The shelf life of LaserWriter toner cartridges is approximately two years. The label on the end of each toner cartridge states the expiration date:
"Use Before 19XX" or "Use Before 20XX."
The two-year shelf life of the cartridge is designed to ensure that the print quality will meet Apple's specifications for the expected life of the cartridge. In other words, the cartridge can be stored under the environmental conditions specified on its box, and meet print quality specifications for the rated life of the cartridge.
Since all of Apple's toner cartridges ship in airtight-, light-proof bags, they are protected from light, humidity, and chemicals (such as ammonia-based cleaners) that could shorten the life of the cartridge. The one environmental variable that cannot be controlled by the packaging is storage temperature. To ensure that a cartridge will function correctly after storage, Apple recommends that you keep LaserWriter cartridges at room temperature, about 25 degrees Celcius.
Over time, toner tends to settle in the toner bin and may form clumps. These clumps may affect print quality if they are not broken up prior to use. If you plan to store cartridges beyond the normal shelf life, you should occasionally rock the toner cartridges back and forth to help redistribute the toner and break up any clumps that may have formed. There is no recommended guideline for this, but every six months should be sufficient. Apple cannot guarantee that print quality will meet Apple specifications if cartridges are stored beyond their normal shelf life, however.
Color LaserWriter Toner Cartridge Shelf Life
The shelf life of Apple's Color LaserWriter models (12/600 PS and 12/660 PS) toner cartridge is also two years. There is a date code printed on each cartridge's box that consists of six alphanumeric characters. The first character indicates the last digit of the year, and the second character provides the month that the cartridge was produced. The month date codes are as follows:
A = January
B = February
C = March
D = April
E = May
F = June
G = July
H = August
I = September
J = October
K = November
L = December
Toner Life
For information on how long toner cartridges last once they are installed in a LaserWriter printer, see the following:
Tech Info Library Article 18014: "
LaserWriter: Toner Cartridge Life"