What is it about coil lights?

[counting]

What is it about coil uvb that makes it unsuitable and damaging to tort eyes?
Yesterday we made a little trip and visited the world oldest gopher tortoise. His lighting set up uses a heat lamp and a uvb coil pointed at his basking area.
This got me thinking. What is it that's so damaging? Obviously he hasn't really suffered ill...is it brand, species or tort specific which animals are more sensitive.

Anyone want to explain to me?. I have read they are damaging and wouldn't likely personally take the risk.

 

[Yvonne G]

In the beginning, the harsh rays were concentrated out the end of the bulb. They have since fixed it so the rays are now spread out evenly, however, there was never a recall, so the original bad bulbs are still being sold and are still in circulation. Since we have no way of knowing good from bad, we color all of them with the same pencil - all bad.

It didn't seem to affect older tortoises, just babies.

 

[wellington]

Ditto what Yvonne said. I also think the problem is they are meant to hang going left to right not up and down, but most reptile fixtures hang the bulbs up and down.
It's just not worth the risk. A lot of people will buy them cuz they are cheaper. Well, you get what you pay for. Cheap most of the time in this case gets you a tortoise with swollen closed sore eyes.

 

[counting]

Thanks guys! I won't be using them I just wondered after seeing one in use. It makes sense though since he's near 100 years old and not a baby, and is probably using the corrected type of coil bulb that he doesn't have problems with it. It is hung up and down not side to side.

I also can't believe there wasn't a recall! What a joke..and tbh probably will cost more money from them in the long run when people continue to refuse to trust their product.

 

[Markw84]

OK. This has been bothering me all night, and I can't let it sit. To me we are giving out too much mis-information from the confusion on this. I personally believe it takes away from the credibility of this forum.

Compact fluorescents were created to provide a smaller, compact source of UVB in situations with limited space. They can produce good, high levels of UVB but in a small effective area. They are designed to be installed in absolutely ANY direction. Vertical, horizontal, angled, ANY WAY you want. The structure and shape is designed to emit "light" equally in all directions. That is one of it's main purposes. Confusion must come from the recommendation that ALL UVB sources be mounted so the UVB is coming from above the reptile. Therefore, with long tube fluorescents, the recommendation is that it must ONLY be mounted horizontally. Compacts are designed to be hung in any manner.

When these bulbs were first being created, the technology for producing good UVB was in the experimentation mode. As we know, glass filters UVB. So what do you do with the outer tube (glass) of a bulb? Also, fluorescents work by vaporizing a small amount of mercury, which then emits "light". Same as a mercury vapor bulb. But fluorescents use a gas that fills the tube that "fluoresces" and a phosphor coating to the inside of the tube that filters and controls the wavelengths of light actually passing out of the tube. So you have a manufacturing process that must get the type of "glass" the tube is made of AND the proper phosphor coating correct to emit the exact wavelength of light you are trying to produce. Good UVB lights are expensive as they cannot use regular glass and must use another crystal that will not block the shorter wavelengths of UV. To produce a good UV source, you have to find combinations that will allow wavelengths of light in UVA and UVB range, but still block wavelengths in the harmful Short UVB and UVC range. AND the UVB range needed for D3 synthesis is a very narrow range of wavelength that is very close to the shortest UVB and harmful UVC wavelengths. The challenge is to produce UVB in the 295-300nm range for D3 which is very close to the 290nm which is the upper limit of damaging UVC. So different combinations of crystal and phosphors were being used and offered as solutions.

THE PROBLEM

Some of these earlier bulbs ended up emitting light under 295nm range. Trying not to get technical but that means the very shortest UVB lengths and actual UVC. Additionally, with the ability to place a smaller bulb in much more locations in the enclosure, and in smaller enclosures, many keepers, especially with basking lizards, placed bulbs where the reptile could get way too close to the bulb (Near a branch). UVB in the proper range to synthesize D3 is damaging if too strong. So we started seeing cases of eye problems in our reptiles. Now this was with ALL types of bulbs, not just compact. Most, indeed, seemed to be improper placement, which confused the solutions. But some were found to be emitting sub-295nm light. Again, not just compacts, but long fluorescent tubes as well. Since the smaller, more versatile locations of the compact allowed for far more applications where the bulb was indeed too close, we saw more cases associated with those. Even good proper emitting bulbs creating problems, and within the problem, bulbs that emitted too short a wavelength. So the "actual problem" was masked by the extremely easy ability to improperly install the bulb in an enclosure. So the majority of the campaign was and still is designed to solve the issue by trying to provide a much warning as possible about proper placement. Distance charts on packaging, warnings about horizontal long tubes, etc.

Manufacturers were modifying and improving their phosphor recipes, and probably by 2008-2009 no new bulbs emitting sub 295nm light were being produced with the newer combinations. However, many of those older style bulbs were on store shelves in stores and pet shops who infrequently order new stock, and often do nothing to rotate stock on shelves to keep older stock from remaining an incredibly long time in many situations. Add to this the proliferation of online ordering where online sellers of anything, buy older, cheaper stock of many products and dump them to the public who is shopping online for the best deals, totally unaware of who they are buying from or the original source of the product. This can include smaller pet shops looking to stock their shelves. So way past 2009 we still saw actual bulbs that emitted sub 295nm light. But this was the case far too infrequently and actual bulbs produced that indeed were shown to emit sub 295nm light were extremely rare and hard to find. However eye issues are extremely common, and it was way too easy to simply say "its the bulb" just as most do here in the forum, when indeed over half the time a compact fluorescent is not even being used. That's how easy it is to create an overblown perception. And that is what was so hard in convincing manufacturers of the issue of some bad bulbs as most cases turned out to be proven as application, not equipment, and far more "eye problems" were shown to be injury or diet.

What really compounds the issue, is if you were one to experience the actual issues created by a truly bad bulb, it is an extremely emotional and horrendous experience. Those experiences are not forgotten and indeed repeated over and over. So with so much confusion, isn't it much easier to simply say - don't use anything like it, ever?

I will say that I personally use compact fluorescent without hesitation where the situation calls for a small baking area such as my aquatic hatchlings. I contribute to and watch other forums on chelonians, and the others forum never post a concern about compacts, and indeed it is by far the most common type of UVB source used. Since proper lighting is a particular passion of mine, I follow it closely. Since becoming active on this forum and getting into this discussion 18 months ago, I was simply told, "just watch the forum and you will see all the examples you want every month." Well, I have religiously watched for any thread about "eye problems" and follow them. I have not seen one case in those 18 months. I do see several times a day people warning "those bulbs are know to cause eye problems". Yet time after time a real issue with the eye problem is totally unaddressed, especially if any mention of a compact by a poster is included. So THE IMPRESSION of an ongoing problem is extremely present because it is immediately brought up several times every day. So we all have the impression of hundreds of issues "all the time" when in fact, there has been NONE in the past 18 months I have been carefully watching.

When it gets to the point to where we are so myopic that we ignore and cannot see the real possible issues, we are doing a disservice to our forum members and those coming here looking for help. I recall the poster who was concerned about his leopard tortoises eyes, cloudy and closed. Just a month ago or so changed from a compact to a MVB and wanted help. When I saw the thread, some frequent contributors here had replied and echoed concern about that coil bulb, and how the tortoise would probably be OK now. Sooth the eyes, etc. Only one person replied suggesting the bulb might be too close. I was alarmed! I asked when he got the MVB and how he had it mounted. He replied he got it about a week ago and had put it down to 9" above substrate to bump up basking heat. It seemed the tortoise now started the eye problems. 100 watt MVB at 9"!!!!

With tortoises, I believe compacts a poor choice because of their small effective area. They put out great UVB, but a tortoise would need a broader basking area of proper UV index than they create. But I dislike MVB even more as they also have a narrower band of desired UV index under a small bulb profile, but they generate a tremendous amount of near-IR which is tremendously dessicating. Since they can be easily mounted too close for the amount of UVB generated, they can also be potentially damaging far more than compacts to tortoise eyes. Yet how many times will you see that mentioned on this forum? Tube fluorescents are my choice but now with the T5 HO tubes, they also are potentially eye damaging if attention is not paid to proper placement. And - there were tube fluorescents just as compacts with the same sub-295nm emission problems since they both work the same way. No one seems to mention that. The issue was corrected with newer manufacturing processes, yet the stigma fell on the compacts and seems to remain there to this day, at least on this forum.

 

[Tom]

In the beginning, the harsh rays were concentrated out the end of the bulb. They have since fixed it so the rays are now spread out evenly, however, there was never a recall, so the original bad bulbs are still being sold and are still in circulation. Since we have no way of knowing good from bad, we color all of them with the same pencil - all bad.

It didn't seem to affect older tortoises, just babies.

I don't agree with any of that.

Nothing has changed about the design of the bulbs, since they first hit the market. There was a problem with cracks in the phosphor coating in some of the early bulbs and they supposedly fixed that, but I still see problems with these bulbs to this day.

The problem, as I see it, is that some of these bulbs burn reptile eyes, and some don't. Its not just tortoises. Lizards too. Know how to tell which ones will burn their eyes and which ones won't? Me neither. It seems pretty random and that is part of the issue, for every person who has an animal's eyes injured by one of these bulbs, you can find 10 people who say they use them and its not a problem. Well, its not a problem, until they day they get a bad one, burn their reptiles eyes and realize there is a problem.

This is not a problem from old bulbs that has been fixed. It is a problem that is current and on-going. And the chances of a bulb manufactured 10 years ago being sold today as new, is pretty slim.

 

[Tom]

Anyone want to explain to me?. I have read they are damaging and wouldn't likely personally take the risk.

Do a search for coil bulbs. You can read as many hours of arguing as you like. You'll see every aspect of this discussed at length.

 

[Tom]

And - there were tube fluorescents just as compacts with the same sub-295nm emission problems since they both work the same way. No one seems to mention that. The issue was corrected with newer manufacturing processes, yet the stigma fell on the compacts and seems to remain there to this day, at least on this forum.

My problem is that I've never seen a case of burned eyes with a florescent tube or MVB. Not saying it hasn't happened, but I will say its very un-common. Cases of burned reptile eyes from cfl bulbs, by contrast, are quite common. I've seen several myself over the years, and the reptile vets that I work with have seen many as well.

Hence the advice: Just don't use them. Use something safer, or just use real sunshine.

 

[ZEROPILOT]

Most of us are torn between seemingly very knowledgeable members when it come to lighting and other members convinced that the coil type of bulb has badly damaged their tortoises eyes. And seemingly mounting them in all manner of ways and distances.
I myself, parrot the coiled bulb warning only because it seems that the risk of harm is real. There are other options. Not because of first hand ecperience.
Thanks to everyone that is passionate about this matter.
I don't think this conversation will end anytime soon.

 

[Cowboy_Ken]

Again, not just compacts, but long fluorescent tubes as well.

Well said and laid out my friend. Back when I made the transition from keeping meat eating, hole animal eating reptiles to the vegetarian species such as tortoises, fluorescent bulbs, (tube and coil) were just coming out on the market. I can remember all the concerns people were having with the health of their pets while making this transition so I just kept using, and still keep using, MVB in that they seemed to give me what I needed from the ease of building my own mounting system without the complications of all the potential negatives.
Thanks again for a well thought out post here.

 

[Markw84]

My problem is that I've never seen a case of burned eyes with a florescent tube or MVB. Not saying it hasn't happened, but I will say its very un-common. Cases of burned reptile eyes from cfl bulbs, by contrast, are quite common. I've seen several myself over the years, and the reptile vets that I work with have seen many as well.

Hence the advice: Just don't use them. Use something safer, or just use real sunshine.

I have no problem with the advice "I personally would not risk using compact fluorescents, as I have heard of cases in the past of them causing problems".

I think we undermine our credibility when we very commonly state "They are know to and still do cause problems" "frequently cause problems" "are bad for tortoises" "can only be mounted a certain way"

Nothing has changed about the design of the bulbs, since they first hit the market. There was a problem with cracks in the phosphor coating in some of the early bulbs and they supposedly fixed that, but I still see problems with these bulbs to this day.

This is not a problem from old bulbs that has been fixed. It is a problem that is current and on-going. And the chances of a bulb manufactured 10 years ago being sold today as new, is pretty slim.

There certainly has been a lot changed about the phosphor blends they use and continues to be improvements and change. There were no T5 bulbs 10 yrs ago. Or HO bulbs. The newer coil bulbs produce a much stronger and I get totally different reading from them now than I used to. New improvements and better phosphor control is ongoing. Look at what is going on now with the LED industry and they are working on and developing ways to create LEDs with the correct wavelengths to use.

This is not a problem from old bulbs that has been fixed. It is a problem that is current and on-going. And the chances of a bulb manufactured 10 years ago being sold today as new, is pretty slim.

Maybe that's why we are not seeing cases now. Where are they? There are over 1,000,000 of those bulbs that have been sold. Where are the cases now?

 

[Kapidolo Farms]

And there are other considerations not otherwise addressed here.

Coil bulbs ballast's are cheap throw away crap meant only for the one bulb. Does anyone actually count the hours of use, They do not last all those proclaimed hours based on studies published from consumer groups in Australia. That's how crappy that ballast is.

Fixture ballast's are better made intended for multiple tubes' lives.

A 24 watt coil and a 24 watt T5 HO emit the same amount of light, use the same diameter glass tube, but one is too intense for the area of floor space relative to the other. The tube distributes the light over a larger area, As long as the tube/bulb distance is appropriate for the UV's to help process D3, then the more distributed light is acceptable and less intense. For my applications that is better.

Most glass has iron in it. UV's glass has low or no iron. It's the iron in the glass that stops the UV's.

Compact tubes are not equal from all angles, use a reflector and they're still not all equal based on position.

These are NOT equal from all positions without regard to the different wattage.

Hopefully we will get LEDs that produce the range of spectrum that works and we can all argue about a whole new suite of anecdotal concerns.

 

[Markw84]

And there are other considerations not otherwise addressed here.

Coil bulbs ballast's are cheap throw away crap meant only for the one bulb. Does anyone actually count the hours of use, They do not last all those proclaimed hours based on studies published from consumer groups in Australia. That's how crappy that ballast is.

Fixture ballast's are better made intended for multiple tubes' lives.

A 24 watt coil and a 24 watt T5 HO emit the same amount of light, use the same diameter glass tube, but one is too intense for the area of floor space relative to the other. The tube distributes the light over a larger area, As long as the tube/bulb distance is appropriate for the UV's to help process D3, then the more distributed light is acceptable and less intense. For my applications that is better.

Most glass has iron in it. UV's glass has low or no iron. It's the iron in the glass that stops the UV's.

Compact tubes are not equal from all angles, use a reflector and they're still not all equal based on position.


These are NOT equal from all positions without regard to the different wattage.

Hopefully we will get LEDs that produce the range of spectrum that works and we can all argue about a whole new suite of anecdotal concerns.

I guess that's what I mean about mis-information.

Your ballast information is primarily related to standard compact fluorescents. Not UVB producing compacts. I get a better life our of my compact fluorescents than I do most other bulbs, except the newest T5 HO's. UVB bulbs of any type are more expensive than regular bulbs of the same type for many reasons which include a better ballast.

On the other hand, frequently on this forum people link to cheap fluorescent "shop" fixtures to use in their enclosures. Many of them have the cheapest of ballasts and indeed will shorten the life of your more expensive UVB tube.

Iron in glass is not what filters UVB. Most glass is a combination of silicone dioxide and sodium dioxide. this combination creates a band gap around 4 eV which absorbs wavelengths shorter than 310nm. That is what blocks UVB from passing through glass.

Because these lights have a compact design, no matter which type you get is designed to go into some type of hood. Whether an aquarium type horizontal hood, or a dome type fixture, that, then directs the most of the "light" towards the intended areas. They are made specifically to go into a horizontal or a vertical application.

Agree completely about the LEDs. In a few more years I think most of us will be using LEDs.

 

[counting]

Thank you for a variety of well thought out responses and perspectives.

I also very much appreciate you replying here. I know that given the search feature I can probably find out much of the answers to questions I've asked. That said, I have three kids three and under, and most of my research, reading and questions happen when I sitting in a dark bedroom. Putting kids to sleep and a few stolen moments when nursing a baby. It's extremely helpful when I can just check my thread when I get a new notification on a question, and I don't have to sort through so many pages to find the answers I'm looking for.
Thank you! - for the patience and helpfulness you've all shown with my many questions

 

[Kapidolo Farms]

https://physics.stackexchange.com/questions/247939/why-is-glass-green

 

[Markw84]

https://physics.stackexchange.com/questions/247939/why-is-glass-green

What does that have to do with blocking UVB?

I didn't say glass did not contain iron oxide. I said that is not what blocks the UVB

It's plain quantum mechanics and band gaps and looking at the electron volt of the band gap. All crystals have very specific band gaps at various electron volt levels. That allows some wavelengths to pass through while other will be totally blocked. They use that to produce very specific colored lasers with rubies or other various crystals

Glass is principally made of silicone dioxide. Silicone dioxide has a band gap of 8.9 eV. That means that would block (absorb the energy from) any wavelengths below 139 nm. That would not block UVB at all. However most all glass used is made of a mix of silicone dioxide and sodium dioxide. That combination creates a material with a band gap at 4 eV. That will totally block any wavelengths below 310 nm from passing through glass. So glass absorbs ( blocks) UVB but not so much UVA and no visible light. That addition of iron actually causes it to absorb a tiny bit of some visible light giving it a faint green tint.

 

[Kapidolo Farms]

What does that have to do with blocking UVB?

I didn't say glass did not contain iron oxide. I said that is not what blocks the UVB

It's plain quantum mechanics and band gaps and looking at the electron volt of the band gap. All crystals have very specific band gaps at various electron volt levels. That allows some wavelengths to pass through while other will be totally blocked. They use that to produce very specific colored lasers with rubies or other various crystals

Glass is principally made of silicone dioxide. Silicone dioxide has a band gap of 8.9 eV. That means that would block (absorb the energy from) any wavelengths below 139 nm. That would not block UVB at all. However most all glass used is made of a mix of silicone dioxide and sodium dioxide. That combination creates a material with a band gap at 4 eV. That will totally block any wavelengths below 310 nm from passing through glass. So glass absorbs ( blocks) UVB but not so much UVA and no visible light. That addition of iron actually causes it to absorb a tiny bit of some visible light giving it a faint green tint.

Gary Bagnall told me this was the hurdle in the development of UV's emitting tubes. That's what the German manufactures told him. Gary owns ZooMed.