Surgical Suite » Laser Hazards

Employees are exposed to lasers used in healthcare facilities during diagnostic, cosmetic, preventive, and therapeutic applications, including surgical applications. Lasers used in these applications are incorporated into an apparatus, which includes:

  1. A delivery system to direct the output of the laser,
  2. A power supply with laser control and calibration functions,
  3. Mechanical housing with interlocks, and
  4. Associated liquids and gases if required for the operation of the laser.

When lasers are present in a healthcare environment, professionals must be prepared to address safety issues for both the staff and patient. Safe use of these systems requires an understanding of the engineering, training, and administrative requirements for all elements of a healthcare system as well as the risks associated with use of lasers.

All medical lasers are regulated, and federal regulations require manufacturers to classify the medical laser system based primarily on its ability to cause damage to the eye and skin. This classification must be indicated on the laser system’s label ranging from Class 1 (no hazard) to Class 4 (serious hazard).

Nearly all treatment laser products used in surgery are Class 4 as they are designed to deliver laser radiation for the purpose of altering biological tissue.

Hazards

The following provides information regarding the use of lasers:

Note: Class 2 and higher must have the laser radiation warning label

The Food and Drug Administration regulates all medical lasers under regulations issued under the Medical Device Amendments of 1976 to the Food, Drug, and Cosmetics Act [21 CFR Parts 800-1299], and the Performance Standards for Light Emitting Products [21 CFR Part 1040].

Federal regulations require manufacturers to classify medical laser systems based primarily on their ability to cause damage to the eye and skin. This classification must be indicated on the laser system’s label.

In addition, the American National Standard Institute (ANSI) Z136 series of laser safety standards covers lasers in medical settings, and provides guidance for the safe use of lasers for diagnostic, cosmetic, preventive and therapeutic applications in healthcare facilities through ANSI Z136.3 (2011) - Safe Use of Lasers in Health Care. ANSI assigns the following classes to lasers:

Class 1

A Class 1 laser system is considered to be incapable of producing damaging radiation levels during normal operation, and is exempt from any control measures or other forms of surveillance. Although some Class 1 lasers emit very weak, non-hazardous beams, most Class 1 laser systems incorporate "embedded" higher-power lasers, which can be accessed only if important safety features such as interlocks are defeated or deliberately bypassed as is sometimes done during servicing. In this case, the system temporarily reverts back to the original laser classification (requiring special safety procedures). NOTE: Products which have been previously classified as Class 2a should be treated the same as Class 1.

Class 1M

A Class 1M laser system is considered to be incapable of producing hazardous exposure conditions during normal operation unless the beam is viewed with an optical instrument such as an eye-loupe (diverging beam) or a telescope (collimated beam), and is exempt from any control measures other than to prevent potentially hazardous optically aided viewing; and is exempt from other forms of surveillance.

Class 2

A Class 2 laser system emits in the visible portion of the spectrum (400-700 nm), and eye protection is normally afforded by the aversion response. The aversion response is the closure of the eyelid, eye movement, pupillary constriction, or movement of the head to avoid an exposure to a bright light stimulant. The aversion response to a bright visible laser source is assumed to limit the exposure of the retina to 0.25 seconds or less.

Class 2M

A Class 2M laser system emits in the visible portion of the spectrum (400-700 nm), and eye protection is normally afforded by the human aversion response for unaided viewing. However, Class 2M is potentially hazardous if viewed with certain optical aids.

Class 3R

A Class 3R laser system is potentially hazardous under some direct and specular reflection (shiny or mirror-like) viewing conditions if the eye is appropriately focused and stable, but the probability of an actual injury is small. This laser will not pose either a fire hazard or diffuse reflection hazard. NOTE: Products which have been previously classified as Class 3a should be treated the same as Class 3R.

Class 3B

A Class 3B laser system may be hazardous under direct and specular viewing conditions, but is normally not a diffuse reflection or fire hazard.

Class 4

A Class 4 laser system is a hazard to the eye and skin from the direct beam, and may pose a diffuse reflection or fire hazard, and may also produce laser-generated airborne contaminants and hazardous plasma radiation.

In operations using lasers that vaporize tissue through disruption of cells, laser generated airborne contaminants (LGAC) result as an airborne hazard requiring appropriate management. Analysis of these contaminants produced during laser surgical procedures has shown the presence of:

  • Gaseous toxic compounds;
  • Bio-aerosols;
  • Dead and live cellular material; and
  • Viruses.

In orthopedics, dentistry, plastic surgery and other fields, it is also possible to generate particulates and metal fumes. At certain concentrations some of the LGAC may cause ocular and upper respiratory tract irritation, have unpleasant odors, create visual problems for the user, and have been shown to have mutagenic and carcinogenic potential. It has been shown that laser smoke production is a function of increased irradiance levels. Therefore, laser surgical procedures requiring high irradiance levels are more likely to produce LGAC.

Figure 3. Goggles Figure 4. Class 2 Laser Sign stating: "Caution. Laser Radiation. Do not stare into beam."  Figure 5. Class 4 Laser Sign stating: "Danger. Laser Radiation. Avoid eye or skin exposure to direct or scattered radiation."

The American National Standard Institute (ANSI) Z136 series of laser safety standards covers lasers in medical settings and provides guidance for the safe use of lasers for diagnostic, cosmetic, preventative and therapeutic applications in healthcare facilities. These guidelines are considered to be the foundation for safe practice in the healthcare industry and include recognized controls and work practices such as the following:

  • Control airborne contaminants by the use of local exhaust ventilation, respiratory protection or a combination of both. [ANSI Z136.3]
  • Use laser protective eyewear that provides adequate protection against the specific laser wavelengths being used. All laser eyewear must be marked with Optical Density (OD) and laser wavelength.
  • Display warning signs conspicuously on all doors entering the Laser Treatment Controlled Area (LTCA), so as to warn those entering the area of laser use. Cover or remove warning signs when the laser is not in use.
  • Ensure that maintenance on lasers and laser systems is performed only by facility-authorized technicians trained in laser service.
  • Provide local exhaust ventilation with a smoke evacuator or a suction system with an in-line filter to reduce levels in laser applications.
  • Use an appropriate filter or barrier, that reduces any transmitted laser radiation to levels below the applicable Maximum Permissible Exposure (MPE) level, for all facility windows (exterior or interior) or entryways located within the Nominal Hazard Zone (NHZ) of a and laser system. The NHZ describes the space around the laser within which the level of direct, reflected, or scattered radiation during normal operation exceeds the MPE.
  • Ensure that proper alignment and calibration techniques are followed prior to using the laser system.
  • Use skin protection if repeated exposures are anticipated at exposure levels at or near the applicable MPE limits for the skin.
  • Provide detailed training in laser safety for healthcare personnel using, or working in the presence of, Class 3B and Class 4 healthcare laser systems. Document all training activities and retain documentation on file. Present laser safety training to the following healthcare personnel: [ANSI Z136.3]
    1. Laser Safety Officer (LSO);
    2. Users;
    3. Laser technical support staff; and
    4. Nurses and allied health personnel.
  • Ensure credentialing of staff using laser systems. Each medical specialty has evolved its own procedures for bringing in new techniques and new surgical procedures. In all cases, ensure that the laser user uses the laser for its intended purpose within the user's scope of practice, training and experience. Also ensure that all credentialing processes require training in the safe clinical use of the laser, as well as the maintenance of a safe environment in compliance with defined standards, and local, state and Federal requirements.

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