• What is a "laser plume"?
• What is the content of a plume?
• Are there any health hazards associated with laser plumes?
• How can the plume be controlled?
• How can the plume be controlled by ventilation?
• What safe work practices should be used?
• What types of personal protection should workers wear?

What is a "laser plume"?

Lasers and electrocautery are used for surgery to vaporize, coagulate, and cut tissue. The vapours, smoke, and particulate debris produced during these surgical procedures are called laser plumes.

What is the content of a plume?

Laser plume may contain carcinogens, mutagens, irritants, and fine dusts. Plumes may also contain bioaerosols, viruses and cancer cells, blood fragments, and bacteria spores depending on the type of the procedure. They also contain carbon monoxide, polyaromatic hydrocarbons, and various toxic gases. Plumes may contain chemicals such as formaldehyde, hydrogen cyanide, acrolein, and benzene.

Are there any health hazards associated with laser plumes?

Medical staff and patients in hospitals and clinics can be at risk from exposure to laser plumes.

Health symptoms resulting from laser plume exposure include eye, nose, and throat irritation, nausea, vomiting, nasal congestion, chest tightness, abdominal cramping, general flu-like symptoms, and fatigue. These are short-term health effects usually lasting 24 to 48 hours. At present there is no knowledge of potential chronic health effects from long-term exposure to laser plume. However, carcinogens, mutagens and irritants have been found in laser plumes.

The human papilloma virus (HPV) DNA has also been found in the plume of tissue vaporized with carbon dioxide (CO₂) lasers. Suspected hazards associated with the laser plumes are the transmission of viable viruses such as human immunodeficiency virus (HIV).

How can the plume be controlled?

Contaminants generated by lasers and electrosurgical units can be controlled by:

• Ventilation.
• Safe work practices.
• Personal protective equipment.

Please see table below for more information.

* Toxic Chemicals can include: benzene, formaldehyde, acrolein, aldehydes, polycyclic aromatic hydrocarbons, cyanides, and methane hydrogen cyanide.

How can the plume be controlled by ventilation?

General room ventilation (dilution ventilation) is not sufficient to remove air contaminants. Two types of local exhaust ventilation can be used to efficiently remove the laser plume contaminants.

A) Smoke Evacuation System

Smoke evacuators are mobile units consisting of a vacuum pump, filter, hose, and an inlet nozzle placed close to the source of the smoke. The suitable airflow speed of the smoke evacuator for controlling the airborne fumes will depend on the rate of smoke generation.

A mechanical smoke evacuator system with a high-efficiency particulate air (HEPA) or an ultra-low penetration air (ULPA) filter should be used to capture the plume. The air suction ability of filters is significantly reduced when the filter has reached its capacity. Each smoke evacuator should have the capability to detect (e.g., pressure drop) if a filter is getting overload. The nozzle of the evacuator should be placed to capture as much of the plume as possible (within 2 - 5 cm of the lasing site).

In addition to the Üsmoke evacuation equipment there should also be appropriate equipment for aspirating fluids.

B) Local exhaust systems

Local exhaust systems remove the laser plume before it reaches people. Hospitals often use the wall suction system for this purpose. In order to be effective the exhaust system must include the following features:

• in-line filters to prevent clogging of the exhaust tubes;
• exhaust air ventilated outside the building (and away from air inlets) to prevent recirculation;
• blower located on the rooftop at the end of the line in order to maintain negative pressure in the ductwork to prevent leakage of contaminated exhaust air.

What safe work practices should be used?

There should be a laser safety program in place and all staff who must work with or near the laser unit should receive:

• training on proper procedures for the safe use of equipment,
• instructions about how to keep equipment in good working order, and
• education about possible health and safety hazards.

The Canadian Safety Association (CSA) Standard Z386-01 "Laser Safety in Health Care Facilities" specifies that medical facilities that use Class 3 or 4 lasers shall have a laser safety officer (LSO) and a laser safety committee (LSC) to ensure that laser safety policies and procedures are developed, implemented and maintained. The American National Standards Institute (ANSI) Standards Z136.1 "Safe Use of Lasers" and Z136.3 "Safe Use of Lasers in Health Care Facilities" also have requirements for LSOs and LSCs. The OSH Answers document Lasers - Health Care Facilities has additional information on laser safety programs, LSOs and LSCs.

What types of personal protection should workers wear?

Medical personnel should wear appropriate respirators, eye protection, and gloves during laser surgery and when employing electrosurgical units.

Respirators should be used to provide additional protection and not as a substitute for an air exhaust system. Surgical masks do not eliminate the risk of infection or other hazards from inhaling viruses, germs, chemical vapours, tiny dust particles, aerosols, or cellular debris in laser plumes. If engineering controls do not provide sufficient protection then a properly fitting respirator suitable for the contaminants staff are exposed to should be used as protection against airborne contaminants. OSH Answers has more information about selecting and caring for respirators and about other aspects of setting up a complete personal protective equipment (PPE) program.

Document last updated on June 4, 2009

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