For as long as I’ve been interested in skincare I’ve heard that skincare companies are putting creams and other products in jars despite the risk of fingers transferring germs into the cream, where they presumably multiply and cause contamination, only to be transferred back to one’s skin in the future. Reviews of creams often dock points for jar packaging and/or the lack of a spatula to extract the cream without sticking one’s germ-filled fingers into it. Plenty of skincare fans have wondered if one spatula is enough, sometimes investing in multiple disposable spatulas to protect their creams.
I was unsure of the truth. On one hand, yes, even clean fingers aren’t totally sterile and could transfer bacteria and other contaminants to a jarred product. At the same time, if we all had colonies of bacteria, fungus, and/or mold living and multiplying in our skincare products I feel like we would see the horrifying results on our faces frequently.
The tipping point for me was an article on the growth of Korean beauty worldwide in which one corporate buyer was quoted as saying that when s/he asked kbeauty reps if their products have certain unpopular preservatives they responded yes–they had taken them out before, but the results had led to a lot of skin issues for users. This made me think that the companies liable for producing shelf-stable products…might actually know how to produce shelf-stable and even finger-use-stable products. I began to wonder if the concern about jar packaging was legitimate or if it was a tale often told but never proven.
An interview by Kerry of Skin&Tonics with cosmetic chemist Perry Romanowski included a question about whether jar packaging is safe. Romanowski answered that jar packaging is “perfectly safe” and should not be a cause for concern–with the caveat that he means jar packaging of products made by major companies that use proper preservatives (as opposed to small companies that package their products in jars despite not using preservatives).
My experiment involved buying a set of 10 dip slides often marketed to home lotion makers who sell their products on sites like Etsy, and who need to test that their lotion made from their goats’ milk, for example, isn’t contaminated. Lab tests that certify non-contamination apparently run around $700 per batch and these people need a more cost-effective way to test their batches without major lab equipment.
Dip slides are double-sided agar slides stored inside a shatterproof test tube. Note: the moisture present here is ok apparently–the only cause for concern would be if the agar were dry.
One side has Total Bacterial Count Agar for growing bacteria and the other has Rose Bengal Agar for growing fungus and mold.
The tubes are supposed to be stored at room temperature away from light. 2 days is enough to incubate bacteria with full results present by day 4. Fungus takes up to 7 days. I gave these two weeks just in case. Also because I was tired and lazy earlier. ahaha
I took some precautions to try to provide controls for this experiment. I opened one dip slide and introduced it to my apartment’s air for as long as it would take me to prepare the other slides and then sealed it to make sure that my air wasn’t responsible for false positives.
I took a new jar of one of the creams I was testing and swabbed it to make sure that there would be a finger-free example for the experiment.
This isn’t a sophisticated test. If bacteria, fungus, or mold are present, the slides sprout various blooms, the number corresponding to the amount of contaminant present. If contamination is present you’re not supposed to open the test tubes, I’ve been told.
From what I understand, this test doesn’t cover every possible type of bacteria, mold, or yeast. And I only tested mass-market skincare products that DO contain preservatives. Please DO NOT extrapolate any results from this experiment and apply them to skincare without preservatives. The products that I tested are all creams that I use, which means that they’re made by Korean skincare companies, accepted by many to be at the forefront of skincare innovation.
I do not imagine my little experiment here to be a definitive answer to the question of whether your jars of skincare are contaminated, but rather an experiment-driven contribution to an existing discussion that I hope will continue–especially in the direction of hard facts and experimentation rather than assumptions. I hope that more skincare fans who are able, particularly those with actual scientific training and access to professional equipment, will conduct and share their own tests so that there’s more information about this question. My PhD is in early modern History, so my time in school was not science-focused at all! Help and feedback from trained experts are always appreciated.
I have been able to finally conduct this experiment thanks to you, the readers of this blog, who put up with all of my blog’s advertising and support the blog by clicking on affiliate links when you see something that you want to purchase. I truly appreciate the support and I hope that this post is interesting to you.
RESULTS
Control (exposed to air for as along as it took me to streak the other slides): no visible contamination
Lalavesi Akma Cream Level 2 2014 edition Yerba Mate: no visible contamination
LJH Probiotics Sleeping Cream: no visible contamination
LJH Tea Tree 80 Cream: no visible contamination
Migabee Bee Venom and Propolis Cream: no visible contamination
Nature Republic Super Aqua Max Cream for Oily Skin + actual live probiotics added via capsule: no visible contamination
SN Yeoshin Cream (used): possible minor contamination
I’m really confused about this possible growth because it doesn’t match the red blooms that the diagrams show should grow on this agar to indicate bacterial contamination. To me, this looks more like a yeast growth that should appear on the other (red) side of the slide. Hmm. But when I look at bacterial growths on agar online this is what some of them look like. Experts? Any thoughts on this? What’s weird to me is that this is one spot, whereas the charts seem to indicate that there should be more if contamination is present. I’m confused, to be honest. My thought is that this is bacterial and it represents a small amount of contamination, but nothing rampant, but I’m not confident about this at all.
Today (30 November 2014) I streaked a brand new slide with the used SN Yeoshin Cream to see if I could replicate the results or see something different. I’ll report back and update this post in about one week with the results.
SN Yeoshin Cream (new): no visible contamination
The fresh jar (which was supposed to just provide a general control) of SN Yeoshin Cream does not show contamination. So it’s likely that if that growth on the agar from the used jar really does indicate that there’s bacteria in that cream, the bacteria came from my gross fingers. Awesome!
Conclusion
Out of one control exposed just to my apartment’s air, one control streaked with a newly opened cream, and six tests of jars of cream in which I dug my fingers repeatedly over the course of normal use (my fingers were usually washed, but not to surgeon-like perfection), there seems to be only one possible instance of seemingly minor contamination (hopefully people who know their stuff can give us some more ideas about what’s growing on the SN Yeoshin cream’s bacteria agar). It’s possible that the tests aren’t sophisticated enough to pick up every bit of contaminant ever, but right now I feel pretty confident about continuing to use my creams without a spatula. It seems that if jars of skincare were crawling with bacteria there would be more obvious results.
As I mentioned earlier, I don’t see this as a definitive answer to the question of whether your jars of skincare are contaminated, but rather an experiment-driven contribution to an existing discussion that I hope will continue. I’m sure that experts and other fans will have questions and critiques and hopefully their own experiments, so talk to me (and each other!) in the comments.
This is SUCH an awesome post, thank you so much for taking the time to do this experiment. I’m not one of those crazy germ-obsessed people, so I’ve always dug right into my skincare jars and have never had my skin melt off, so I never worried too much about it. Although when I start hearing people say “I won’t use that lip balm/lotion/etc because it’s in a jar and it’ll get really gross” I started to wonder if maybe I was just misinformed. While you’re right in saying that this probably wouldn’t pick up any and everything, and perhaps that maybe older jars of products (that are almost empty for example) may have a bit more chance of contamination, I think that using a spatula or a clean finger is safe enough, it seems! Thanks again for doing this!
I’ve been digging my fingers into my cream jars for decades and my face hasn’t fallen off. I guess I am lucky that I do not have sensitive skin or issues that would be problematic if there was slight contamination – some people are very hypersensitive to that!
thank you for this blog post – very informative and helpful!
I would be curious to see if the results were substantially different after testing a cream that had been used under less hygenic circumstances. Not washing your hands after going to the bathroom, then digging on in for example…
This is great! Thank you so much for taking the time to do this. I usually use a spatula for my products but it’s nice to know that washed fingers work fine, too!
To answer your questions for you–the pictures in the guide are not representative of bacteria nor mold colonies in general. I assume they were mostly giving an idea of what staph or strep (most common bacteria) may look like. An easy way to understand this is to google pictures of bacterial colonies, and then google pictures of yeast colonies. Almost all colonies have their own appearance, for instance if you were growing pseudomonas you would see a purple-green sheen, and perhaps a smell like grapes or tortillas, whereas proteus has a spreading clear-grey type of colony with a putrid rotten, wet dog smell, and it covers the whole plate even under other colonies. Some colonies are large and spreading, some are small and so pin-point that you may not have even noticed them on your agar. We actually do “lab art” during lab week using different colonies to make pictures–that’s how different some of them are! One of my friends made Starry Night (Van Gogh) on an agar plate). I know the kits are basic, but I think they should add an explanation that all colonies look different and their picture is only representative a certain few so that people don’t get confused and mistake positive growth for no growth just because the colony looks different.
The mold picture is the most accurate in that most molds do blossom in that way, and if you ever get a mold–do NOT open it. Ever. Under any circumstance.
As for your possibly contaminated jar, it’s likely that you contaminated it either by breathing on it/talking, or from ambient air. Of course, the swab also provides that possibility. Another thing–certain applicators do kill certain types of bacteria. For that reason not all swabs can recover the same kind of bacteria from certain body site specimens.
Back to contamination–it happens quite often, and some lab managers won’t even let you talk if you’re plating or opening plates. I’m actually quite surprised your ambient air jar didn’t grow anything, however I’m also skeptical at how much this kit can actually grow due to the fact that this is incubated at room temperature, and the majority of cultures are grown at 37C or higher (body temperature). Your probitiocs may very well still be viable, but perhaps not at room temperature. There are also some bacteria that like “cold” temperatures better, hence why we also have disease causing bacteria in lunch meats and left over potato salad haha. I assumed your ambient room slide would grow some kind of bacillus/mold or corynebacterium, these are very common contaminants.
If you really want to take it a step further, you can buy pellets of live organisms to streak and see if it works. I know I’ve seen vials of staph you can order online from educational sites for pretty cheap. Just be careful if you do and buy something less dangerous!
SampleHime
Great post! I’ve never been one to worry about using spatulas all the time & I know that my hands are usually washed before using skin care products but I’m also not meticulous about it
. This just confirms that I’m fine with the preservatives I do allow in the products I use.
Thank you for this blog post. I feel relief that after all contamination isn´t the huuuuuuuge issue I thought it was! Thank you for clearing this up!!!