Lighting topics don’t get much more exciting than the debate over the mercury content of compact fluorescents (CFLs). Those against the use of CFLs claim that the potential harm of toxic mercury contained within the energy-saving bulbs far outweighs any environmental benefits. On the other side, groups feel such rhetoric is overblown. But what are the facts?
Why Use Mercury in CFLs?
Mercury (Hg) is a naturally occurring element used in applications as varied as thermometers, dental fillings, and fluorescent lighting. The cathodes within a fluorescent tube produce electric current that passes through argon gas and mercury vapor. In turn, the mercury vapor emits ultraviolet light that excites the phosphor coating within the fluorescent tube, producing visible light . The technology is the same for both linear fluorescent tubes (like those seen in office buildings) and self-ballasted compact fluorescents (the “spiral” bulbs used in homes). In short, without mercury, fluorescent lights will not work.
How Much Mercury is in a CFL?
The amount of mercury contained within a CFL varies, and in general, has decreased since their introduction nearly two decades ago. As of November 2010, the US EPA’s Energy Star program concluded that the average amount of mercury within a screw-in CFL was 4 milligrams, comparable to the size of a ballpoint pen tip . This pales in comparison to older thermometers, which contain as much as 500 mg  and even amalgam dental fillings, which contain about 100 mg of mercury .
Mercury Content in Popular Items
Keep in mind, however, that the mercury contained in a CFL, thermometer, or dental filling can be present in these sources in two forms: A liquid, which is what we typically think of when we think of mercury, and a vapor that quickly dissipates. In the case of a broken CFL, the most likely form of exposure comes from inhaled mercury vapor. A paper in the August 2009 issue of the lighting journal LD+A found that the median amount of mercury vapor to which a person is exposed through a broken CFL is a tiny fraction of the total mercury contained within the bulb: Approximately 0.07 micrograms (0.0007 mg). On the other hand, a tuna fish sandwich, which contains the more hazardous methylmercury, is estimated to expose the consumer to more than 48 times that amount due to the more efficient method of consumption (literally eating the mercury) .
Who Regulates Mercury in CFLs?
Despite its relatively low concentration in CFLs, mercury is still a toxic substance. For this reason, the EPA requires that CFLs contain no more than 5 mg of mercury for consideration in their Energy Star program. The European Union and the State of California adopted even tougher regulations, requiring CFLs to contain no more than 2.5 mg of mercury by 2013 . Manufacturers, however, have made the biggest strides. A 60-watt equal, warm white Neolite CFL by Litetronics, for example, uses only 1 mg of mercury, 80% less than Energy Star requirements . Along with other major manufacturers, Sylvania voluntarily capped CFL mercury content at 4 mg, with the 13-watt DULUX EL 29409 containing only 1.5 mg .
So the question remains: Is the mercury in CFLs dangerous? It’s not an easy question to answer. Mercury is a toxic substance, yet it is unlikely that fluorescent lighting would ever expose a person to an amount of the neurotoxin sufficient to cause physiological harm. Want proof of that? Despite putting themselves in a worst-case scenario fluorescent lighting mishap, to the best of our knowledge, these two guys are still alive and well:
Today’s article takes a slightly different approach than usual. One of the questions we often get here on the blog and in our Wednesday Lighting Q&A on Facebook is about energy-saving bulbs. Specifically, people want to know what defines an energy-saving light bulb and what makes an LED better than a CFL, a CFL better than a Halogen, or any variant on that question.
With that in mind, we’ve recorded a short, introductory video that we hope will answer most of your questions. Of course, we’ll gladly answer any remaining questions you may have in the comments section below, on our Facebook page, or on our Twitter or Google Plus accounts. You can also check out our related Squidoo article, also titled “Energy-Saving Light Bulbs.”
So grab some popcorn and sit back! (Assuming that’s OK with your boss)
Welcome to 1000Bulbs.com, the Internet’s number one retailer of light bulbs and lighting products. In today’s video, we’ll be discussing a very popular but often misunderstood topic: Energy-saving light bulbs.
“Energy-saving” is a term thrown around pretty often these days, especially referring to light bulbs. But just what is an energy-saving light bulb? Though there is no strict definition of an energy-saving bulb, one thing is certain: It must be more efficient than an incandescent bulb. That said, energy-saving bulbs fall into one of three product types: Halogen light bulbs, compact fluorescents (more commonly known as “CFLs”), and light-emitting diodes, better known simply as “LEDs.” Let’s look at each bulb type one-by-one to understand their benefits.
First, for reference, we have incandescent light bulbs. Though they’re old technology, they’re still very common. On the plus side, incandescent light bulbs are inexpensive and completely dimmable. However, these attributes are overshadowed by how inefficient they are as well as their short lifespan.
Next, we have the first of our energy savers, the Halogen light bulb. You’ll notice that these look very similar to incandescent bulbs. Also like incandescent bulbs, Halogen bulbs are inexpensive and dimmable. However, Halogens only last about 1,000 hours, and they’re only 15 to 20 percent more efficient than incandescent bulbs.
Now we have the compact fluorescent, which is probably what you think of when you hear about energy-saving bulbs. CFLs have many positive attributes, including being relatively inexpensive, at least in comparison to LEDs, as well as lasting eight times longer than an incandescent or Halogen and using about 80% less energy than an incandescent bulb. Unfortunately, most compact fluorescents are non-dimmable. They also contain a small amount of toxic mercury, so they have to be recycled, and some people find their characteristic spiral shape off-putting.
Finally, we can discuss LED light bulbs. Not only are these the most efficient light bulbs available to homeowners, they last 50,000 hours or more, and most models are fully dimmable. Of course, anything has drawbacks, including LED. These bulbs are an emerging technology, so manufacturers are still working out some of their “kinks.” Also, as a new technology, LEDs are still relatively expensive, though their prices are dropping rapidly as technology improves.
So let’s look at these four bulbs side-by-side: An incandescent bulb produces 13.3 lumens–the standard measurement of light output–for each watt of energy used. A Halogen light bulb is only slightly more efficient, producing 16 lumens per watt. Compact fluorescents, however, make a huge leap in efficiency, producing 61.5 lumens per watt. But by far the most efficient is LED, which produces nearly 90 lumens per watt!
Many people in lighting and design circles are already familiar with the Plumen CFL. If you’re not, Plumen’s tagline sums it up pretty well: “The world’s first designer energy saving light bulb.”
To many, the typical spiral shape of a compact fluorescent is an eyesore, so they hide it under a lampshade or within an enclosed light fixture. That’s unfortunate, because there’s no reason a CFL has to be so ugly. In fact, the bulb’s glass tube can take virtually any form. There are plenty of fixtures, from pendants to desk lamps, which challenge the status quo. Why shouldn’t a bulb do the same?
The creators of the Plumen—designer Samuel Wilkinson and British design company Hulger—took that challenge. Their revolutionary bulb takes its inspiration from bird feathers (the “plume” in Plumen). Instead of twisting the glass tubes of the bulb into a utilitarian and industrial shape, the designers gave them an airy, organic form. The unique design has already landed Plumen in the permanent collection of the Museum of Modern Art (MOMA) and earned it the Brit Insurance Design of the Year Award.
Popular applications for the Plumen include pendant lights, floor lamps, and anywhere you might use an antique light bulb. Indeed, many stylish, yet energy conscious customers find the Plumen satisfies their desire for much less efficient incandescent antique bulbs. The Plumen uses only 11 watts to produce the equivalent light output of a 60 watt incandescent light bulb. This means the bulb saves 80% on your energy bills. In addition, the 8,000 hour bulb will outlast 8 to 10 incandescent bulbs. Lower bills, fewer carbon emissions, long life, and beautiful design: What more could you ask for in a light bulb?
You know the feeling. You just came home from the hardware store with a blister pack of brand new, energy-saving CFLs. You screw them in and hit the switch. “Oh, this is gonna be good,” you say to yourself. You’re going to save tons of money and your bulbs are gonna look great! Then you notice they’re dim, really dim. Defeated, you retreat to another room to find your receipt. But then, when you return a minute or so later, they’re as bright as you expected them to be! What sorcery is this?
Everyone has had this experience with their first batch of CFLs, though maybe it wasn’t as melodramatic. To understand why compact fluorescents start off dim, you have to know a bit about how fluorescent lighting works. Unlike an incandescent bulb, which creates light by heating a filament until it is white-hot, fluorescent lights use cathodes to heat a special gas or mix of gases to create UV light. The UV light is then filtered through phosphors to create white or colored light. To do this however, the cathodes have to warm up.
Every new CFL on the market uses different proprietary technology to shorten the bulb’s warm-up time, with varied results, so we chose to test four of our best-selling 60 watt CFLs. Though this is far from a scientific study, here’s how we conducted the experiment: We screwed each bulb into a lamp, and set a light meter about one foot to the side the lamp. We propped up the light meter so it was roughly on the same horizontal plane as the CFL’s midpoint. We then turned on each bulb and used the light meter to record the maximum light output of the bulb. Finally, we replaced the bulbs with identical bulbs of the same make and model (using the already warm bulb would have skewed our results). We then switched the bulbs on and recorded the time it took to meet the previously recorded maximum output.
Bulb One: Energy Miser
The first bulb we tested is a 13 watt, 2700K CFL from Energy Miser. Just over $1.00 each, this bulb is not only the most inexpensive of the bulbs we tested, but it’s also our best seller. The manufacturer doesn’t make any claims about the bulb’s warm up time, though our customers have given it an average 5-star rating. In our tests, the bulb reached its maximum output in 2 minutes, 2 seconds. That’s not exactly quick, but according to most manufacturers, it’s about on par for a typical CFL.
Bulb Two: TCP TruStart
The second bulb we tested, a TCP TruStart, is a fairly new addition to our product line. In their spec sheet, TCP claims this bulb is the “Best on/off CFL ever made!” Unlike the previous bulb we tested, TCP does make a claim about this bulb’s warm-up time; specifically, TCP says the CFL has a less than 30 second warm-up time. Our tests showed this claim to be mostly true, with the bulb reaching its full brightness at 38.7 seconds.
Bulb Three: Sylvania DULUX EL
The third bulb we tested is from the “big three” of lighting manufacturers, Sylvania. Sylvania also doesn’t make any specific claims about warm-up times for this 13 watt CFL from their DULUX EL family, nor do our customers (who give it an average 4-star rating). So how did this name brand product fare? Pretty well, it turns out. The bulb reached its full brightness at 1 minute, 7 seconds. That not as good as the TCP TruStart, but it’s nearly twice as fast as the Energy Miser.
Bulb Four: TCP InstaBright
The final bulb we tested is a little different from the other four we tested. This covered CFL from TCP has a glass cap over the fluorescent spiral tube so that it looks more like a typical A-shape incandescent bulb. In their InstaBright G2 brochure, TCP claims the bulb has the “Fastest run-up time and significantly improved light build up time,” and it is supposed to reach full brightness in 45 seconds. Surprisingly, this bulb beat even its own estimates, reaching full brightness in only 35.1 seconds!
Which of these bulbs should you buy? It depends how much you’re willing to pay and how much you value fast warm-up times. There is a spread of more than $4.00 between the cheapest and most expensive of these bulbs. Is a few seconds quicker to reach full brightness worth the premium? Let us know what you think in the comments, or connect with us on Facebook, Google+, and Twitter.
Whether you’re shooting at friends in a laser tag arena, venturing through the narrow passageways of a haunted house, or simply watching your favorite episode of CSI, black lights never cease to amaze. There’s something fun and mysterious about revealing secrets and hidden messages with that strange purple light. But how do black lights work? (Hint: It’s not magic.)
The signature glow produced by black lights requires two separate things: A source of ultraviolet light and a surface coated with UV-reactive phosphors. The source of the light is a bulb, whether incandescent, fluorescent, CFL, or LED. You can find phosphors—a loose grouping referring to special compounds and minerals—in and on all kinds of things: Highlighters, soap, rocks, glow-in-the-dark toys, and even your teeth. When ultraviolet light hits a phosphor, the phosphor glows in a phenomenon called luminescence.
Incandescent Black Lights
You may remember from our previous article on yellow bug lights that the short-wavelength spectrum of light beyond visible light is ultraviolet light. All light sources produce UV in varying quantities. For example, the simplest form of black light, an incandescent black light, produces very little ultraviolet light but uses a special filtering glass called Wood’s Glass to block most visible light produced by the bulb filament, thus enhancing the effect of the UV spectrum. However, the relatively small amount of UV light incandescent bulbs produce makes incandescent black lights the least impressive of black lights.
Fluorescent Black Lights: BL vs. BLB
Fluorescent light sources naturally emit much more of the ultraviolet light spectrum, making the technology ideal for use in black lights. Fluorescent black lights fall into two different categories, black light (BL) and black light blue (BLB). Fluorescent black lights use special phosphor coatings on the inside of the bulb to filter out visible light and enhance the emission of ultraviolet light. In both BL and BLB technologies, this ultraviolet light causes external phosphors in its surroundings to glow, just like an incandescent black light does. However, because fluorescent technology produces much more of the UV spectrum, fluorescent black lights are more effective than incandescent black lights.
While both a fluorescent black light and a black light blue use UV light and phosphor coatings to create luminescence, the difference between them is how much invisible ultraviolet light they emit in relation to visible white light. A fluorescent black light, which appears similar to any ordinary white fluorescent lamp, emits a relatively large amount of white light mixed with ultraviolet light. The light from a fluorescent black light looks similar to what we are used to from ordinary fluorescent sources, yet still causes limited luminescence of external phosphors.
Black light blue fluorescents are much more commonplace. Like other fluorescent black lights, they use a special phosphor coating to filter white light; however, for more complete blocking of white light, black light blue bulbs also are made of a purple-colored filtering glass. This combination allows them to emit a greater amount of ultraviolet light than white light. The result is the familiar purple-colored light and a very pronounced luminescence of phosphors in black light reactive objects.
Other Black Light Technologies
Of course, fluorescent black light technology lends itself equally well to compact fluorescent black lights. Though compact, CFL black lights work according to the same principles of black light or black light blue fluorescent lighting. LED black lights are less common, though they are starting to emerge, especially in stage and nightclub lighting. Other niche applications include HID lighting, especially mercury vapor, and “bug zapper” lights like the Paraclipse Mosquito Eliminator.
We hope we haven’t completely destroyed the mystique of black lights for you. But if we have, be sure to let us know in the comments, or drop us a line on Facebook, Google+, or Twitter page.