I have this 18w /52 lamp from philips: https://www.lighting-gallery.net/gallery/displayimage.php?pos=-244893


I checked its spec sheet and it says that it mostly emits in the 400-500nm range with a peak at 450nm, and it's main purpose is for jaundice treatment. It also doesn't emit any shortwave UV-B.


Can I use it for general blue lighting?

Read here: https://en.wikipedia.org/wiki/Biological_effects_of_high-energy_visible_light

A sane reference I prefer to use when assessing dangers of different light sources, particulary UVA, violet and blue is to compare skin exposure to the exposure caused by sunlight in that band. Sun exposure data is easy to find by googling, there are multiple measurements already made.

I bet blue lamp skin exposure at a reasonable distance is at least a couple of orders lower than the one you get on a sunny day.

One particular danger of high power blue LEDs is a huge point brightness, which in theory can cause almost laser-like damage on the retina, but fluorescent lamp is diffuse, so certainly does not have this problem at all...

Not for eyes

The eye changes the pupil size based on the overall light present (of the entire visible spectrum). So a light source containing only or mostly the narrow band blue light, will expose the retina to more blue light than the blue light present in a white light source, even if the power levels are different by an order of magnitude

There are multiple mechanisms of damage caused by blue light. Some relate to fast damage by high intensity point sources, and some relate to very slow (years) damege by any lighgting (including reflected light) which spectral content of blue exceeds what is normal for the eye

In the case of the FL tube :

 - The mechanism of fast damage is prevented by the light from the tube being diffused

 - The mechanism of slow damage can be prevented if the exposure to the light is not for extended periods (like the permanent lighting installed somewhere), or if the place is illuminated by more lamps of different colors and the blue is not too significant part of the overall lighting

But... Get a life... We are talking about a weak (a few watts) diffuse source of blue light used within a reasonable distance for a reasonable time. Eye is still pretty much sensitive to blue light in this range, and pupil reflex still pretty much works, that's not UVA!

Yep I am aware of all that BS and hype around 'dangerous' blue light from CFLs, now LEDs and charlatans that milk innocent audience by selling utilities that turn mobiles screen yellow, and yellow glasses, OK. But name any honest, *peer reviewed*, *blind tested*, *evidence based* science on this? And note again, natural sunlight, and even more, overcast light is pretty much blue dominant @10000K color temp at magnitudes higher illuminance level! 

 

We don't know if the OP's time is reasonable. Maybe he wants to light his room with it while watching TV 3 hours every day ?

There are multiple damage mechanisms related to blue light

The mechanisms with quickly propagating effects are easy to investigate, they were scientifically tested and peer reviewed ad nauseum, light sources classified to risk groups, standards written, and everyone is happy

The mechanisms with slowly propagating effects are very hard to investigate, because the exposure to excess blue light in normal conditions is not extreme, and over long periods (years) people have more different things that affect their health, than just the blue light content in LED lighting. It is hard to gather evidence, and even with a positive result, nearly impossible to trace it back to blue light exposure from general lighting (and not for example, increased screen time on the phone, stress, ecology, etc). Occasionally some research that shows a risk is present shows up, and is cancelled by everyone who doesn't like the result

The general claim i see (and yours is no different) is that the EN 62471 classification of light sources to risk groups, or more generally the *peer reviewed*, *blind tested*, *evidence based* research results, apply to all damage mechanisms. This is simply not correct, they apply only to the damage mechanisms that were researched in those researches

Well, I only need it for 4-5hrs for a party.

I've an Aliexpress 20000K 70W MH lamp that have a similar blue color.

@Ash

Well, a life at any temperature above 0K sure does some damage over time

I dare to say this lamp is 100% harmless in any use, be it a party, watching three hours of TV or even sleeping all night hugging its warm body. Just insulate the sockets really well in the later case

To put things in perspective. This lamp radiates around 5W of blue light about omnidirectionally. So at any reasonable distance one can expect an energy flow of well below 1W/m^2, right? At the same time, natural sunlight is around 1.5kW / m^2 at noon, not all of this is blue, but some 100-200W sure is.

Of course almost all of the earth species, and mammals, and us humans as mammal species are evolved over millions of years to tolerate this 1.5kW/m^2 sunlight irradiance really well. And even employ blue light for something useful like color vision or bilirubin breakage)

Do you see any warnings in this lamp etch or datasheet? And corporate lawyers are really paranoid

Answer for LAB27 : There is no risk in a 5 hour party, or even much more than that.



Assuming we don't stare directly at the sun or at the lamp, we compare light reflected from surfaces. The incident light on the surfaces in the blue band (your data) is 200 W/m^2 vs 1 W/m^2

Under full daylight sun the size of the eye pupil will be at its smallest. In a room illuminated just by the light of the lamp, it may be fairly large. The coefficient by which the eye pupil can enlarge or shrink is about 5x (max) in the pupil diameter, so 25x in the pupil area. The pupil can compensate for the difference in power by a factor on he order of 25x

This means the ratio of exposure of the retina to blue light from sun vs lamp, is not 200 to 1, but may be as low as as 8 to 1 (worst case)

Then consider also the color of the surfaces that the light is reflected from :
 - Sun light is commonly viewed outdoors. Many surfaces in the field of view have relatively low reflection coefficient for most colors : Green plants, darker color plant stems, soil, materials of paved ground surfaces, etc
 - Lamp light is commonly viewed indoors. Many surfaces in the field of view have very high reflection coefficient for all colors : White walls, white surfaces in areas of activity (paper, dining table, etc)

The difference in reflectivity of surfaces can easily exceed the 8x. So we may actually be fairly close to 1:1, or in the worst case even exceed it