Have you ever noticed your laser printer running out of toner—usually the night before a big project was due—and realized that you didn’t have a replacement toner cartridge on hand? Did you try to extend the toner cartridge by taking it out of the printer, shaking it, and putting it back in?
Printer manuals and those instructions which come with toner cartridges say not to do this. But is that just because they want to sell you more toner, or is there an actual reason you shouldn’t shake toner cartridges?
The answer is: it depends.
When It’s (Mostly) Safe To Shake Toner Cartridges
Most home and small office printers use a combination toner cartridge. The cartridge holds more than just toner—it also contains the imaging drum and developer. The imaging drum creates a static electric version of your image and the developer statically charges tiny amounts of your toner and applies it to the charged parts of the drum. Then the imaging drum rolls over a sheet a paper, transferring the image onto it.
When you replace your combination toner cartridge, you also replace the imaging drum and the developer. This is important if you plan to shake your toner cartridge because using the developer when you’re low on toner can damage it—but you don’t really need to worry about damage if you’re going to replace it in a few days anyway when you get your new toner cartridge.
Of course, if you’ve ever shaken a toner cartridge, you probably know about the other risk—toner might leak out of the cartridge. Toner powder is extremely fine—individual grains can be from 12 to 5 micrometers (microns) in diameter, making them act like dust. They can get on your clothes, in your eyes, or in your lungs if you inhale them.
- Toner on your clothes should be washed off with a cold rinse cycle. Toner is designed to be permanently melted into paper, so you definitely want to avoid exposing your clothes to anything hot—like the summer sun—until you get the toner washed off.
- Toner in your eyes can quickly dry out your eyes, creating potential damage if left untreated. Common toner is just plastic or wax, so it isn’t toxic to the eye, but you should wash it out with cold water immediately to prevent dry eye damage.
- Toner in your lungs is a real problem. If you inhale toner, it’s a lot like inhaling dust, so you’ll start coughing immediately. The toner will stick to the inside surface of your lungs and inhibit the ability of your body to absorb oxygen. In the unlikely situation you inhale a major amount of toner, call 911 for immediate treatment. Toner is not toxic, so as long as you get over your initial bout of coughing, your body will remove the remainder from your lungs on its own. (But seek treatment if you have lingering concerns.)
To avoid problems without putting on safety glasses or otherwise looking like a dork, simply inhale, hold the toner away from you, turn your face in the other direction, shake, turn back slowly, and start breathing normally again once you verify that there’s no toner hanging in the air.
When It’s Never Safe To Shake Toner Cartridges
Large high-volume laser printers have a separate imaging drum and developer, and the toner cartridge is often just a transparent or translucent plastic bottle. You never want to shake the toner bottle.
Although shaking the toner bottle isn’t any less safe to your health than shaking a home or small office toner cartridge, if your printer runs out of toner because you tried extending the life of your bottle, your developer could break. High-volume laser printers have expensive developers, so it could cost you a few hundred dollars for a new developer and a few hundred dollars for the service tech to replace it. That’s too much cost for the benefit of printing an extra few dozen pages.
In short, with a normal home or office laser printer, shake safely. If your printer is the size of a desk or larger; don’t shake at all.