Technology Marketing from the Front Line

Technology Marketing from the Front Line

Link

Are CFL light bulbs practical and safe?

August 23, 2010

A few days ago I wrote an off-topic post complaining “green” builders are not using CFL lights. I got a number of responses, including one from a homebuilder association that defines the TX Green certification explaining CFLs have mercury in them which creates a number of concerns: environmental, breakage and disposal, in addition to additional cost. When I got these responses I felt like and idiot for writing about the issue if there is a good reason why CFLs are not used. But then, I spent some time doing research and arrived at a different conclusion. There are easy ways to deal with every one of the potential issues.

First, the good news. Incandescent bulbs are being banned in the EU.

Why is this important? For our a small subdivision like the one where we live with 200 Homes, replacing 70 light bulbs per home (the number I replaced) would mean 14,000 CFL light bulbs replace the same number of incandescent bulbs, resulting in over half a million dollar in electricity cost savings, preventing over 1.5 million pounds of coal from burning and a reduction in 6.3 million pounds of greenhouse gases PER YEAR.

Now let’s look at the key concerns from the builder:

1. Mercury in CFLs

Manufacturer investments in technology over the last two decades have reduced the amount of mercury used in lamps by nearly 95%. The National Electrical Manufacturers Association (nema.org) has established a maximum of 5 mgs of Mercury per light bulb, but many of the latest modern have as little as 1.23 milligrams. According to the EPA, a 13 watt CFL over 8,000 hours of use could result in 1.8 mg of Mercury emissions versus 5.8 mgs for an incandescent. The CFL results inalmost three times less mercury emitted to the environment. “CFLs result in less mercury in the environment compared to traditional light bulbs“ (5) EPA adds: “Because CFLs also help to reduce greenhouse gasses, other pollutants associated with electricity production, and landfill waste (because the bulbs last longer), they are clearly the environmental winner when compared to traditional incandescent light bulbs.”

2. Dealing with broken CFLs.

If a CFL containing the maximum allowable, 5 mg of mercury, breaks in the average bedroom with a volume of about 25 cubic meters, assuming all the mercury vaporizes immediately (an unlikely occurrence), would result in an airborne mercury concentration of 0.2 mg/m3. This concentration will decrease with time, as air in the room leaves and is replaced by air from outside or from a different room, likely approaching zero after about an hour or so. This level and duration of mercury exposure is not likely to be dangerous, as it is lower than the US Occupational Safety and Health Administration (OSHA) standard of 0.05 mg/m3 of metallic mercury vapor averaged over eight hours. (3)