SAFETY ALERT for laser users

 

The UW was recently notified of a potential hazard for users of laser equipped microscopy equipment manufactured by ZEISS. The hazard identified by the manufacturer is potential exposure to Class IIIb laser light, which can cause serious and permanent visual impairment. All users of laser equipped microscopy equipment should contact EH&S immediately if using or possessing the following equipment:

  • ZEISS laser equipped microscopy equipment and laser equipped imaging systems, including 
    • Cell Observer SD
    • Direct FRAP
    • Laser Scanning Microscopes 
    • Laser TIRF Imaging Systems 
    • Elyra Systems
    • Lightsheet Systems
  • Model numbers LSM 510, LSM 710/780/880 UV and NLO

Faculty and staff in possession of equipment listed above should take necessary steps to eliminate the risk of injury, including determining whether there is potential exposure to Class IIIb laser light. Please see detailed instructions below.

EXPLANATION OF THE ISSUE AND INSTRUCTIONS FOR DETERMINING POTENTIAL RISK

The issue (as defined by the manufacturer)
The shutter may not be completely closed, although the system thinks it is “laser-safe,” it is possible or laser light to be reflected from a dichroic in the reflector turret into the eyepieces, or onto the sample. This can be a particular concern with TIRF systems, as the laser may leave the objective in a very flat, unexpected able. As a result, in certain configurations and conditions (detailed below), there is the potential for exposure to Class IIIb laser light, which can cause serious and permanent visual impairment.

Determining potential risk (per instructions from the manufacturer)
Use the following steps to verify, and if verified, minimize the risk of injury.

1) Potential risk: Looking into the eyepiece (where applicable) when the laser is switched on.
a) Is light getting through the shutter?
i) Close the laser shutter.
ii) Switch off all other light sources.
iii) Can you see light on the sample? 

  • If Yes, go to “c” below.
  • If no, continue to “b.”

b) Is light leaving the binocular tube?
i) Remove the eyepiece.
ii) Put a piece of paper in front of it.
iii) Can you see light on the paper? 

  • If yes, go to “c” below.
  • If no, your system is currently safe.

c) If you see light in either test, to mitigate the risk, use the camera rather than the eyepieces to observe your sample when the laser is switched on.

2) Potential risk: Tilting back the transmitted light arm (where applicable) when the laser is switched on.
a) With the laser turned on, before working on the sample, place a piece of paper over the transmitted light arm when it is tilted back. 

  • If you see no light, your system is currently safe.

b) If you see light in the test, do the following to mitigate risk:

  • iDon’t tilt back the transmitted light arm when the laser is switched on.
  • If you need to tilt back the transmitted light arm, cover the objective or the sample.

Remember: Never look into the laser beam.

Please contact Amy Lim, laser safety officer (amylhlim@uw.edu or 206.685.5311), if you identify equipment with a potential defect.