Fluorescent lights

Lots of countries have or will mandate the use of low-energy light bulbs. That's it, for the incandescent bulb. Soon it will be just compact fluorescents or LEDs or whatever comes next. Along with this comes the inevitable news articles that start, "Health experts are warning that . . . ":

The Government's planned switchover from traditional light-bulbs to low-energy lighting could cause health problems for tens of thousands of people with skin conditions including eczema, experts have warned.

And there were warnings that consumers will have to take more care disposing of broken or expired low-energy bulbs in order to avoid contamination with the poisonous mercury they contain. (The Guardian)


The fluorescent devices produce a more intense light and can aggravate a range of existing problems, especially in those with light-sensitive conditions.

Eco-bulbs are due to become compulsory in British homes within four years. But campaigners want the Government to allow an opt-out so people with health problems can still use old-style incandescent bulbs.

Energy-saving bulbs 'can cause migraines' warn experts
There have been growing concerns that low-energy light can trigger migraines, as well as dizziness, loss of focus and discomfort among those with epilepsy.

There have also been complaints from sufferers of lupus - an auto-immune disease causing many symptoms including pain. (The Daily Mail)

There's lots more articles of this genre, once you start looking for them. So is it a concern? That sent me reading a bit about fluorescent lights, something I knew about only in the vaguest way. It didn't answer the question but it told me something about why there is one.

How do these things work? Conventional incandescent bulbs work by heating a metal filament to, well, incandescence. The filament is really a resistor and as it resists the current flow it gets hot. Hot objects radiate electromagnetic radiation, the hotter the object, the higher the average frequency of the emitted EM (Wien's Displacement Law). That's all you need to know about it because that's not how fluorescent lights work. Fluorescent lights work by using electrical energy to knock electrons of a substance like mercury into higher energy orbits. It's like pushing one of the outer planets of our solar system, say Neptune (I almost said Pluto, but . . . ), into an oarbit much closer to the sun. Neptune doesn't like it there and will fall back to its old orbit at the first chance it gets, releasing the energy you used to get it close to the sun in the form of EM radiation, i.e., in the form of light.

Unfortunately it isn't light we can see. It's in the ultraviolet range (UV). The UV then does the same thing to a phosphor on the inside of the fluorescent bulb, bumping one of its electrons into a higher orbit, which, when it falls back to the original lower energy orbit also releases EM radiation. But this time the energy is in the visible range. Voila, a fluorescent light!

Depending on what kinds of phosphors you have in these bulbs you will get a mixture of different light frequencies. There are people apparently quite sensitive to some EM frequencies (they are even highly sensitive to sunlight) and lupus sufferers are also photosensitive. So the new mix of light frequencies (i.e., a mix different from that of an incandescent bulb) could conceivably create a problem for a small segment of the population. This has been little studied and most of what we know comes from case reports. I don't have a reason to be skeptical, however. It's certainly plausible. The leakage of UV could also conceivably be regarded a skin cancer hazard (I'm not sure how much of the first stage UV actually gets out).

The question of migraines and epilepsy is related to the potential for flicker. Incandescent lights don't flicker because, while the electric energy is surging through it in a flickering pattern (120 times a second, 60 times each direction (50 times in Europe), the filament doesn't cool fast enough to change the illumination. In fluorescent lights there is a more complicated picture. Turning the light on takes more energy than keeping it lit. In fact the resistance to current flow is highest at the outset but once the current starts through the rarefied gas the resistance decreases. It's a positive feedback. A little current decreases the resistance, which makes the current increase, which makes the current flow bigger which decreases the resistance further and, if you didn't put a damper on the process, the whole thing would blow up. The damper mechanism is provided by a device called the ballast and there are several different kinds. The most common ones in the long fluorescent tubes we see most often in office buildings are separate devices that work on a magnetic principle, sort of like electrical springs that store the energy in the electric pulse's in-stroke (in either direction) and release it on the outstroke. This smooths it out and prevents the process from stopping each time as the voltage passes through zero and also prevents it from blowing up. The "compressed spring" exerts a back pressure. With this kind of ballast operating straight off the electric mains there is still a 120 cycle per second change in illumination, too fast to see (we don't see flicker past about 50 cps), but apparently enough for some people's nervous systems to register in the form of headaches or fatigue. At least there seems to be a fair amount of anecdotal evidence of this and I don't have a strong reason to disbelieve it. On the other hand, while you can induce grand mal seizures in epileptics at low frequency strobe cycles, I think 120 cps is way too fast for this so I am a bit skeptical of the epilepsy hazard.

What about the low energy compact fluorescents that will presumably take the place of the incandescent bulbs in most of our homes in a few years if the mandates come into force? The big innovation is the ballast. It is a microelectronic device built into the base or socket part of each bulb instead of being separate as it is for the long tube affairs (the tubes don't have ballasts on them). That's why you can sscrew them into the socket. These ballasts also operate at much higher frequencies than the mains supply, somewhere around 20,000 cycles per second instead of 120. Thus they should be essentially flicker free.

What all this means to me is that there are enough ways to adjust the flicker and the light spectrum so that we can make low energy fluorescent lights that don't have serious health consequences (that doesn't mean we will, of course). Moreover there will likely be other low energy options, like LED I(light emitting diodes) in the future as well.

Of course that won't stop some health experts from warning that . . .

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Compact fluorescent lamps (CFLs), or "energy saving light bulbs", are much more energy efficient than conventional light bulbs, and they have a significantly longer lifetime. On top of that, replacing your conventional bulbs with CFLs won't just save energy, but will also save you money. Most…
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I've noticed my digital camera picks up the UV leakage on the CFL's I've got. The camera also does infrared quite well. I wish I could get at the firmware of the thing and set the iris to stay open because if I could do that, I could do some infrared astro photography.

If there is enough money in it you can get a Doctor or someone who plays one of TV to say anything you want. Just a fact of life today. So if the electric company thinks that too many people are changing out their light bulbs and they are not making enough money then the hue and cry will begin. Sounds too much like requiring solar panels on all new construction to be wrapped into the cost . In the long run the owner would save money but..

I have experienced that flicker effect first hand, and let me tell you it isn't pleasant. A couple of years ago I spent several months suffering from labyrinthitis and ocular migraines after a URI. I've never had migraines before or since, but it was scarey. I could be walking down a hospital corridor or shopping in a big box store, when I could drag myself out of bed, and experience an aura from that flicker effect. Sometimes I would lose my vision altogether and feel nauseated. I had no clue what was causing it at the time. It took them a long time to tell me what was wrong with me.

As someone who has experienced it, I can sympathize with folks who have troubles with fluorescent lighting. On the other hand, I have used the fuorescent bulbs that screw in the way an incandescent bulb does for years with no ill effects. They did not seem to bother me when I was sick like the fluorescent tubes. They don't seem to cause the flicker the tubes do. Even now the fluorescent lighting in big box stores and hospitals make me queasy, but it's probably a throwback to my bad experience with them when I was sick.

By Rebecca S. (not verified) on 07 Jan 2008 #permalink

Regarding the leakage of UV

I don't know about under ideal circumstances, but the coating on some bulbs in a gym was bad while I was in college. A number of people got badly "sunburned" and that was how the problem was discovered.

I sort of like the idea of the compact fluorscents, but the practicality is lost in my apartment. For some reason, they blow out faster than incandescents in my place. I also keep the winter temps low enough that the darn things won't come on fully in some rooms. Somehow I suspect that I use less energy by keeping the temps low and lighting with incandesents than I would by keeping the room warm enough to get the light I need out of a CFL.

I kind of like having the two stories of outdoor stairs lit on icy nights too, so I'm not planning on putting them in the outdoor fixtures anytime soon.

Yeah, I'd like to see some exceptions. Actually, I'd like to see the legislated switch go away.

I also wonder about the preconsumer energy costs on the different types of lights (transport, materials, manufacturing), as well as disposal issues. No one seems to want to talk past the hype of using less energy in your home/business. Is the savings really that great when everything is factored in?

Typically today, offices (especially cheapskate ones) will use the older style florescents with a slow frequency and a pretty unnatural, greenish light. The tubes are cheap and widely available in bulk.

But the compact ones and higher-quality tubes, especially newer designs, are quite different. As you say they don't flicker at all anymore, and the light color is tuned much better - you can choose whether you want reddish orange ones that mimic incandescents, or "natural light" ones that mimic sunlight and does it well enough that they work as growing lights for plants. If you have problems with florescent lights, just stay away from the old-style cheap ones; if you have trouble with it at work, ask them to change them - it's a workplace environment issue after all.

And high-quality ones do not have problems with ambient temperature. If they did, places like my hometown in Sweden could not use florescent street lights in mid-winter. Like with everything, stay away from the cheap cr*p.

And Karen: yes, the savings are pretty considerable, even after you factor in production cost, heat generation (most heat from incandescents get dumped up in the ceiling where it does nothing good for anyone and it adds additional load for cooling in summer), transport cost and disposal (disposing one florescent costs more, but you're dumping a lot fewer since they last longer; you also transport a lot less of them).

Over longer time, expect LEDs to take over, of course. Even more efficient, much more long-lasting and easy to use in much more diverse formats than earlier lighting types. How about sunlight-white LEDs ringing the inside of your windows, angled to bounce of a slightly frosted inner pane? Light them and you can have a "sunlit" room at any time of day or weather.

We pride ourselves on running an exceptionally energy-efficient household.

All primary lighting is dimmable. All hallways and rooms which are transitable from one door to another have a switch at each door (an internally illuminated switch which can be seen in the dark).

The idea is that when moving through the house at night, as one enters a room in which one will not be staying, the light is turned on at the entryway door, comes on dimmed but bright enough to navigate pleasantly, and can then be shut off at the exit door.

Simple, no? No. Not when CFLs get into the loop. Because even the best ones take up to five seconds to illuminate (especially when they are cold, and we set the thermostat very low in the wintertime). In five seconds you can walk far enough into a darkened room to fall over something unseen in your path.

So we are reliant upon halogens and/or incandescents. And now it is proposed to ban them. Bah.

I'm a green diaper baby whose parents were taking me to Sierra Club meetings *way* back before that organization even entered general public consciousness. And I'm still green, but I am increasingly frustrated and pissed off with clumsy, technologically ignorant, dirigisme restrictions on use. Give me a watt-hour target and I'll meet it. Don't tell me how, damnit!

I have friends who proudly boast that all of their lighting is CFL. And who leave all of it turned on, all of the time. Not a big improvement in my book. In our house, the only rooms which are lit are those which are occupied.

Oh, and count me among those who end up with a headache from trying to read under fluorescents. It made my pre-college education truly miserable in the classroom.


I have actually seen fiber-optic wall paper that costs nearly nothing to operate. 10 cents per hour and its only drawback is that its hard to connect to the switch, but you can literally light up a room high enough to get a tan off of four panels of this stuff. No heat at the surface.

But its just a matter of time before someone says that F bulbs cause cancer or the mercury is too high and we have switch to the LED's because they are better. They are less expensive but as usual there isnt enough study before our Congress acts on it.

How many people here use their V-chips?

By M. Randolph Kruger (not verified) on 07 Jan 2008 #permalink

marquer says: Give me a watt-hour target and I'll meet it. Don't tell me how, damnit!

I think you are misinformed. This is *exactly* what the legislation does, at least in the US. It sets an efficiency standard (not a technology standard), and any bulb that meets it is fine. The bar is simply too high for incandescents to meet. LEDs and CF have no trouble meeting the bar.

marquer says: Because even the best ones take up to five seconds to illuminate (especially when they are cold, and we set the thermostat very low in the wintertime).

I think you should go check out some modern bulbs. Our bulbs from 3-5 years ago light up just fine in well under a second, up to about 75% capacity. There is, maybe, a barely perceptible pause when turning them on. After a few minutes they are up 100% power. The instant-on capacity is plenty bright enough. And yes, we keep our house cold too (45-55 F at night, 60-65 during the day).

marquer says: Oh, and count me among those who end up with a headache from trying to read under fluorescents. It made my pre-college education truly miserable in the classroom.

Don't be an idiot. That is like grandma saying "I'm sticking with horse and buggy, because those crank-engine cars I remember growing up were just too damn hard to start." In 2008.

Karen: Is the savings really that great when everything is factored in?

From everything respectable I have read, yes, it is. I think you haven't even tried to find an answer to your question, though, because the answer is easy to find. Try google. And do recognize the quack sites when you see them.

Although I really really hate the flicker of old-school fluorescent lights (I'm very very aware of it. I also sometimes start see series of individual frames in movies) I prefer some cfl's to incandescent. Incandescent are too orange.

Can you get high frequency ballasts for the long tube style of fluorescent lights?

I sort of like the idea of the compact fluorscents, but the practicality is lost in my apartment. For some reason, they blow out faster than incandescents in my place.

I've been using CFLs almost exclusively since I moved into my house seven years ago. The area I live in has had several power outages of the sort that play merry hell with electronics. The last one, the Saturday before New Year's, cost me the motherboard of my Linux server and an outboard USB hard drive. And both of these were buffered by an intervening 1250 VA UPS.

The wear and tear on CFLs has been nontrivial in these incidents. The outage of December 29 cost me two 42 watt CFLs of the older "long U" design. Four years ago, a power outage took out a GE "Profile" floor-standing fluorescent lamp, and a year prior, I lost another one the same way.

I have never seen this sort of outage-driven attrition with incandescent bulbs. And I have lived in several areas where sudden and "nasty" (multiple surges during the shutdown) power outages have been commonplace.

OTOH, I can stick a 13 watt (60 watt equivalent) CFL into a socket that was seriously overheated by an incandescent, and let it run 24/7. I can also put much more light into a room with much less waste heat.

Personally, I never plan to go back to incandescents except in places where a CFL cannot practically be deployed. That being said, I would much prefer that legislative coercion NOT be injected into this process without some actual NEED.

The cost/benefit ratio should be sufficient to ram the point home. Subsidy by local power companies, which was common in Metro Seattle three or four years ago, will also help. I must have bought at least two dozen 13 watt CFLs, back when they were $0.25 apiece, courtesy of the Snohomish County P.U.D.

By Charles Roten (not verified) on 07 Jan 2008 #permalink

Compact florescents also don't work in the cold. I put them in my chicken house last summer when I needed a new lightbulb, but they barely come on when it's down below freezing. It's like working in feeble candle light.
Instead of legislating regular bulbs away, can't they just make them more expensive than the florescents and let the market do it's job?

I, too, have flicker disease (I can even be uncomfortable driving through trees in winter). However, the new florescents don't bother me, expecially if I choose the color I need for where they are placed.
I also keep them in outdoor lights, turn on at dusk, off at dawn. It is important for security where I live to have dependable outside light. The one I put out 4 years ago is still ok.

BTW, I live in a cold climate

TwoCrow, you can buy outside CFLs almost anywhere. I have two on my porch and they work at 20 BELOW zero.

By G in INdiana (not verified) on 08 Jan 2008 #permalink

Thanks, G! I look forward to them reaching my local store here in the back of beyond.

I replaced all my inside bulbs and stockpiled the incandescents for the chicken barn. It's nice to know that I'll have something to use when they run out.

I like the dim-at-first feature of CFLs. At night when I get out of bed they don't blast me awake, they brighten up as I wake up. The old ones were slow but the newer ones are quite quick. My husband complained that they were too bright until I shopped around for 40 watt output bulbs.

My household already converted to almost 100% fluorescent lighting. We've been slowly doing it for years. There's a CF bulb in the hallway that cost nearly $20 when it was new, probably twenty years ago. At temperatures of 55F or above, most of the Edison base CF lights turn on in one second or less, with slow ones taking up to two or three. I just looked at a package of GE CF bulbs, and they are rated to 5F or -15C. At 11 cents per kilowatt.hour, a 23W CF bulb replacing a 60W incandescent will save over $4 in electricity costs every thousand hours, and will typically outlast a number of incandescent bulbs with a higher total cost.
However, the brightest CF bulb I've yet to find is significantly less bright than the 70W quartz halogen bulb I used to have in the garage. Now, to get the same light at the washer and dryer that I used to get for 70W, I have to turn on additional, more distant fluorescent lights for a total of 106 to 146 Watts. Also, in a package of brand new CF bulbs that I bought in 2007, I've found more than one that flicker and whine unacceptably. My bathroom light fixture thus has one CF that doesn't flicker and one 60W incandescent that also does not flicker.

S.o.G asked:

Can you get high frequency ballasts for the long tube style of fluorescent lights?

High frequency ballasts are becoming more common for long tube (40W) fixtures. Look for the phrase "electronic ballast". If you buy a replacement ballast and it has a plastic case, it is almost certainly electronic and not magnetic. The IC chip, transistor, circuit board and other parts of an electronic ballast are cheaper to buy and assemble than the large iron-base core and many yards of copper wire of the original magnetic style ballast and they eliminate the need for a separate starter relay. The high frequency also causes the fluorescent bulbs to emit more light for the same amount of electricity, and the energy losses in the electronic ballast are typically less than those of the magnetic ballast.

However, a long fluorescent fixture with an electronic ballast may still flicker at 50/60 cycles, occasionally even worse than a fixture with a well functioning bulb and magnetic ballast. Why you ask? The power supplied to the fixture is alternating current. The voltage varies in a sinusoidal manner 50 or 60 waves per second, depending on where you live. Twice in each cycle, the supplied voltage drops to zero. In a fixture with an inductive (wire-wound) ballast, the ballast stores energy when the (absolute value of the) voltage is high, and releases it when the value is low or zero. Electronic ballasts store less energy, but do a far better job of regulating flow of power into the bulb at the times where the supplied voltage is not near zero. In fixtures using linear tubes, flickering can often be eliminated by replacing one or more of the tubes. Bulbs that are defective or degraded by age and use can behave in odd ways that the ballast is unable to compensate for.

I've seen bulbs with spiraling or waving patterns of light, bulbs that blink on and off in a regular pattern, bulbs that pulse like a strobe light, bulbs that flicker and cause the ballast to hum, and even bulbs that would not turn on in the dark but would suddenly blink on if you struck a match 20 feet away or turned on a stove burner or shined a flashlight on them.

By Dangerous Dan (not verified) on 09 Jan 2008 #permalink

Bit off topic.. I know someone who suffered headache (or migraine?) and the cause was found by accident, so to speak. It was his beamer - oops, meaning, video projector, that produced flicker. These devices come labelled with p or i (small p, small i.) These refer to two different methods of creating/refreshing the pixels that make up the picture. P stands for progressive, the image is created line by line, in one direction (such as on your old TV.) I is for interlaced: odd (or even) lines in two directions, vertical and horizontal, are created, with the second sweep doing the remainder, even (or odd) lines. It is said that progressive creates, or can create, flicker, or more flicker than interlaced, or more flicker than an ordinary tv (as various other factors: number of lumens, size of screen, position of beamer, etc. etc. interact, whereas the tv has been designed for optimal viewing with that technology) which kind of makes sense. However, this is a specialised area an I am no expert, I only mention it because it might be worth remembering.

Regarding the 'florescent light epileptic seizure' concern, it does exist based upon person experience.

I have suffered many grand mal seizures even though I am not diagnosed as epileptic; I am simply pre-disposed towards seizures according to the multiple neurologists and their extensive EEG fun they have had with me over the course of many years.

Regarding florescent lights, due to my grand mal "disability" I have become fairly adept at noticing pre-seizure symptoms. A certain food outlet chain, I am assuming, must use the same supplier for their fluorescent lighting. I can enter into that particular chain of stores and within thirty to sixty seconds will begin to see pre-seizure warning signs such as multi-colored "aura's", nausea and limited mental disorientation. I will leave the store and the symptoms quickly if not immediately disappear. Other chain stores do not induce this symptom even though they use florescent lights within their stores however I have noticed this phenomenon in various airports around the United States.

In summary, while I cannot state the percentage of the population with this rather unique disability, the "florescent light seizure risk" is certainly a real one for myself and is one in which I must be cognizant of when entering new stores or airports.

Matt: There seems to be ample evidence of the usual fluorescent lights doing this to some people with seizure disorders. My comment was limited to the new compact variety that have a high frequency ballast built in to the socket.

Energy efficient light bulbs are the easiest first step consumers and businesses can take towards reducing their energy consumption. Products have gotten light years better in the past few years and, in my eyes, indisputably better for 99% of applications. Both CFL and LED light bulbs run much cooler than incandescent bulbs, use energy much more efficiently, and do offer saving on your electricity bill. I am a vendor of energy efficient bulbs, so perhaps I am a bit biased, but I don't know why everyone doesn't switch today.

I have epilepsy and I can state for a fact that fluorecent bulbs can have an effect on a person with my condition. I experience nausea, headaches, and an aura sensation from even a few moments of exposure to fluorescent lighting. That being said I'm not in the least bothered by watching tv or playing video games. I can only guess that something about the flicker of the bulbs reacts negatively with my brain, as I am not cognitively aware of the flickering outside of the onset of headaches and nausea.