Putting Mercury in CFLs in Perspective

This is an updated version of the post that originally appeared here.

I'm a fan of CFLs, but I can understand how the small amount of mercury in them can worry some. If you're worried about the tiny bit of mercury in CFLs, I can't tell you one way or another how to decide for your home, all I can do is give you the facts that are available, and let you make your own decision. What I can do though is call out those who (whether they know it or not) try to mislead others with fears about mercury.

There are three important things to keep in perspective when looking at mercury and CFLs. I covered the first 2 in our post written over two years ago titled Mercury and CFL recyling:

1: The amount of mercury in CFL bulbs is a very small amount. From our earlier post:
The biggest drawback to these light bulbs is the small amount of mercury contained in them. As stated in this handy factsheet created by Energy Star, the average CFL contains 4 milligrams of mercury. I know you’re scratching your head trying to visualize 4 mg. Remember the old thermometers you had to stick under your tongue when the “hand to the forehead” wasn’t enough. That contained 500 mg (125 CFLs) of Mercury! That’s not saying the Mercury in CFL’s doesn’t matter, it just means that we have to be reasonable with objections.
2: Many places now recycle CFLs for you! Use this handy recycle station finder from Earth 911 to find a place to recycle yo....

I hit on the number 3 thing to keep in perspective recently when we received a comment on our Best Lighting Cost Comparison post from Jackson, who is ill-informed on mercury emissions and the environment, and I didn't appreciate his smug attitude. His comment:

"Are we all so caught up in feeling good about being “Green” that we completely negate the future feelings of what it will be like to pay more for drinking water than we do for gasoline? That’s right everyone, Mercury is a poison. Perhaps Edison was right in the first place? CFL’s are what happen when you allow government to run your lives. Good luck with all your “Feelings” of saving the planet. Such small thinkers, tisk tisk. I am burning all incan’s and have enough stashed away to last me a lifetime. One thing for certain I will be greener than all of you CFL lovers."

And here was my reply:

"Hey Jackson….do tell me what part of the country you live in? Unless it’s the Northwest, I’m guessing the majority of your electricity comes from coal. From this link from Popular Mechanics comparing Mercury emitted from incandescent vs. CFLs:
About 50 percent of the electricity produced in the U.S. is generated by coal-fired power plants. When coal burns to produce electricity, mercury naturally contained in the coal releases into the air. In 2006, coal-fired power plants produced 1,971 billion kilowatt hours (kwh) of electricity, emitting 50.7 tons of mercury into the air—the equivalent amount of mercury contained in more than 9 billion CFLs (the bulbs emit zero mercury when in use or being handled).
Approximately 0.0234 mg of mercury—plus carbon dioxide, sulfur dioxide and nitrogen oxide—releases into the air per 1 kwh of electricity that a coal-fired power plant generates. Over the 7500-hour average range of one CFL, then, a plant will emit 13.16 mg of mercury to sustain a 75-watt incandescent bulb but only 3.51 mg of mercury to sustain a 20-watt CFL (the lightning equivalent of a 75-watt traditional bulb). Even if the mercury contained in a CFL was directly released into the atmosphere, an incandescent would still contribute 4.65 more milligrams of mercury into the environment over its lifetime.

3: Coal burned to produce electricity to power incandescents emits more mercury than CFLs would!

Of course this mercury is spread out in our environment, and not right in your home, but on a national policy perspective, I would encourage everyone to use CFLs so our collective environment (and thus the land we live on and the food we eat) is less contaminated. Now, if I had a small child at home, I would still use CFLs, I would just be ever vigilant to ensure the CFLs didn't break in my home. If one did break, I would follow these steps to clean up a broken CFL properly.

I just wonder if all of these people concerned with mercury in CFLs refused to put a thermometer in their mouth when they were little? Remember, an old mercury thermometer had 125 times more mercury than a CFL!!! And you put it in your mouth!!! Where was all the outrage then?

Make your own choices, but make sure you have the facts and you put everything in perspective!


So to all the Energy Pros, what do you recommend when a friend or customer asks about CFLs and why?

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Tags: CFL, and, cfls, mercury


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Comment by Brad Buscher on April 28, 2011 at 8:34am
CFLs are a better solution, both economically and environmentally, than incandescent bulbs, which ultimately result in greater mercury exposure than CFLs. While incandescents do not contain mercury, they still contribute to its release into the environment. Because burning coal to generate electricity releases mercury into the air and incandescent bulbs use more electricity over their lifetimes, they are responsible for more energy consumption and ultimately more mercury emissions than CFLs. In comparison to their incandescent counterparts, CFLs emit approximately the same amount of visible light and last 8 to 15 times as long. With a proven packaging configuration and proper disposal, CFLs can be used effectively without releasing harmful mercury vapor.


While a variety of containers are marketed for transportation of fluorescent lamps and CFLs, many don't provide sufficient protection against mercury vapor emitted from broken lamps. As this article states, consumers should properly dispose of these lamps if broken or burned out. If a lamp burns out, consumers can learn how to safely package CFLs here: vaporlok.blogspot.com/2010/05/layers-of-protection-packaging-used.html. If a bulb breaks, consumers can learn more about clean-up procedures here: www.epa.gov/cfl/cflcleanup-detailed.html

Comment by George W. Reynolds on April 14, 2011 at 6:00pm
I have been using an ultrasonic detector check for CFL's during HERS rating and am surprised by the high 20+ kHz output of CFL's in reflecting cans. I wonder if anybody has studied the sonochemical effects on the body since it has the ability to generate oxidants from water, not to mention hearing impairment?
Comment by Kim Urig on April 11, 2011 at 5:13am

I liken the CFL to the incandescent, what the cassette tape was to the LP. An intermediate step to where we eventually will be. I think the future is in LEDs, though they need to come down in price. I first started using CFLs about 6 years ago, just replacing each bulb as it burned out, one at a time. We've never broken one, but we do make sure we dispose of them properly, we've had maybe 3 burn out in that time. I simply don't see why folks would want to pay more on utilities, so for me the answer is purely about economics.  I like to save money. Here are a few post I've made in the past on the subject: 





Comment by Dennis McCarthy on April 8, 2011 at 10:14am

The use of cfls should be viewed this way - how many more decades will they be around. One

Are they being phased out for a variety of reasons - absolutely!

How much mercury should you come in contact with - zero - it IS a neurotoxin

What will chase the cfl mfgs out of existance - LEDs circa 2011- 2015

Cfls are a 20th century solution and as we are living in the 21st century - let us

get on with the migration to SOLID STATE LIGHTING already!

Comment by Evan Mills on April 6, 2011 at 3:51pm
Comment by Chris Kaiser on April 6, 2011 at 12:14pm
Evan, that is probably one of the best articles I've seen on the issue of mercury in CFLs and putting it in comparison!
Comment by Evan Mills on April 6, 2011 at 10:51am

Think of it as one very small nibble of swordfish....


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