This Customer Support Ruling (CSR) describes the conditions under which Compact Fluorescent Lamps (CFL), also known as compact fluorescent light bulbs or compact fluorescent tubes, are mailable.
The Domestic Mail Manual (DMM) and Publication 52, Hazardous, Restricted and Perishable Mail, do not address the mailability of CFLs. However, with recent increases in the use of CFLs mailability questions have emerged.
CFLs are manufactured articles containing minute amounts of mercury. The amount of mercury in an average lamp does not approach the quantity that requires it to be transported as a hazardous material under Department of Transportation regulations.
CFLs are mailable when each article or apparatus contains 100 milligrams (mg) (0.0035 ounce) or less of mercury and each mailpiece contains no more than 1 gram (g) (0.035 ounce) of mercury. Lamps are to be separated and cushioned to prevent movement and breakage and must be enclosed inside a rigid outer packaging. The package must be marked, "Compact Fluorescent Lamps."