Mercury in CFLs in Context

CFLs have once again received a battering in the press this week with the BBC headlining three articles over three days over claims of their impact on their health.

The three articles were;

Low-energy bulbs 'cause migraine'
Low-energy bulbs 'worsen rashes', and today;
Low-energy bulb disposal warning

As I watched rolling news this morning on BBC Breakfast at 6am, they offered a three minute report, which whilst balanced (and needed to be entered into the public domain) bordered on alarmist, played back every thirty minutes with discussions with Dr David Grey, a toxicoligist from the University of Nottingham, and Louise Molloy of Greenpeace, on two seperate hours in the morning.

Having written an article on mercury in CFL bulbs, which is also available on the BBC Action Network, I was more than aware of the fact mercury was contained within, and not only that I have on several occasions called for adequate information regarding mercury content, recycling information and clear up information to be added to packaging and the dissemination of information of information to the public, which is seriously lacking, as 99% of us never read the packet anyway. People probably think I am getting sidelines from CFL manufactures to fight the mercury issue, however unfortunately I am not, I wish I was. CFLs are old technology, and if you can get you hands on LEDs at an affordable price, this makes a better choice over CFLs.

With Energy Star Canada citing the average CFL contains 3mg of mercury, placed in context with other household appliances CFLs are the least of our worries with the following containing mercury in far greater weights, some several hundred or times more than a CFL;

LCD Monitors
Thermometers
Thermostats
Mobile Phones, and
Dental Fillings

For a list of items in your home that could contain mercury the EPA has provided a short but not extensive list.

Whilst I am not saying mercury is safe, it is a deadly neurotoxin after all, I am trying to put your mind at rest that the amount contained in these bulbs is in relative terms only a small proportion of the mercury found in the home. CFL bulbs do not often break unless subjected to abuse, for example I have seen bulbs dropped from a reasonable height on to a solid surface, the bulb and its glass remained intact.

Even if the bulb was to break, one study looking at long tubular fluorescent bulbs found that over a two week period, only 17 to 40 percent of the mercury in the bulb evaporated. The rest remained stuck in the bulb. Roughly one-third of the mercury that evaporated did so in the first eight hours after the breakage; the rest seeped out slowly over the remainder of the study period.

Taking this into consideration that would result in 6% to 13% of the mercury being released in the first 8 hours, or 0.18mg to 0.39mg of mercury. Assuming your in a room with a volume of 25m3 (similar to a medium bedroom), this would average 0.0072mg/m3 to 0.0156mg/m3. This is equivalent to 7.2µg/m3 or 15.6µg/m3 over 8 hours. In comparison a single amalgam filling with an , average surface area of 0.4 cm2 has been estimated to release as much as 15µg mercury/day, primarily , through mechanical wear and evaporation, but also through dissolution into saliva (Lorscheider et al. 1995). For the average individual with eight occlusal , amalgam fillings, 120µg of mercury could be released daily into the mouth, and a portion of that , swallowed or inhaled (Lorscheider et al. 1995). Both Canada and WHO consider dental amalgam to be the single largest source of mercury exposure for the general public.

Something that may astound you is that the levels of mercury in a dentists surgery is up to 69µg/m3. Up to 9 times the mercury from breaking a bulb in your medium sized bedroom. Considering this you are likely to be subjecting yourself to more mercury sitting in the dentists than from breaking a CFL. Not that I am trying to put you off going to the dentist of course. There are mercury free dentists up and down the country.

As a light hearted way to end this I thought I would highlight the 102 year old ex-dentist that has emigrate to New Zealand, a story published on the same day as the Low Energy Bulbs Disposal Warning, by the BBC. Surely he should be as "Mad as a Hatter"!


If you do break a CFL bulb then follow this advice;

1. Do not allow children or pregnant women to enter the affected area
2. Open windows and allow air to circulate to the affected area
3. First sweep up all of the glass fragments and phosphor powder (do not vacuum)
4. Then place in a plastic bag
5. Wipe the area with a damp paper towel to pick up stray shards of glass or fine particles
6. Place the used towel in the plastic bag as well, and seal
7. For proper disposal of a broken CFL bulb, contact your local authority for a community household hazardous waste collection

For more information and discussion on CFLs, how to recycle, and the mercury within visit the CFL Mercury Myths