Hi Miss_Vicki,

Most makeup primers are anhydrous (meaning they don't contain water), so they can last for up to a year as long as you keep your hands and fingers out of it.

OK thanks for the info :)

I've heard a year is a rule of thumb for primers and foundations.  Personally, I try to get stuff that has expirations dates on them.  I'm really bad about using up stuff quickly enough, cause I don't use the same stuff everyday.

My Revlon foundation has a symbol of a open jar and "24" next to it.  I found out this means it's good for 24 months after opening, but I try to use it up by one year.  I use a sponge to keep my fingers from touching it, after washing my hands and the sponge first.

Most beauty products do have little icons on the packaging saying how often to throw them away (in months). If it is a pump or squeeze tube, I'd say you could keep it for longer than a product with packaging that touches your skin (has a wand, or brush, etc).

I'd like to add my experience with the Revlon foundation I mentioned a couple of posts ago from 2 months back.  Apparently, I bought this when it was already past its prime.  I got it at Ralphs, and they probably don't have a high turnover on cosmetics like a drugstore. Who knows how long it's been sitting there?  I only got it there cause I had a store coupon I could use on anything, and the total for it ended up being less than half-price.

Anyway, I just recently used it up after opening it about a year ago.  The label has an icon on it that means, supposedly, good for 24 months after opening. I've had no trouble with it over the past year.  Looked and smelled okay. No skin irritation. I shook each time to be sure I got all the heavy residue on the bottom.

As a habit, I rinse out containers before I recycle them, be it a food, drink, or cosmetic.  Since the foundation bottle is glass, it's recyclable.  Well, you'd think a couple of rinses, esp. shaking vigorously, would get the residue out! I even tried soaking it overnight.  Just out of curiousity, I tried dish detergent in the water, another time baking soda & vinegar which usually cleans off ANYTHING around the house.  I tell you, that old residue is sticking to all sides of the bottle like cement.  I thought maybe that was the COLOR of the bottle, until I started seeing tiny bits of it breaking up.  So far, I've been doing this over a week......and that foundation is REALLY clinging to the bottle....

UPDATE:  What did the trick was full-strength Mr. Clean.  10 minutes of soaking got rid of the old residue, but leaving it overnight really cleaned it out, 90% of it anyway!  Now I can see the clear glass it came in.....