Entryway Control Measures for Class 4 Lasers

Specific controls are required at the entryway to a Class 4 laser-controlled area. The controls are summarized as follows:

• All personnel entering a Class 4 area must be adequately trained and provided proper laser protective eye wear.
• All personnel must follow all applicable administrative and procedural controls.
• All Class 4 area and entryway controls must allow rapid entrance and exit under all conditions.
• The controlled area must have a clearly marked "Panic Button," a non-lockable disconnect switch that allows rapid deactivation of the laser.

The ANSI Z 136 Standard provides four options that allow the LSO to provide an entryway control suited for the installation, as follows:

• Nondefeatable Entryway Controls
• Defeatable Entryway Controls
• Procedural Entryway Controls
• Temporary Laser-Controlled Area

Nondefeatable Entryway Controls

Such as a magnetic switch built into the entryway door, which cuts the beam off when the door is opened.

Defeatable Entryway Controls

May be used at an entryway; for example, during long-term testing in a laser area. In this case, the controls may be temporarily made inactive if it is clear that there is no hazard at the point of entry.

Procedural Entryway Controls

Such as a screen that can block or filter the laser beam at the entryway may be used inside the controlled area to prevent the laser light from exiting the area at levels above the applicable MPE level. In this case, a warning light or sound is required outside the entryway that operates when the laser is energized and operating.

If overriding interlocks are necessary during periods of special training, service, or maintenance, and access to Class 3B or Class 4 lasers is required, a temporary laser-controlled area must be created following specific procedures approved by the LSO. These procedures must outline all safety requirements necessary during such operation. Such temporary laser-controlled areas, which by nature will not have the built-in protective features as defined for a laser-controlled area, must still provide all the safety requirements for all personnel, both within and without the temporary laser-controlled area during periods of operation when the interlocks are defeated.

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