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405nm = near UV = can kill germs and virus?

SOG

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I have been wondering... um.... so 405nm is shorter in wavelength and it's near UV, so does that mean it can kill more germs and virus when compare to other wavelength of the same power?

If it can... do you guys know how much wm in power it takes to kill some germs? I tested the 600mw, I found it's quite strong when compare to some UV lights... I got one of those glasses that will react to UV light when it's under the sun.... that glasses's lens turn dark in like 2 sec... while it take about 10 seconds or so under strong sun light.

If it can even kill germs and virus... I/we have another reasons to tell our wives/girlfriend why we need the laser ... "Hey look, I bought this thing because we can uses it to kill the germs off toilet, sink, floor, kitchen knives, cutting boards... :D

Um... I think UV can also de-oder too... (or at least the sunlight can) I wonder if 405nm can do that or not.

Anyone have any ideas :D
 



joeyss

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405 is still incable of killing anything , but your eyes when it's in laser form. You'd need under 350nm of UV for it to start disinfecting.
 

SOG

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Thanks, I see... um... I thought all UV can kill germs and viruses...
Is there other shorter wavelength lasers? :D I think the shortest I have heard is 604, at least that is what is common...
 

honeyx

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405 is still incable of killing anything , but your eyes when it's in laser form. You'd need under 350nm of UV for it to start disinfecting.
I guess there are members who will disagree with you. Some of our members killed anses and other insects with their green lasers. So if you are able to kill bugs with other wavelengths the more you will be able to kill viruses. It´s not necessary the wavelength but the amount of power and so the generated heat that will kill all kind of life.

Btw. Heat is also just a far IR wavelength. With enough power even microwaves will kill viruses. It´s just that UV photons do have a higher energy level than longer wavelengths, so less are needed to kill viruses.
 
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Tech_Junkie

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I guess there are members who will disagree with you. Some of our members killed anses and other insects with their green lasers. So if you are able to kill bugs with other wavelengths the more you will be able to kill viruses. It´s not necessary the wavelength but the amount of power and so the generated heat that will kill all kind of life.
You have no idea of what you are talking about. Insects can be seen, and are sparse. Viruses, and other contaminates are on a molecular level. It would take you a month to sweep a room with a laser. Thats why they have UV lamps to do the job. They kill everything with the RIGHT wavelength, and have a large sweep area. D'uh. I think you need to check Google too before you open your mouth.
 
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joeyss

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I guess there are members who will disagree with you. Some of our members killed anses and other insects with their green lasers. So if you are able to kill bugs with other wavelengths the more you will be able to kill viruses. It´s not necessary the wavelength but the amount of power and so the generated heat that will kill all kind of life.

Btw. Heat is also just a far IR wavelength. With enough power even microwaves will kill viruses. It´s just that UV photons do have a higher energy level than longer wavelengths, so less are needed to kill viruses.
405nm MAY be a higher energy WL , but it's still not damainging to our DNA or cells like REAL UV is past a certain NM. It's the ablity to knock DNA and change the chemicals in cells that determines what WLs can kill stuff like bacteria not the power to "burn".
 
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honeyx

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You have no idea of what you are talking about. Insects can be seen, and are sparse. Viruses, and other contaminates are on a molecular level. It would take you a month to sweep a room with a laser. Thats why they have UV lamps to do the job. They kill everything with the RIGHT wavelength, and have a large sweep area. D'uh. I think you need to check Google too before you open your mouth.

Sure. Viruses and other conatminates are on a molecular level. Exactly like the rods and cones in your retina. So you want to tell me you can´t kill them with a colimated IR laserbeam?

Remember. It was not the question how long it takes but if it´s possible to kill germ and viruses with a 405nm laserbeam.

405nm MAY be a higher energy WL , but it's still not damainging to our DNA or cells like REAL UV is past a certain NM.
Did I say something different?

It's the ablity to knock DNA and change the chemicals in cells that determines what WLs can kill stuff like bacteria not the power to "burn".
Yes, but how is DNA knocked and how are chemicals in cells changed? By the energy causing them to vibrate as strong till the connections are breaking or by ionizecing single atoms.

DNA is also just a bunch of molecules and heat is also causing them to vibrate as strong till the connectoins are breaking. So burning something is nothing else than giving enough energy to it so the molecular structure starts to break.

It was also not the question how they are killed. By cracking the DNA or by demaging the outer structure of a virus.

Mark. You are asking why I´m still here. I´m still here because I´m trying to help people who are getting just answers to ask the new age bible called google, but getting no real help. I´m here because I´m not afraid to get a bad reputation. I´m here because I even am willing to swim against the drift if necessary. I´m here because I´m not one of the lemmngs following the others to jump the cliff.

I´m sorry I couldn´t give a more detailed answer before, but was in hurry to go to work.
 

piferal

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To destroy bacteria, viruses and other biological contaminants in the air, liquids (water purification for example), or on surfaces, are used the UV-C.

And in many cases usually is used a wavelength of 253nm, and evidently lamps are used, no laser.

Sorry but I do not think that the 405nm wavelength has an effect for this task :D
 

honeyx

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Under normal curcumstates, where the 405nm light is emmited by a simple lamp it also will have no effect. All depens to the photondensity and it´s photonenergy measured in eV. Those UV-C lamps and so lasers require also special optics made by pure quarz glass, as normal glass will absorb this short wavelength. The point is, even longer wavelengths can "kill" such small structures if the energylevel is high enough. It´s just UV-C light is effective enought so it dosn´t need to be collimated or emmited from a laser to do the task. It´s because it´s photonenergy is in the rage from 4,43−6,2 eV.
 

chipdouglas

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@ sog... in another thread you say "604nm" i hope it is just a typo. is getting way out of the uv range and into the red. if you want more uv than 405nm then you need to go numerically lower. and as said before 350nm is where real uv comes in. 405 is more violet. uv is like ir, in that you cant really see it.

michael.
 

Cyparagon

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Someone here is distorting the question just so he can argue. Usually when one wants to sanitize, the idea is to destroy the microorganisms only,
and not what they inhabit.

Flamethrowers disinfect, but they're not generally used as a disinfectant.
 
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honeyx

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That´s a good point Cyparagon. Light is anyway not the best way to sanitize something. No matter it´s UV-C light or some sort of laser. I myself am using UV-C Lamps for my fishtank. Have to replace them from time to time. Not because the lamps are getting defective but because the UV light is destroying the plastic housing from the insight where they sit. It´s very agressive not just to living organizms. However they have some benefits if it comes to disinfect a whole environment. That´s why the are often used in hospitals. In laboratories they don´t use UV lamps but small flames to disinfect something and for a household disinficant chemicals are the best choice.

When it comes to the question if a laser can disinfect something then my answer is YES, even an IR Laser can do this when fosused to one point for example on a knife blade or a fork. This will destroy the organizms at this point but not the knife or the fork.

When you ask does this make sense, then the answer is NO. The disinfected area will be as small as the top of a needle. But it´s possible.
 

chipdouglas

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also note that the light doesnt actually kill the bacteria. it renders the bacteria incapable of reproducing. thus dying off without multiplying. that is also why uv is used and not other wavelengths.

michael.
 

Tech_Junkie

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A laser has to be focused to a point to burn. It would take you easily 30 minutes to cover just your toothbrush area. And, as been said, you will destroy most things you're trying to disinfect. So no, its not a good idea to use a laser to disinfect.
 




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