Rubber droppers BAD to keep in flavor bottles!

The FAQ on the TFA site here:

“it is not a good idea at all to store the flavors with the plastic eyedropper caps on the bottles. The rubber that’s used with the eyedropper’s is extremely soft and interacts
with a great many materials. If you try to store your flavors with these rubber dropper caps attached you will most likely ruin both the caps and the flavors. i hope this helps, linda”

Since I am measuring in weight, I’ve seen it suggested that one should try to buy flavors in glass bottles with EYEDROPPER caps, or transfer the flavors to them. This to make mixing quick and easy, with minimum cleanup, less to wash as each dropper would stay in their own individual flavor bottle, no cross contamination.

Sounded very efficient until I read that part of the FAQ. Wonder if that would also pertain to all the other possible juice ingredients as well. Any thoughts?


That’s what I’ve read before as well. I’ve had 2 go " bad " in the last couple years…and probably not from the rubber dropper just expired. I have plenty rubber dropper bottles w/ flavoring and pure extract none have been phased by it.

I have several with these droppers right in the vial.

And several with these dropper right in the pure extract

I also steep & store in glass bottles w/ droppers so I would take what you read w/ a grain of salt.


I use plastic bottles with the little spout tops and caps, they seem fine, they are easy to dispense into even the smallest of bottles (10ml).

I know plastics can leach into liquids over long periods of time and if you store your flavors near to any chemicals that they can also penetrate into your flavors.

Is this the same with e liquids then, most premium e liquids use those ?

I have experienced the issue of the “rubber taste” being tranfered to the flavoring due to storing flavors with the black rubber eyedropper capping the bottle for long periods of time. About 20 or so (15ml) bottles of flavoring had to be dumped down the drain because of this issue. :rage: Perhaps it happens only with certain flavors; I didn’t make a list of which flavors I dumped, but it was pretty much my whole stash of TFA flavors which had been stored in that fashion. Mentally, once I tasted one of the flavors which had been tainted, I couldn’t NOT taste it in any of the other flavors.

Since then, I started storing all of my flavors in the typical plastic flavor dropper bottles which come from most flavor vendors.

Live and learn! :smirk:


Maybe the flavors that are noted as being “tank crackers” are the ones that perhaps react with the black rubber droppers? :thinking:


Thanks for the confirmation, I’m sure you are aware, it’s recommended to store the flavors in glass bottles. I guess if you use them quickly enough it’s not a big deal. I’m expecting mine will sit longer, so I’d prefer to transfer to glass and use separate droppers or syringes, though that creates more things to wash afterwards. Thanks!

Probably I have in front of me Boston cream pie Cap that just basically died on me I used it a couple months ago and today I smell nothing. Guna toss it and get a new one. It probably is 2 years old come to think of it.


I think a small bottle of ejuice would not last long enough for any issues to arise.

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Agree with this statement, but… I try to buy everything in PET bottles with dropper tops and only in quantities that I can use up in 6-9 months. Haven’t had anything go bad in that time period yet. If I was storing longer term I’d probably stick to glass though.


doesnt medicne flower use rubber plunger for the dropper at least the ones i have do and i havent noticed anything and would think for the price they would be careful what they use


Several years back I had a 4ml bottle of TFA Orange with a medicine dropper top (cute lil thing it was). It sat for about a year before I tried to unscrew the cap, and it was stuck fast… finally got it off, and found that the rubber flange inside which sealed against the bottle’s mouth had turned into a sticky goo.

(the bottle didn’t come with the rubber bulb dropper; I added that myself)


That was one of the links I posted up on my statement…I’m thinking it has something to do w/ certain flavors that cause this.


I quit doing it a while back because the old stuff got stuck like it became part of the bottle and that did not seem good to me.

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I even read in various places that the soft rubber in the dropper style caps is not as airtight as let’s say a polycone cap on a glass bottle which means flavor molecules can escape. None of this is a huge deal if mix a lot and go through stock quickly. But for longer term storage I won’t be leaving dropper caps on my flavor bottles.