standard, different from both ANSI and the Federal Laser Products Performance Standard, has been implemented by the European Union. It is also described below.

The following sections describe the hazard classification scheme adopted by the ANSI Z136 committee. Some special notes reflect variation between ANSI Z136.1 and the Laser Products Performance Standard (21 CFR 1040.10).

Class 1 Lasers

Class 1 lasers do not emit harmful levels of radiation and are, therefore, exempt from control measures. As a matter of good practice, unnecessary exposure to Class 1 laser light should be avoided.

Class 2 Lasers

Class 2 lasers emit accessible laser light in the visible region and are capable of creating eye damage through chronic exposure. In general, the human eye will blink within 0.25 second when exposed to Class 2 laser light. This blink reflex provides adequate protection. It is possible, however, to overcome the blink reflex and to stare into a Class 2 laser long enough to cause damage to the eye. Class 2 lasers have power levels less than 1 mW. Class 2 lasers are commonly found in alignment applications.

Class 2a Lasers (Not Used by ANSI Z136)

Class 2a lasers are special-purpose lasers not intended for prolonged viewing. Their power output is less than 1 mW. This class of lasers causes injury only when viewed directly for more than 1,000 seconds. Many bar-code readers fall into this category.

Class 3a Lasers (ANSI Z136.1)

Class 3a lasers and laser systems are normally not hazardous when viewed momentarily with the naked eye, but they pose severe eye hazards when viewed through optical instruments (e.g., microscopes and binoculars). Class 3a lasers have power levels of 1–5 mW.

Class 3a Lasers (FDA/CDRH)

These are the same as the ANSI Z136.1 Class 3a lasers, except that they must be in the visible portion of the spectrum and have power levels of 1–5 mW.

Class 3b Lasers

Class 3b laser radiation will cause injury upon direct viewing of the beam and specular reflections. The power output of Class 3b lasers is 5–500 mW continuous wave (cw), or less than 10 J/cm2 for a 1/4-second pulsed system. The specific control measures for Class 3b lasers described in this chapter must be implemented.

Class 4 Lasers

Class 4 lasers include all lasers with power levels greater than 500 mW cw or greater than 10 J/cm2 for a 1/4-second pulsed system. They pose eye hazards, skin hazards, and fire hazards. Viewing of the beam and of specular reflections or exposure to diffuse reflections can cause eye and skin injuries. All of the control measures in this document must be implemented.

IEC Classification Scheme

Class 1

Laser products that are safe under every conceivable condition of use

Class 1M

Laser products that are safe for the unaided eye with no added optical elements, and are safe under every reasonably foreseeable viewing condition without optical aids. Labeling would state, "Do not view directly with hand-held magnifiers or microscopes" for a diverging beam, and "Do not view directly with binoculars or telescope" for collimated beams.

Class 2

Limited to visible lasers (400–700 nm) safe to view within 0.25 second due to the aversion response. They are safe to view even with optical aids.

Class 2M

Limited to visible lasers that are safe to view by the unaided eye for 0.25 second. They are unsafe under some viewing conditions with optical aids.

Class 3R

Laser products that are marginally unsafe for intrabeam viewing (similar to ANSI Class 3a).

Class 3B

Laser products that are unsafe for intrabeam viewing. Same as ANSI Class 3b.
 

Transcript from  Lawrence Berkeley National Laboratory (Berkeley Lab) website and you can see more clicking on the following link:
http://www.lbl.gov/ehs/pub3000/CH16.html

BY USING THE LASER YOU AGREE THAT YOU HAVE READ ALL ABOVE AND AGREE WITH EVERYTHING WRITTEN BELOW
- You are over 18 years of age .
- You understand that these laser components that are mentioned above are dangerous when not properly assembled into a finished product.
- You will use these components as an OEM product and properly incorporate them into a finished product.
- You will use these laser diodes in a safe and responsible manner and for a legal purpose.
- You are legally responsible for the use of these components, improper use of these components or their end products.
- You are legally responsible for any injury to anybody resulting from the use of or assembly of these components or their finished products.
- You Accept this Laser as an OEM COMPONENT for integration in a system of YOUR OWN design and will be legally responsible from any and all LIABILITIES
Our Laser Diodes and Modules are designed solely as an OEM component for incorporation into the customer's end products. Therefore, this laser does not comply with the appropriate requirements of FDA 21CFR, section 1040.10 and 1040.11 for complete laser products.

STEINER & MARTINS, INC.