Beauty Without Fuss

Monday 5 July 2010

Guest Post: Cosmetic sell by dates and other nonsense.

Today's post comes from the lovely Modesty Brown, I adore her blog, and she deserves to be so much better known, so please, go show her some love!


‘We wouldn’t hesitate to chuck out mouldy or bacteria-ridden food – and the same standards should apply to lotions we put on our skin.’

A few months ago I came across this article in the Mail Online. I have come across recommendations for discarding cosmetics before, but this particular article for some reason really got on my nerves. I suspect it was the spectacularly short shelf-lives prescribed for many of the products mentioned. As well as the rather alarmist slant (what was I expecting, it is the Daily Mail).

This is probably a good point to explain that I am actually a science nerd, specifically a skin microbiologist. I know quite a lot about the bacteria that live on your face (and have had a reasonable amount of experience with pharmaceutical companies). So, naturally I wanted to know if these recommendations were based on sound research or just a load of old flannel!

The bacteria living on your skin are there all the time, they don’t cause infection on your skin ordinarily so I don’t entirely understand the implication that bacteria will ‘breed’ in your make up and cause horrible infections like Impetigo. Unless of course you have been sharing your make up with someone that has open blisters? No, I thought not. Also, I’m not convinced that powdered make up like blusher and eyeshadows would make particularly good growth environments for bacteria.

With items such as mascara or lipgloss I agree there are good reasons to be cautious. Both mascara and lipgloss provide a good growth environment, it is moist, dark and pushing the wand/applicator back in drives air in to the tube.  Though having said all that make up does contain preservatives to prevent growth. With my background I was rather intrigued about what research had been done to investigate microbial contamination of make up. I also wondered if there was anything out there to explain the time frames for expiry.

Interestingly, I managed to find some research into contamination of mascara. In the study women were given a mascara to use daily for 3 months. Two different brands were tested, Avon and Maybelline. At the end of the study the mascara wands were tested for microbial contamination. Although their conclusions were that mascara should be discarded after 3 months, I wouldn’t necessarily agree with this based on their results.

Growth was discovered in 12% of the mascara’s but the numbers of bacteria were very small. I won’t bore you with exact figures but from personal experience I can assure you the level of contamination was very low. Also, of the bacteria they isolated, none of the species would cause an eye infection unless there was a scratch on the eye. They managed to grow bacteria from the unused control tubes as well, so some of the bacteria were already in the mascara tubes. Which suggests that contamination occurred during manufacture. Although the research made for interesting reading, for me, it wasn’t a terribly convincing argument that mascara is easily contaminated or poses a serious health risk. I was however horrified by this particular gem from the paper ‘Some will add water, and even saliva, to make their makeup last longer’. Who on Earth spits in their mascara to make it last longer?

I failed to find any research testing other kinds of make up for bacterial contamination. I found lots of articles stating eyeshadows, lipsticks etc., can become contaminated but no research or statistics to back it up. This leads me to think that these sorts of tests are being done by the cosmetics companies and I know they are rarely able (or willing) to share their results! I know that it is also the companies that set their own Period After Opening (PAO) dates, so of course the cynic in me thinks that the dates might well be a bit of a marketing ploy.

Now, I’m not going to advocate you ignore all the guidelines but I would like to suggest that you follow your own instincts before throwing away the contents of your make up bag! As long as you are not sharing your make up, keep your brushes clean and store your cosmetics in a cool, dry place, you can keep it safely for much longer than the expiry guides suggest. My other key advice is to trust your nose! If a product changes texture or starts to smell, bin it. Don’t ask me to describe the smell folks, just believe me when I say you’ll know!


  1. Thanks SO much for this post, I'd always wondered if the expiry dates were a ploy to get people to buy more products more often. This certainly makes me feel better about keeping my mascara past 3 months ;]

  2. I know I would say this but excellent post. Confirming exactly what I've always suspected. Thank you!

  3. Great post, I have suspected as much myself! And having read Ben Goldacre's Bad Science recently, have become overly suspicious of most scientific stories in the media!

  4. This post was SO interesting to read, thank you for doing all this research! I am very cautious about make-up and skin care ingredients and the only way for me to calm down is when it's backed up with science. I think, though, that organic cosmetic brands try to avoid putting a lot of preservatives into their products. Maybe it's a slightly different story with them.
    Have a great day xxx

  5. I'm so glad you enjoyed reading and it was informative. It was certainly very interesting to research.

    Sam, it's very interesting that you have touched upon the preservatives. Whilst I was doing this research, I came across mention of a more intelligent way to preserve cosmetics. It made use of ways to challenge the microbes rather than adding excessive amounts of preservatives. I hope to investigate this a bit more and write a blog post soon.

  6. Good post! I always read about different expiry dates for products - I wonder if it would vary brand to brand?

    'Who on Earth spits in their mascara to make it last longer?'

    My Mum and Aunty once PAID for a professional make over and the MUA spat on the mascara wand. I kid you not.

  7. good post! glad to know some others who also do not follow the sell-by date, and of course the 3-month mascara thing...

  8. A great post, I have kept mascara for 6 months with no issues and had always wondered about expiry dates.
    Spitting on mascara - eww.

    - Athena

  9. My dear, it would be SO great to get to know more on this issue!!
    I used to react massively to the preservatives in my contact lens solution - it took the doctors AGES to find out what it was!! Most drug store make-up products make me suffer once they reach my eye area! It is so sobering to know that the make-up industry puts all these chemicals into their formulations because it's the cheapest way for them to deal with important issues such as hygiene... yes, please let me know on what else you find out! cheers, Sam xx

  10. Thank you so much for this post. I've always thought that those expiration dates were a bit silly and random, and it's great to see someone having done some actual research into the matter.

  11. Fantastic post! I love Modesty Brown myself.

    I use the smell and visual test myself -- if it smells or looks bad, out it goes. Otherwise, I keep things for a long long time. I'm also a bit OCD though when it comes to my makeup -- no sharing, always cleaning brushes etc.

  12. I like your post.
    It's great info.

  13. I remember when they introduced the PAO symbols, it was said to be because they couldn't guarantee the stability of the products after that time - well if their factoring in people doing stupid things like spitting in there makeup then I guess not.....

    Never been one for going by the POA's unless it was as an excuse to get rid of something :)

    Great post.

  14. Great post, I think its easy to fall into the trap of believing what you read over and over again about when you "should" be throwing makeup away, so its good to hear from someone who actually has knowledge in that area x

  15. I've always had the feeling that the guidelines provided by manufacturers could be more like suggestions, really...but wasn't sure how to go about testing that, or even what questions to ask to test the validity.

    I will continue to go by appearance/smell/texture for mascara, eyeliner, and lipsticks. My loose-powder stuff...that's going to last until it sits up and asks me why I won't let it out of the storage area. (Actually, I am keeping an eyeball toward a few of the "moist"-looking things like my few MAC pigments and my BE "high-shine" colors. I'm not quite so worried about the rest.)

    Thank you for a very informative post with some good, logical, counterbalancing information!!

  16. Excellent post - I really hope people will read this and take notice!

    I can't stand when I hear that people throw away mascara after 3 months because of the PAO. Mascara rarely causes eye infections, I know I have never had one!

    When I did my little post/rant about supposed out of date mascara I actually spoke to an Optometrist and she wasn't really concerned about mascara's containing harmful germs and whatnot just you shouldn't share mascara or put it in extreme hot or cold areas!

    It is kind of common sense...but I can see why PAO's and articles like the one in the Daily Mail can sway people to not use there common sense!

    Anyways I need to stop now.... as I said before, really great post :) xx

  17. Absolutely fantastic post!

    I'm a microbiologist myself so this made me all kinds of happy. I've never gone by the "throw away" dates personally. I know there's going to be very little of anything growing in powder products and besides, with my massive collection, it would cost me a fortune to replace all my eye shadows every two years.

    Everything creamy I keep until it smells different or has changed consistancy.

    Interesting point about the bacteria in mascara, what was it that grew (I'm guessing Staph epidermis or aureus?)? I'm the only one who uses my mascara anyway so I keep it longer than three months.

  18. I really need to come back and reply to all of your comments. I have my parents here and I've not seen them for 6 months so I've been busy catching up. I'm absolutely thrilled by all your comments and I promise I will come and respond to you all :).

    I was so pleased to see your comment Sirvinya that I just couldn't wait to answer your question! The found S. epidermidis and Streptococcus spp. The Strep was found in the control tubes though so I'm sure this was contamination that occurred during manufacture. They failed to isolate any S. aureus. As they didn't isolate anything pathogenic I didn't understand the conclusion. It wasn't a quantitative study but the numbers they were reporting were so low. If you want me to send you the link to the paper for a kick skim let me know. Always lovely to speak to a fellow microbiologist :)

    Jane x

  19. @Ben – Thank you!

    @Sparklz and Shine – lol, the dates are quite helpful if you need an excuse to get rid!

    @Replica – Thank you. It’s true isn’t it, if you hear something enough times it almost becomes ingrained as fact.

    @LiAnn – Thank you. I think using your own common sense and judgement is always the best way to go. If you’re using good practice powdered items will last so much longer than the suggested dates.

    @Makeup Savvy – I’m really pleased you enjoyed it, it means a lot. Certainly I didn’t find any data on the frequency of infections caused by mascara. I agree with Optometrist too, the major concern is people not using good hygienic practise, like spitting on mascara! ;)

    @Sirvinya – as I said before, it’s great you enjoyed reading. Lovely to have another microbiologist take on it. Having grown bacteria and yeast it’s difficult to see what could actually thrive in powder isn’t it?

    Once again, I want to say a big thank you for the terrific feedback. A huge thanks too to Get Lippie for giving me the opportunity to guest post. xx

  20. @SilhouetteScreams – I believe that some mascaras have a PAO date of 6 months so 3 months is definitely extreme.

    @Charlie – thank you my lovely.

    @TheBeautyEdit – I bet I’d really enjoy that book.

    @Beauty’s Bad Habit – I think some of the PAO labels are different for the same products but produced by different companies. In theory I suppose it should reflect the results of preservative and safety testing. I really did struggle to find data though.

    I cannot imagine their faces the when the mua did that!! My Mum said something interesting with regards to this. Apparently it was common practise to use saliva to mix up block mascara to load on to the brush. I suppose some people never lost the habit! It still makes my stomach turn thinking about it all the same!

    @Jennifer – it’s always good to know you’re not on your own.

    @Athena – Yes, eww indeed!

    @Sam – I promise I will get on and write that post very soon.

    @Shelby – The dates do seem so short. I really wanted to know what they were based for myself as well as everyone else. I’m definitely sticking with my own judgement on when an item is for the bin!

    @Lipstick Rules – Thank you, you are so lovely! I think the OCD isn’t a bad thing, it’s certainly the best way to preserve the life of your make up.

  21. Wow, you really answered EVERY single one of us!! That alone is great work :) Thanks, hon xx


Thanks, I love hearing from you!

© Get Lippie | All rights reserved.
Blogger Template by pipdig