I have a growing awareness of my problem-skin and so especially after my big cosmetics sort out last month, I've been increasingly conscious of the shelf life of my products.
I have started labelling all of my cosmetics with the date that they were opened. It's so easy and quick to scribble 4 digits onto a little sticker.
The majority of products are now marked with an icon indicating how long the product should be used for once opened. While there are guidelines on how long you should keep various cosmetics, this will vary depending on the ingredients and relies heavily on common sense. If the product has dried out, changed texture or colour or smells strange, get rid of it. Avoid sharing make up too as this multiplies the chance of contamination and potential infection.
Information of the average shelf life of different cosmetics can be fairly easily found online but even so, I have been guilty of ignoring best before dates on occasion. I think the most important pieces of information to share are the side effects of using out of date products.
Average shelf life: 3-4 months
Using out of date mascara can cause bacterial infections of the eye which can be highly contagious and will most likely cause unattractive redness. Equally, if you have suffered from an eye infection, discard any eye products which you have been using.
Average shelf life: 1-2 years
Using out of date lipstick can cause allergies and infections or at least may dry out the lips leaving them sore and chapped.
Average shelf life: 1 year
Bear in mind that you are probably using a concealer to cover existing skin imperfections such as blemishes possibly caused by bacteria in the first place. Especially when using a concealer applied with a 'wand' be careful not to introduce bacteria into the contained product.
Allergies can even be triggered by using out of date products.
It will help to use makeup applicators where possible to apply your products but make sure that these are washed regularly as unclean brushes and sponges can harbour just as many nasties! I always try to opt for skincare products which are in a tube or bottle as opposed to a tub as every time that you open a tub you are exposing a larger amount of the product to the air which will cause it to breakdown quicker. Dipping fingers in and out of pots/tubs/jars is also massively increasing the risk of contamination.
I don't have a huge abundance of makeup and tend to stick to a relatively small selection of favourites but even so, I rarely use up lip and eye colours before the expiry date and it can get very expensive to keep repurchasing. I just have to keep reminding myself that it's worth it to avoid irritating my skin further.