Koch Lab:Protocols/Laser Safety

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Intro

Steve has taken approximately 30 hours of laser safety at Argonne National Lab, Cornell, Los Alamos National Lab, and Sandia National Labs. The main point of those training sessions is to describe the pain and blindness that occurs when a powerful laser is accidentally shined into an eyeball. For example, the high power infrared laser (such as the CVI YAG laser) if shined into your pupil will immediately cause your retina to rupture. Even if it's not in your field of view, you're likely to go blind, because the debris will fill up your vitreous humor clouding your vision. It's also probably painful, if not when it happens, when the healing goes on.

In any case, no amount of classroom training can replace the basics of hands-on training and these essential elements:

  • Respect for the danger
  • Respect for others' safety
  • Respect for your own safety
  • Understanding of the need to put respect of safety above all other factors (including a feeling of urgency to get an experiment completed).
  • Carefulness in place of haste

It's that last element that is the doozy, because sometimes being safe is uncomfortable and can slow things down considerably. Steve's job as PI is to encourage and reward safe behavior, even when it means the construction of apparatus is slowed down.

One safety instructor pointed out in a training session that ultimately, these behaviors that promote safety (founded in respect and carefulness) ultimately result in much better science anyway. That is, the safest people are the best scientists and the best colleagues in the long run. The same person who cuts corners on safety is the same person who uses the last of the key reagent and puts the bottle back in the cabinet without ordering more.

General Laser Safety

  • Take the time to be safe.
  • Learn about laser dangers
  • Use a safer laser, if possible. That is, if you don't need invisible laser, use a visible one. If you only need 1 mW and your laser is 100 mW, consider affixing a neutral density filter to the laser to make it generally safer.
  • Spend the money on the required safety materials. An obvious one is laser safety goggles of the correct and comfortable type. Less obvious are things like a camera able to detect IR light, to make wearing safety goggles less annoying.
  • Always think about your eyes, your lab-mates' eyes, and visitors eyes.
  • Consider what happens when other people mess with what you're doing. E.g., what happens if 20 8th graders come into the room? If you're the only one who can reasonably use the laser, keep the key on your keychain.
    • In addition to laziness and a cavalier attitude, the laser accident at Los Alamos is attributable to a lack of imagination about who may be using the laser (i.e. a person shorter than 5' 10" or whatever).
  • Don't wear shiny things below your elbows. Rings, watches, etc. These can specularly reflect laser light into someone's eyes.
  • Try to keep the laser beam parallel to the floor and far below eye level (this is a problem when people are sitting in the room). If you need to increase the height of the path, do it so the beam is vertical. You're avoiding situations where you're aligning a beam that would be at eye level if you miss your target.
  • Isolate laser operations from people not involved in the operation. I.e. with a black curtain, or a special dedicated laser room.
  • Use interlocks to automatically shutoff the laser when rare situations happen. E.g., you can connect the door to a room to a laser interlock.
  • Explain to others who enter the work area why they are safe, and how to stay safe. If it's just a plain safe laser (e.g. 1 mW red laser), don't assume they know that.
  • Enforce safety on others and kick their ass if they won't be safe.

Specific Safety Pages

High power IR lasers

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