Why does laser toner have an expiry date?

July 17, 2007 5:58 PM

Why does laser toner have an expiry date? My laser toner cartridge finally ran "dry" after 8 years of use (same cartridge) and the replacement refill that I purchased has an expiry date which is listed as a little over year from now. I also believe that most new cartridges also have an expiry date but since mine lasted for so long, I don't understand the purpose of having an expiry date.
posted by DonM to computers & internet (8 comments total)

Is it an expiry date or an "End of Warranty" date?
posted by wsp at 6:03 PM on July 17, 2007

The box was marked "Use before XXXXXX"
posted by DonM at 6:38 PM on July 17, 2007

Expiry dates generally mean the retailer shouldn't sell it after that date not that it self-destructs on that date. So you take whatever is the typical amount of time it takes to use up the product and add it to the expiry date and then you have the last date that the manufacturer is certain it will still work well. The date at which it becomes more likely that it will fail than work comes a long time after that.
posted by winston at 6:39 PM on July 17, 2007

At least half the reason it's there is so stupid people will buy more toner.
posted by chrisamiller at 7:00 PM on July 17, 2007

Yeah, a lot of expiration dates have little meaning. My doctor just gave me samples of a medication that "expired" this past February, but she said it's still good for 3 more years.
posted by IndigoRain at 7:05 PM on July 17, 2007

Many printers (I don't know if yours is one of them) will reject printer cartridges after a certain date as forced obsolescence.

This could be the warning.
posted by unixrat at 9:36 PM on July 17, 2007

One other thing is that the stuff can absorb moisture and cake up - refills cans be particularly prone to this, due to a less-than-dry environment during filling and imperfect resealing. This can lead to problems ranging from spotty / poor printing to a mess of half-baked toner all over the inside of the printer.

Having said that, to a fair extent the dry ozone-y and vibrating environment inside a printer helps prevent this from happening. At work, we usually treated it as an "install by" date and had no problems even with refills - though we used cartridges at the rate of 1 every 6 ~ 12 months or so, not 1 every 8 years!
posted by Pinback at 10:11 PM on July 17, 2007

Usually, if the new cartridge is stored in a properly evacuated and sealed bag, it's got a shelf life of a really long time. Once that bag's open, it's subject to ambient moisture and pollutants, and the clock begins ticking. Like Pinback says, it'll eventually cake up and print badly.

The toner in a printer in an arid environment (continuous air conditioning, for example) will, all else being equal, last longer than what's in the printer in an unventilated basement.

Chipped printer cartridges with compulsory expiration dates are a relatively new phenomenon. It's improbable your over-eight year old printer is subject to that.
posted by ardgedee at 4:12 AM on July 18, 2007