No. 104 - Miljøstyrelsen

22
2.3 Survey of types of mercury compounds in fluorescent lamps
Three manufacturers/importers have told which mercury compounds are
added to different compact fluorescent lamps and straight fluorescent lamps.
The mercury is used in the fluorescent lamps either in the form of a HgFe
compound, in the form of amalgam or in the form of metallic mercury.
According to the manufacturers/importers bismuth (Bi), tin (Sn), indium
(In), silver (Ag), lead (Pb) and zinc (Zn) are found in different combinations
in the amalgams used. Following combinations have been reported:
� ZnSnHg
� BiInHg
� BiInPbHg
� BiSnPbHg
� BiInSnAgHg
� BiInSnPbHg
Based on information from manufacturers/importers it is not possible to find a
correlation between type of fluorescent lamp and type of mercury compound
used.
According to Groth (2008) consumers are better protected against exposure
to mercury in fluorescent lamps using encapsulation of mercury (in the form
of tablets or as amalgam) compared with liquid mercury in the fluorescent
lamps – due to the fact that the mercury is bound.
Compact fluorescent lamps with an extra casing also give better protection of
the consumer since in some cases only the outer casing breaks during
accidents in homes.
2.4 Future developments
As described in Snijkers-Hendrickx et al. (2007) manufacturers are working
to reduce quantities of mercury in compact fluorescent lamps and straight
fluorescent lamps, among other things through work with/research in
technologies for dosage of mercury to the lamp, the materials the lamp are
made of and the use of different additives. All these issues have an impact on
the quantity of mercury needed in a fluorescent lamp.
Research is also made in how to reduce releases of mercury when a
fluorescent lamp breaks. Lee et al. (2009) has shown that the use of a nanoselenium
barrier can reduce evaporation of mercury.
The purpose of this project has merely been to focus on the risk arising from
mercury-containing compact fluorescent lamps/straight fluorescent lamps
breaking in homes. Therefore no further details on technological
developments in this field are given here.
2.5 Summary
A brief survey of the market has been made by contacting
manufacturers/importers of compact fluorescent lamps and straight
fluorescent lamps, and by conducting searches on the internet.