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University of Pennsylvania Laser Safety Manual

Table 1. Control Measures for the Four Laser Classes

This summary is taken from the ANSI Z.136.1-1993. Refernce numbers in the parentheses refer to sections in the standard.

Control Measures Classification
Engineering Controls 1 2a 2 3a 3b 4
Protective Housing(4.3.1) X X X X X X
Without Protective Housing(4.3.1.1) LSO Shall establish Alternate Controls
Interlocks on Protective Housing(4.3.2) % % % % X X
Service Access Panel(4.3.3) % % % % X X
Key Control(4.3.4) -- -- -- -- * X
Viewing Portals(4.3.5.1) -- -- MPE MPE MPE MPE
Collecting Optics(4.3.5.2) MPE -- MPE MPE MPE MPE
Totally Open Beam Path(4.3.6.1) -- -- -- -- X,NHZ X,NHZ
Limited Open Beam Path(4.3.6.2) -- -- -- -- X,NHZ X,NHZ
Enclosed Beam Path(4.3.6.3) None is required if 4.3.1 and 4.3.2 are fulfilled
Remote Interlock Connector(4.3.7) -- -- -- -- * X
Beam Stop or Attenuator(4.3.8) -- -- -- -- * X
Activation Warning Systems(4.3.9) -- -- -- -- * X
Emission Delay(4.3.9) -- -- -- -- -- X
Indoor Laser Controlled Area(4.3.10) -- -- -- -- X,NHZ X,NHZ
Class 3b Laser Controlled Area(4.3.10.1) -- -- -- -- X --
Class 4 Laser Controlled Area(4.3.10.2) -- -- -- -- -- X
Laser Outdoor Controls(4.3.11.1) -- -- -- -- X,NHZ X,NHZ
Laser in Navigable Airspace(4.3.11.2) -- -- -- * * *
Temporary Laser Controlled Area(4.3.12) %,MPE %,MPE %,MPE %,MPE -- --
Remote Firing & Monitoring(4.3.13) -- -- -- -- -- --
Labels(4.3.14 and 4.7) X X X X X X
Area Posting(4.3.15) -- -- -- * X,NHZ X,NHZ
Administrative & Procedure Controls  
Standard Operating Procedures(4.4.1) -- -- -- -- * X
Output Emission Limitations(4.4.2) -- -- -- LSO Determination
Education and Training(4.4.3) -- -- * * X X
Authorized Personnel(4.4.4) -- -- -- -- X X
Alignment Procedures(4.4.5) -- -- X X X X
Protective Equipment(4.4.6) -- -- -- -- * X
Spectator(4.4.7) -- -- -- -- * X
Service Personnel(4.4.8) %,MPE %,MPE %,MPE %,MPE X X
Demonstation with General Public(4.5.1) MPE,+ -- X X X X
Laser Optical Fiber Systems(4.5.2) MPE MPE MPE MPE X X
Laser Robotic Installations(4.5.3) -- -- -- -- X,NHZ X,NHZ
Eye Protection(4.6.2) -- -- -- -- *,MPE X,MPE
Protective Windows(4.6.3) -- -- -- -- X,NHZ X,NHZ
Protective Barriers and Curtains(4.6.4) -- -- -- -- * *
Skin Protection(4.6.5) -- -- -- -- X,MPE X,MPE
Other Protective Equipment(4.6.5) Use may be required
Warning Signs and Labels(4.7) -- -- * * X,NHZ X,NHZ
Service and Repairs(4.8) LSO Determination
Modification of Laser Systems LSO Determination
Legend
X Shall
* Should
-- No requirements
% Shall if enclosed Class 3b or Class 4
MPE Shall if MPE is exceeded
NHZ Nominal Hazard Zone analysis required
+ Applicable only to UV and IR lasers
LSO Laser Safety Officer (EHRS)

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