Each season, I take the time to go through my make up bag and see what stays and what goes. A helpful tip, with a silver sharpie, write down the date on the make up item to help you remember when it was first used.
Ideally, you want to make sure your make up is stored in a clean bag and that your brushes are protected in a separate bag from touching items that may touch your sink, counter or whatever surface they may touch. This reduces spread of bacteria to brushes and then your face.
Examining what's good and what needs to be tossed is easy if you follow the steps in which you normally take when applying your make up.
Primer sprays or pumps/tubes tend to come with there own expiration dates but if not, check your opened date. If its over a two years old, toss.
For foundations, check the ingredients as a water-based foundation will last up to 12 months, oil-based will last up to 18 months. You may find you need two different shades of foundation each year: One for summer when your skin is naturally darker and one for winter when you're lighter. I recommend a tube or pump foundation to minimize contamination to product. Apply with a new foundation sponge each use.
Concealer can last up to 12 months. But I toss mine out after 6-8 months. Concealers are generally used around the eyes because of this, I toss sooner. As the eyes pose risk of bacterial infections. I don't know about you but I avoid chances of catching pink eye.
With that said, same goes for eyeliner pencils or liquid, mascara and eye shadows. Always be extra careful with eye products because you can easily introduce bacteria to them. If you do get pink eye, toss all eye related make up and avoid using any new items until it is completely gone.
Pencil eye liners should be sharpened regularly and wiped with rubbing alcohol before and after each use. Do this and it could last up to 1 year. Otherwise, I would toss after 6 months to avoid bacteria that grows from the eyes to the product. Liquid liners 6 months.
Eyeshadows, will last up to 2 years if applied correctly. I use a clean brush and make sure to clean my brushes immediately after. This habit insures that your eye make up will stay fresh longer.
Mascara expires the fastest and can hold the most bacteria. Throw out after 4-6 months. Don't pump your mascara in and out, this pushes air into the case trapping it and drying it. As well as making a happy home for oxygen eating germs. This ruins it faster.
When it comes to the mouth, you have to be cautious with bacteria as well. Lip liners can last up to 3 years.
Lipsticks 1-2 years. However if it smells rancid, throw it out, it's spoiled. If its a shade you love you could refrigerate it to preserve it longer. However, that's not very practical. Same goes for glosses and lip balms.
So why be cautious? If you have had or suffer from herpes "cold soars" and have an outbreak, toss what you have used out. If not, you are more likely to develop a chronic condition. And no one wants that.
Brushes are generally recommended that you wash every 2-3 months in a mild detergent, dry bristles facing down. I say, wash after each use or at least once a week reducing the opportunity for bacteria to grow. Especially for those with oily skin and acne. Germs just love to eat up the oils and dead skin cells found on brushes.
Make up sponges, I recommend you buy the disposables. Toss after 2 uses.
This probabyly doesn't have to be said but please don't share your make up. Especially not your eye makeup, because that could only lead to trouble. And don't feel bad about tossing out old makeup. It only gives you the excuse to go out, try and buy more. Happy hunting!
I hope you found this helpful.
As always, Be Blessed, Be Healthy and Be Beautiful!