In general, if you are using a higher powered laser projector outside of your home, you must get permission from the U.S. Food and Drug Administration. You may also be subject to state regulation, such as needing a permit, a laser operator’s license and/or having to register your laser projector.

FDA Laser Notice 51 requires anyone who is “introducing into commerce” a laser projector that is Class 3B or Class 4 (e.g., above 5 mW output), to have an approved variance from the FDA. Further, they cannot purchase the laser projector before the variance is approved.

The short version of “introduction into commerce” means just about any use, except for use at home with family and friends. For example, a variance is required if there is some type of commercial transaction, such as a person paying to see a concert or have drinks at a bar where a laser projector is being used. It can also mean that an advertiser is paying to support an event with free admission, or the laser is advertising a product, service or event that costs money.

For any questionable “edge cases”, such as whether you can use a laser projector outside your home for a large-scale neighborhood Christmas display, it may be advisable to obtain a variance anyway. This way, if authorities raise any questions, you have documentation that your use is permitted under federal law.

Under U.S. FDA regulations, anyone creating a laser light show is a laser light show manufacturer. This is because you have “manufactured” a show that was not there before. You are also a laser light show manufacturer if you substantially change an existing show, so that it has different safety characteristics or potential hazards.

See the page U.S. Laws for more information on what a manufacturer must submit to FDA.

Under U.S. FDA regulations, normally any laser above 5 mW (very weak, the limit of “legal” laser pointers) would not be allowed to do a laser light show. But you can apply for a “variance”, or permission to vary from FDA regulations.

The text below is taken from FDA Laser Notice 51. Material in brackets and italics [like this] are clarifications and comments by ILDA.

Note that the title of LN51 only seems to include the “manufacturers, dealers and distributors” of laser light show projectors. However, LN51 also applies to anyone purchasing a laser, or a laser projector, who is using it to create a laser light show. In other words, if you buy a laser projector and set it up in a public (“introduction into commerce”) show, you have become a laser light show manufacturer, and you are subject to the provisions of LN51.

Selected text from FDA Laser Notice 51

Issue

…We also know that some manufacturers of laser light show projectors sell equipment to customers without obtaining an approved variance from us, which is not acceptable.

Background

We may grant a variance from the requirements of the Federal Laser Performance Standard for Lasers and for demonstration laser products [including laser light shows]…. The variance, therefore, allows you as the manufacturer of laser light show and projector to deviate from the existing performance standards required by federal regulation.

As you know, all manufacturers of Class IIIb and IV laser light shows and laser light show projectors must have approved variances from us to perform laser light shows and introduce laser light show projectors into U.S. commerce. Prior to performing laser light shows or introducing laser light show projectors into U.S. commerce, the manufacturer must submit the following to us at CDRH:

• A Product Report describing the laser projector
• A Laser Light Show Report describing the laser light show, and
• A variance application requesting permission to deviate from the Federal Laser Performance Standards.

Only the Laser Light Show Report and variance application must be submitted if an individual or firm purchases a certified laser projector for which a Product Report has already been submitted by the projector manufacturer. [If you are buying a pre-made laser projector, you will put the name and model of the laser projector on the variance application. FDA will check to see if there is an existing Product Report for this particular model of laser projector.]

Good questions. The short answer is that the multiple laser beams from this projector are not supposed to go into any area where a person might reasonably be expected to be.

Here are details.

According to the manufacturer’s user manual, the multiple beams (e.g. after being split from the 100 milliwatt red and 30 milliwatt green laser diodes) are each less than 5 milliwatts maximum.

Visible lasers between 1 and 4.95 milliwatts are U.S. FDA Class IIIa (3R). This is the same maximum power as a laser pointer, which in the U.S. must be below 5 mW.

So basically this projector is sending out dozens or hundreds of laser pointer beams.

People can have a brief, accidental exposure to a laser pointer beam but 1) for safety they must not stare into a beam and 2) legally you cannot deliberately aim a laser pointer at them.

The user manual specifically states this. From page 4: “According to laser safety regulations, it is not legal to aim Class 3R lasers into areas where people can be exposed, even if the laser is aimed below people’s faces such as at a dance floor.”

This is true. Under U.S. FDA regulations for laser light shows, any laser beam above 1 mW cannot be lower than 3 m (10 ft) from the floor or other surface on which a person could reasonably be expected to stand.

If your ceiling is below 3 meters, you could not legally use the laser projector. If the ceiling is 3 meters or above, you can legally use the laser projector as long as no beams go below the 3 meter legal limit. To do this, you could use sturdy foamcore, black foil or similar materials to mask off the bottom of the beam “star field”. Just be sure no beams are below the 3 meter limit.

You may have been to other events and shows where lasers went directly into an audience. Sometimes this is done legally, with the laser producer having an "audience-scanning variance" from FDA. Such a variance ensures the laser power in the audience is at a level considered safe (below 2.5 mW per sq. cm.).

All too often, however, audience scanning is done illegally — and probably with no knowledge of the actual beam power which is in the audience area. Such shows are definitely illegal and are probably unsafe for eye exposure.

This question is answered at LaserSafetyFacts.com’s Class 4 laser webpage. Scroll down to the section titled “CLASS 4 SAFE USE GUIDANCE - LASER PROTECTIVE EYEWEAR (GLASSES)”.