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Safety of small China manufactured stage lights

discofever

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Hi all,

I did try to search but could not find a discussion of safety of small Chinese stage lights, like the one in the picture attached.

The device has a printed classification 3b, and automatically creates moving patterns. Of course people use these so that laser beams also hit the eyes occationally, directly or by reflection. In marketing material lasers scan audience etc.

I understand it's impossible to know real power of the lasers, the timing of the patterns etc., but has anybody any idea, how safe / unsafe these are?
Should the device be assembled so (high) that laser beams can't meet the eyes or am I just over concerned?
 

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Encap

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Knowing the real power is very possible--measure it with a laser power meter.

Class 3b is an eye hazard---not legal for sale in USA nor legal for public performance without a US FDA Variance.

"Lasers used for demonstrations, shows, displays and entertainment are highly regulated in the U.S. Both the laser projection device and the way in which it is used (the laser show) must be certified to the Food and Drug Administration. This is for ANY laser show even if the laser beam is kept away from audience areas. Generally, shows in a private home with friends and family are not covered but all other demonstrations, shows, displays, etc. done with a Class 3B or 4 laser would require the user to submit a variance, and get FDA approval in advance before the show can proceed. Do not perform any public demonstration, show, display or entertainment with this laser projector, without having a variance from FDA."
"Scanning the laser beam, by moving it quickly in various patterns such as lines or circles, does NOT significantly reduce hazards.
Do not aim this laser projector directly at any person or audience area. Deliberate scanning onto an audience with a Class 3B or 4 laser is inherently hazardous. "
You can read more about 3b laser hazard in general and also scroll down and see the section on Laser Projectors here: https://www.lasersafetyfacts.com/3B/
 
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discofever

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Thank you for your detailed response.
I know 3b is an eye hazard, but I was thinking that perhaps someone would have some idea of the real power of these devices. The prices are around 30 usd, but lasers are so cheap nowadays, that even that does not tell much. Measuring the laser power would of course be the best option.
 

Encap

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Idea of real power? LOL There are no "these devices" or answer about them.
Every device will vary a bit but the specs say what this particular manufacturer claims the to be.
What do you want a fairy tale answer about a fairy tale group of things called "these devices" ?
The real world is not hypothetical ---broad generalizations are just that and only exist in imagination.
No 2 real things are exactly the same.

The one in the picture you posted is sold in a lot of places including eBay and elsewhere.
The specs are listed in every offer --no reason to doubt them.
Combination of RGB LED and 2 lasers a 30mW green and 100mW red. 5mW to 499mW is class 3b
Too lazy to read the specs?
Are they low end, throw away toy quality---yes they are.
If you want to know the actual output of any example of a laser or device incorporating a laser, you need to measure it with an LPM/laser power meter

See: https://www.ebay.com/itm/60-Pattern...660929?hash=item2f33459481:g:jQAAAOSwctddGsxa
 

discofever

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Ok, fair enough. Of course I read all the details (and about classifications), but as you know Chinese tech specs, they can be true or not, that's why I asked if someone happened to know more. Also, a device looking the same and even from same vendor can differ in real specs, that I know too.
Thanks anyway, it seems being careful was the right choice, so I assume the power is enough to be dangerous.
 

Hap

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Thanks anyway, it seems being careful was the right choice, so I assume the power is enough to be dangerous.
Yes. If you don’t know the particular power of a laser always assume it’s powerful enough to cause harm.

-Alex
 

Encap

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Ok, fair enough. Of course I read all the details (and about classifications), but as you know Chinese tech specs, they can be true or not, that's why I asked if someone happened to know more. Also, a device looking the same and even from same vendor can differ in real specs, that I know too.
Thanks anyway, it seems being careful was the right choice, so I assume the power is enough to be dangerous.
Careful is always the best choice--assumed it can cause harm as Hap mentioned and as mentioned in post #2 and detailed here: https://www.lasersafetyfacts.com/3B/

If the manufacturers say 3b and it is $20 or there abouts, there is no chance that it is Class 4 due to cost and complexity or less powerful than 3b and legal to import, sell and use in USA or it would be marketed as same.

Asking the seller to verify the actual mW output of the product he is offering and if over 5mW has the device been granted an US FDA Variance makes much more sense.
 
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paul1598419

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These cheap projectors often use only red and green lasers and run them through a pair of rotating diffraction gratings. Often the red laser is the most powerful as it has the least visibility when compared to the green laser. After they are diffracted, they are less powerful as the beams are spread everywhere. Exactly how much less powerful is the question.
 




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