Laser-Generated Airborne Contaminants

There is growing concern about laser-generated airborne contaminants (LGAC) that may occur when lasers impact a surface and change or vaporize the material on the surface. The occupational safety literature reports production of nanoparticles from laser interactions. The term "nanoparticle" generally refers to particles <100 nanometers in size.

The type of contaminant varies, depending upon factors, such as:

• The target material
• Cover gas
• Beam irradiance

The target material may be responsible for releasing chemicals that are carcinogenic, toxic, or noxious. These contaminants can include harmful substances, such as:

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

At certain concentrations, LGAC may cause problems, such as:

• Ocular and upper respiratory tract irritation
• Unpleasant odors
• Visual problems for the user
• Mutagenic and carcinogenic properties

The potentially hazardous area for LGAC may often exceed the NHZ.

Ultraviolet radiation from laser discharge tubes, pumping lamps, and laser welding plasmas must be shielded to reduce exposure to levels outlined by ANSI Z 136.1, OSHA permissible exposure limits PELs, and the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit values (TLVs).

Radiation, other than laser radiation, associated with the operation of a laser or laser system, such as radio frequency (RF) energy associated with some plasma tubes, and X-ray emission associated with the high voltage power supplies used with excimer lasers, must be maintained below the applicable protection guides.

ANSI C95.1 outlines the appropriate protection guide for RF and microwave energy. The appropriate protection guides for exposure to X-ray emission is found in OSHA 29 CFR Part 1910.1096 and in applicable State Codes.

Lasers and laser systems, which by design would be expected to generate appreciable levels of collateral radiation, should be monitored.

To learn more about Laser Safety visit our Laser Safety Online Training web page.