In addition to potential to biological hazards (eye and skin)
Class 4 lasers present a potential fire hazard The problem is
that entertainment laser effects are so beautiful that we often
forget there are hazards associated with them.
Fun Fact: Do not look into the laser beam with your remaining
eye!!! Check out this video: Dumb Ways to Blind Yourself on
You Tube: https://www.youtube.com/watch?v=n6ejwtuOf-0
This really is no joke! While the eye is the most regenerative
organ in the human body by directly viewing a laser beam the
lens of your eye becomes a magnifying glass – with an optical
gain of 100,000! The result is that laser light will cause a per-
manent burn spot (scotoma) by exploding the rods and cones
lining the retina. One can actually hear them ‘pop’ – which
sound like a volcano in your head! Know that you cannot blink
fast enough (called the human aversion response) to protect
yourself from a Class 4 exposure.
Ok so this is an extreme example – technicians who are work-
ing on a laser projector with the protective cover off are the
most likely to incur this sort of injury. There are very simple
basic steps (procedures) a trained operator must follow to
prevent the risks associated with lasers. Read on for more in-
formation on laser safety but first….
you is expired? Ask to see the laser show company’s acknowl-
edgement receipt from FDA for their most recent annual re-
port. In 2007 the FDA issued Laser Notice 55 permitting auto-
matic renewal of certain laser light show variances if required
annual reporting requirements are met.
Venues: Indoor or Outdoor, terminated or
unterminated?
Professional laser show companies will need to know about
your venue. Is the venue indoors or outdoors? If outdoors it
is always best if lasers can be terminated rather than shoot-
ing into airspace. The reason is that laser light may be bright
enough to cause distraction, glare, or temporary flash blind-
ness to pilots; especially during critical flight phases such as
landing and takeoff.
Fun Fact: As of June 2016, the FAA no longer requires laser
companies to notify for terminated outdoor laser activity. But
what exactly qualifies as ‘terminated’?
How about that building across the street behind your audi-
ence or how about those trees? Does that building have win-
dows? If so will there be anyone who has access to that build-
ing during the laser part of your event? And those
trees – even if they are abundant such as a thick
forest of fir trees they are not generally considered
an adequate termination surface. And about that
building 3 to 4 blocks away with no windows – is
it possible a helicopter might drop down into the
beam path?
That is not to say you cannot have outdoor unter-
minated lasers! It just means the laser show compa-
ny is legally obliged to notify the FAA of proposed
activity. The FAA will conduct an aeronautical study
and determine if they object or not.
What do you need to know if you are considering hiring a
laser company?
First and foremost, for shows in the USA ask to see the laser
show company’s variance. A variance is formal permission
from the Food and Drug Administration (FDA) to deviate from
a requirement of the regulations. Think of a variance as a li-
cense issued by the Federal government that ‘allows’ Class 3B
and Class 4 lasers to be operated before the general public
for entertainment purposes. Because the beam path of these
lasers is not ‘enclosed’ there are potential risks to public safe-
ty. Therefore, if you are hiring a laser show company it is im-
perative that you ask to see their variance. The FDA can hold
event promoters accountable for hiring non-varianced laser
companies.
Fun Fact: What if the variance a laser show company shows
If your venue is indoors then you have nothing to
be concerned about, right? That depends on what
sort of reflective surfaces exist and where they are
located. Old theaters tend to have crystal chande-
liers and/or mirror ceiling tiles. Class 3B and Class 4 laser re-
flections can be just as dangerous as when viewed directly!!!
There are 2 types of reflection a laser operator needs to be
aware of – specular and diffuse. Specular is mirror like, diffuse
is ‘fuzzy’ such as laser light reflected off crumbled ‘brushed’
side of aluminum foil. We will discuss what control measures
a laser operator will consider to avoid unwanted reflections
in a bit.
Fun Fact: It is always better to have more powerful lasers,
right?
Wrong – Not only can the higher the power lasers offer great-
er the risk but they have limited artistic appeal. Just because
one company can offer ‘high powered’ lasers does not mean
you will get a better show. For most theaters 3-5W lasers are
adequate. More lasers rather than more powerful lasers will
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