"I still own a lipstick I bought in the '90s, is it going to kill me?"

Image: It might be time to step away from that lip glass you bought in 1998. (Columbia/Sony Pictures)

Amazing makeup products can be hard to part with, but some of us take our devotion to extreme and probably hygiene-compromising lengths.

While most beauty products are clearly labelled with the number of months they should be kept, a number of ladies at The Glow HQ are still using items that passed their prime months, years and, ahem… decades ago.

“I have a lipstick that I have had since the ’90s. That’s probably a mistake. It’s kind of gritty on my lips but that’s, like, exfoliating,” one resident hoarder admitted.

“I am still using a Sportsgirl creme bronzing stick my mum bought me circa-2003. It’s such a nice rose gold colour, I can’t part with it,” another* said.

Others simply refuse to chuck out the five-year-old eyeshadows and three-year-old mascaras living in their cupboards, while one staffer confessed to owning “a whole stack” of her mum’s lipsticks from 20 years ago — along with the lip glass she wore to her formal in 2001. Oh, the memories.

Watch: Yes, you should also be cleaning your brushes and sponges. Here’s how it’s done. (Post continues after video.)

Whatever your reasons — “It’s sentimental!” “It’s been discontinued!” “It’s Chanel!” “It’s probably good for my immune system!” — we’re not here to judge you. We’re all here together in the same glass house.

However, it would be remiss of us not to mention that ‘use within’ recommendations exist for a reason, and that reason is your health and hygiene.

Just as it’s not wise to eat food that’s gone off, your expired makeup might be exposing your lips, face and eyes to bacteria and possible infection — particularly if you’re applying it directly from the container. Beauty is pain, but conjunctivitis is no fun for anyone.

Generally speaking — it differs from one product to the next — this is how long you should be holding onto those lip, eye and face prods you love. Whether you abide by these guidelines is entirely up to you.

Lipstick and liner

You get just one precious year with your lipstick. All the more reason not to save that lovely Dior red just for rainy days.

Lip gloss

One to two years. (Post continues after gallery.)

Mascara

Three to six months. Yeah, months. And you should be replacing your eyeliner every three months.

Liquid foundation

Two years, although it's probably best to use it well within that timeframe. You'll know it's time to go when the formula starts to separate (and possibly smell odd).

Mineral foundation

Three years. These powder formulations give you a bit more time, thanks to their lack of water content — so do your darndest not to get them wet. (Post continues after gallery.)

Concealer

You'll typically get one year out of a liquid concealer, and two from a stick or powder version.

Blush

Two years, if it's a powder, and one if it's a cream.

Eyeshadow

Ditto blush.

Watch: We had a play with the latest Urban Decay eye palette. It definitely wasn't expired, don't worry. (Post continues after video.)

Face powder

Two years.

Brow pencils

One year.

Is there a beauty product you can't bring yourself to chuck out?

*OK, that one was me. No shame.