PAO: A Guide to Cosmetics shelf-Life
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Different surveys show that people keep cosmetic and skincare products up to 6 years after the expiration date. That can represent a problem for your skin. How long do you keep them?
We need to keep a hygienic routine with our beauty products and tools but it is very important to keep in mind the expiration date of the products and the Period After Opening (PAO), the maximum time we can keep them after opening the product for the first time. To know more about that and how to find out the PAO read my post in Labels in Cosmetics.
Why cosmetics have PAO?
When you open a cosmetic for the first time, the product becomes in contact with the air in the atmosphere. It will be also in contact with our fingers, makeup brushes and our skin and that can help microbial growth. Obviously, different products have different PAO. Product with a low amount of water or without water, high quantities of alcohol or extreme pH have longer PAO as these conditions prevent microbial growth. Natural cosmetic products have a short PAO because they normally don’t have preservatives as ingredients.
Some products don’t have PAO. In these products, there is no risk of microbial growth or physical-chemical degradation. We can find in this group spray products where the product is never in contact with air or a single dose as you open a dose per application.
Something important is that you should know the difference between Period After Opening and Expire Date. The expire date is the date from the product may be in bad conditions provided you didn’t open it while Period After Opening or PAO is the time you can use the product after open it, independently of the expiration date.
What happens after the expiration date or PAO?
There are different possibilities. Sometimes nothing happens when you apply the product to your skin, there is no adverse reaction but any benefit neither. Other times you can fell some sort of itchiness or discomfort which goes after some time. In the worst case, you can have an allergic reaction or adverse reaction when you apply the expired product. The reason is that the ingredients in the cosmetic suffer degradation to some extent and because of that, their activity is reduced and degradation products can appear. It is possible that because of the degradation irritant particles appear, which can produce an adverse reaction in your skin, as redness, itchiness, irritation, allergies. That is especially important in sun protectors. If the product is expired, it may not protect you against sun radiation.
Another important fact we need to think about is the possibility of infection produced for misuse of the cosmetics, for example, if you leave it open in the bath or you don’t clean the lids bacteria and fungi can grow in the cosmetic and produce infection when you apply. That is especially important in the case of eye products, as an expired product can produce conjunctivitis in the better of the cases.
How do you know your cosmetic is gone bad?
You need to check the presence of lumps, changes in colour, texture or smell. In the case of creams and foundations when a product goes bad phase separation can appear. That means that you will see two layers, one corresponding to water-soluble components and the other to oil-soluble ingredients. Normally, cosmetic products last between 3 months to 3 years, depending on the cosmetic. It is important to be careful with that and check the products regularly and before application. It is a good idea to write down the date when you bought and opened it, to keep control of that.
How can we extend the life of our cosmetics?
There is simple guidance you should follow to be sure you are applying products with no risk to your skin.
- Always wash your hands before applying any product. You will avoid bacteria transmission mainly in products where you should introduce your hand or fingers to apply, as in most of the creams. If possible apply with a spatula and wash it after each use.
- Keep cosmetics closed and far from sunlight. If you don’t do that, water contained in the product will evaporate and the product will oxidise and become ineffective.
- Avoid high Temperatures. Don’t keep them long in the car or kitchen, where the temperature can be very high.
- Keep your cosmetics, brushes and applicators clean. These products and tools can contain millions of bacteria and that can produce allergic reactions and infections. Wash brushes and sponges after every use, with gentle soap and make a deep cleaning every week.
- Do not share your cosmetics. Cosmetics can contain bacteria that can be transferred from one person to another if shared.
- If you suffer any eye or lip infection, bin the products used. Your products may be infected if you used them while having an eye or lip infection. That infection can re-appear if you use a contaminated cosmetic.
Which is the shelf life of my products?
To answer that question, you should look at the PAO of each of the product you use. I have a permanent marker in my bathroom and I write down the date I open each product. You can do that at the bottom of the bottle if you don’t want to make it visible. At the end of each every term I check the PAO of each product and dispose of the expired ones.
However, it is important to have an idea about the products’ shelf life, mainly when we are planning to buy more products. We need to keep in mind the PAO as sometimes it is not possible to use them and we are wasting products. For example, mascara’s shelf life is a maximum of 6 months, so you should keep in mind how much do you use it before having too many mascaras open at the same time, which most probably will finish in the bin.
To make your life easier, I made a list of the most common cosmetics and the corresponding PAO. It is only for information and doesn’t pretend to be exhaustive. Always check the PAO and expiration date in the pack and check how the product is before applying.
< 3 months
- Makeup Sponges
3 to 6 months
- Liquid Eye Liner
- Cream Eyeshadow
6 to 12 months
- Liquid Foundation and Concealer
- Gel Eyeliner
- Cream Blush, bronzer and highlighter
- Eye cream
1 to 2 years
- Face Wash
- Face Mask in a tube (not the sheet masks)
- Shampoo, Conditioner and Shower Gel
- Nail Polish
> 3 years
- Powder makeup (eyeshadow, blush, bronzer, highlighter, setting powder, etc.)
- Lipsticks and Lipglosses
- Eye and Lip Pencil
- Spray products (deodorants, face mists, fixing spray, etc.)
- Single-dose products (capsules, tissue masks, sample products, etc.)
Bear in mind that some of the links in this post are affiliate links and if you go through them to make a purchase I will earn a commission. Keep in mind that I link these companies and their products because of their quality and not because of the commission I receive from your purchases. The decision is yours, and whether or not you decide to buy something is completely up to you.