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Page last updated
JMarch 1, 2005

User Advisory

Overview

This advisory is designed to give ALS users who intend to use Class 3b or Class 4 lasers at the ALS an overview of the requirements of the ALS/Berkeley Lab laser safety program. It does not replace official ALS and Berkeley Lab policies and procedures concerning laser safety. For more information on these policies, refer to Chapter 16 of the Laboratory's Health and Safety Manual, PUB 3000.

The primary objective of the ALS/Berkeley Lab laser safety program is to ensure that no laser radiation in excess of the maximum permissible exposure limit reaches the human eye or skin. Additionally, the program is designed to ensure that adequate protection against collateral hazards is provided. These collateral hazards include the risk of electrical shock, fire hazards from a beam or from use of dyes and solvents, and chemical exposures from use of chemicals and vaporization of targets.

Policy

The Berkeley Lab policy on laser safety requires that all lasers and laser systems be operated in accordance with the American National Standards Institute (ANSI) Z136.1, Standard for the Safe Use of Lasers, as well as other applicable regulations. These requirements for laser safety are complex and include engineering controls, administrative controls, medical surveillance, and training. To implement the policy properly while giving the greatest possible latitude to the researcher, all laser operations at the ALS must be reviewed and approved by the Berkeley Lab Laser Safety Officer (LSO).

Safety Plan/Activity Hazard Document

All Class 3b or Class 4 laser operation must be covered by an approved Activity Hazard Document (AHD) before the lasers can be used. The ALS Division Safety Coodinator (ext. 7407) will assist experimenters in developing this plan. Copies of the approved AHD must be posted by the beamline.

Laser Safety Training

All ALS users of Class 3b and Class 4 laser systems are required to take the Berkeley Lab Laser Safety course, EH&S-280, and it is recommended that non-laser-users in the research group also take the class. This presentation is offered monthly; contact ext. 2228 or see the EH&S trainingWeb site for the schedule. A computer-based version of this class is also available at the User's Service Reception area on the ALS mezzanine.

In cases where ALS users have not had time to attend the laser safety class before their experiment begins, the ALS requires that at least one Laboratory-trained laser user be present whenever a Class 3b or Class 4 laser is in use. It is the responsibility of the trained person to act as the Laser Safety Supervisor for that shift and be in visible line of sight at all times when exposure to laser radiation is possible.

Eye Examination

All laser users who will be at the Laboratory for more than one consecutive month must receive a special Berkeley Lab baseline laser eye examination, although the ALS encourages all laser users to have one regardless of their length of stay. The eye exam can be performed by an optometrist through the Berkeley Lab Health Services Department (ext. 6266) or by the user's personal doctor. If a non-Laboratory doctor performs the examination, a Berkeley Lab examination form must be completed; please contact the ALS User Services Office for a copy of this form.

Additional laser eye examinations may be required whenever any laser eye exposure is suspected.

Review of Laser Setup

The Berkeley Lab Laser Safety Officer or designee must review every ALS laser setup on the ALS experiment floor prior to its initial use, or whenever the setup is modified.

Beam Hazard Controls for Lasers Operating at the ALS

In order to avoid inadvertent exposure to laser radiation, the following safety measures are required for class 3b and 4 lasers operating at the ALS:

1. All lasers must have an illuminated laser warning sign that is interlocked to the laser. The sign must be approved by the Laser Safety Officer.
2. Two physical barriers must enclose the laser and the area in which it is operating. The first barrier, designed to contain the beam, can be a plastic casing or beam tube around the laser. The second physical barrier, a hutch or approved laser curtain, must have a standard door interlocked to the laser in order to prevent unauthorized access to the area.
3. The location of the laser emergency cutoff must be posted on the access door to the hutch or laser curtain.
4. All  users of Class 3B and Class 4 lasers must comply with Berkeley Lab’s protective eyewear policy as stated in Eye Protection, section 16.8.5 of  the lab’s Health and Safety Manual, PUB 3000:

   “It is LBNL policy that laser protective eyewear must be worn by all persons within the Nominal Hazard Zone (NHZ) whenever there is an open Class 3B or Class 4 beam.  The NHZ is usually considered to be the entire room or lab in which the laser is located.”
   

For experimental setups where the laser beam can be enclosed within the first physical barrier and where the potential for exposure to laser radiation above permissible limits does not exist, alternate controls to preclude the entry of unprotected personnel while laser radiation is present in the control area may be used. The LSO and ALS management shall review and approve alternate access controls.

More Information

For questions concerning Berkeley Lab laser safety requirements and procedures, contact the Berkeley Lab Laser Safety Officer (ext. 5256).