When I see fire extinguishers these days they seem to have some form of the yellow beaded tie as shown in this photo.
What purpose does this serve? It looks to me like it prevents the pin from pulling out. Hardly something you'd want in a fire. I've never had to use a fire extinguisher in real life, so please forgive my ignorance. Shouldn't the yellow tie be cut off?
The plastic ties are a tamper evident device, which lets you know if the fire extinguisher has been used. It also helps to prevent the pin from accidentally becoming dislodged, and potentially lost. They have a very low breaking strength, and can easily be broken by twisting (or pulling, but more difficult) the pin from the extinguisher.
I believe it's there to indicate that the pin has never been removed... to separate a factory new extinguisher from another.
I have removed the plastic tie from all the extinguishers in my home.
I found this, as I was wondering myself, and didn't know if I should keep it on or take it off, if I did would I lose the pin, if I didn't, would I be sorry in the event of an emergency.
http://www.supplyplaza.com/pull-tite-fire-extinguisher-seals-blank-p-649-l-en.html
Our fire extinguisher seals are tamper evident seals that allow you to tell at a glance if the seal has been compromised, yet are easy to break in an emergency. Standard pull-tite seals are a common safety feature for use on fire extinguishers so you know if the extinguisher has been used – don't take the chance that someone has tampered with the fire extinguisher and exhausted it, leaving it empty in the event of an emergency.
This polypropylene fire extinguisher security seal with has an average break strength of 13.5 lbs and 9.5" in overall length. Usable strap length is 7" and the diameter is 2.6 mm (0.1"). The flag is 0.8" by 1.3". Custom printing is available on all fire extinguisher seals with fast turnaround: print names, numbers or custom logos on the seal with no minimum quantity.
Another possibility, if this extinguisher's tag has a number or date (or if the tag is a form of color-coding), is that this may be used to indicate when the extinguisher was last inspected as part of a regular inspection and maintenance plan. This is typically performed annually, beginning with the date of installation.
More of a FYI but there are alternatives as well, some companies are switching their residential lines to use plastic pull pins that has a smaller resistance to pull out that it sounds like some people would prefer. Personally it was just the one I happened to pick up a few years ago so I have one at my house.
Here's some example photos of the Kidde FA110
I needed something more than a comment to post an image.
As others have said, it is a tamper indicator. The reason fire extinguishers have tamper indicators is that they must be recharged after each use:
You'll find this sort of warning in just about any fire extinguisher manual. Once a fire extinguisher is partially discharged, it will lose pressure over time:
Since not everyone reads the manuals, they can't be expected to know this. The pressure gauge is not necessarily a reliable indicator of whether or not the unit has been discharged. The tamper indicator will tell you whether or not your extinguisher needs to be tested or recharged.
The ties are there to make sure that the pin is harder to pull out. When tanks are filled the pins are put into place and then the ties are put on so that the pins don't bounce or wiggle out.
You get them with the ties in place because they don't want pins coming out during shipping or whatever.
You see them on walls and under cabinets "ready to use" with the ties because the people putting them up there are too ignorant to think about the ties or they have had people "accidently" play with them and want to make this harder.
