I learned something new today.

Most beauty products, like lipstick, moisturizer and mascara, have a little symbol on the packaging somewhere that tells how long the product can be used after opening before it’s no longer “fresh” or suitable for use.

It’s that little jar with its lid off and a number inside or next to it. There’s a Wikipedia entry for it if you still don’t know what I mean.

I’d always wondered what that icon meant. Now, I know it’s called a PAO symbol. PAO stands for “period after opening.”

So I’ve been sitting at my desk, looking at the handful of products I have with me today and finding out what the “expiration” dates for them are. For example, my NARS blush, eyeshadow and lipgloss are good for two full years after opening them. My Diorshow mascara is good for six months after opening it. My Korres lipstick — one year.

I learned about this through Twitter, where I’m following LumeneGal, who tweets about Lumene products (so much love) and other general beauty topics. From her, I came across an article on Daily Makeover about this subject. Since I didn’t know what that symbol meant until today, I figured it made a good thing to blog about since there’s isn’t a whole lot about makeup and the like that I am not at least somewhat familiar with. The more you know, right?

Now when I get home I’m going to be looking at all my stuff (quite a task) to see what’s what in terms of when things will no longer be recommended for use. You should do the same! It’s time for spring cleaning, after all!