A Guide to Cosmetic Product Preservatives

Preservatives are some of the most controversial ingredients around, but why? Unpreserved or poorly preserved cosmetic products would present a serious public health concern for consumers. And yet ‘preservative-free’ product claims abound? This can lead to the belief that preservatives are not only unnecessary but potentially harmful.  In this post we’ll cover what preservatives do, cases of contaminated products, types of preservatives out there and the legality of these claims. If you currently believe preservatives are nothing but bad news I implore you to read on with an open mind and try to take what I say in the best possible light.

Why are preservatives used in cosmetic products?

Cosmetic products are preserved to keep us safe. No matter how sterile the manufacturing space and packaging are and how careful we are making the products, as soon as water is introduced into a formulation, microbial growth is inevitable. On top of this, even if the product was able to get to you from manufacturer free of microbe growth, you probably aren't bubble boy right? Most likely your products are kept in the bathroom where it steams up every time you hop in the shower. Every time you interact with a product you are introducing it to new microbial life. Without preservatives, each one of these interactions would be comparable to a game of Russian roulette. All it takes is one small group of bad microbes to turn your cream from this



To this

Image from SoapQueen

Image from SoapQueen

At the end of the day, especially in light of how we like to treat our products, cosmetics need to be safe to use during their full shelf life and the only way that’s possible is preservation and challenge testing, to make sure the product can stand up to the microbe pressures of the consumer.

Some of the microbes that have found growing in cosmetic products ranging from lipsticks to lotions include: Pseudomonas sp.(second most common infection in hospitals), Acinetobacter sp (can cause life threatening infections in people who are  immunocompromised), Klebsiella (pneumoniae causing), Citrobacter freundii (can cause life threatening infections in people who are immunocompromised), Staphylococcus aureus & epidermidis (causes Staph infections), Streptococcus sp. (causes strep throat and meningitis), Candida sp. (can cause thrush or systemic infection which kills about 50% of infected), Aspergillus sp. (produces the toxin aflatoxin), and many more.

To exacerbate the issue further, natural products tend to be more prone to microbe growth than conventional ones. There’s typically a lot more bioavailable nutrients for bacteria to feed and flourish on. Our skin may love plant extracts and proteins but unfortunately, so do bacteria. Given that most of the ‘preservative-free’ claims on cosmetic products are in the natural sector, this can become a big problem! To add to this, many people changing to all natural are doing so after a health scare or disappointments with conventional products or drugs.These consumers don’t necessarily have a strong immune system to begin with. At the end of the day, no matter if the product is synthetic or natural, proper preservation is of utmost importance.

So what? What’s the worst that could happen?

Think I’m overstating the importance of preservation in cosmetics? Well, let's talk about some recent cases of cosmetic contamination. In an example presented by Formula Botanica, In Barcelona 2006 at the Universitari del Mar Hospital, five patients were in critical condition due to a bacteremia lower respiratory tract and urinary tract infection. The culprit was the bacterium Burkholderia cepacia, normally lives in soil and water but can spread easily from person to person and present a serious risk for the immunocompromised. Eventually, they found out that the bacteria came from moisturizing lotion that the Intensive Care Unit personal applied to their patients. Further investigation found that the lotion was contaminated at production, shipment or storage. In this case, nobody died, but that’s not always the case. For example, at King Abdulaziz University Hospital in 2009, over fifteen babies were infected with Serratia marcescens from their baby shampoo resulting in one death. Regarding products like eyeliners and mascaras (which are inherently riskier due to how many microbes we introduce per application plus where they’re being applied), there have been numerous cases of consumers going blind from their makeup. Just hop on Google and search ‘cosmetic product recalls from contamination’ and you’ll see that this isn’t just a problem of the past, occurring way too regularly today in 2018.

Now, I’m sorry to be a fear monger here with these examples, but with what we already know about the importance of proper preservation and this growing trend of “preservative free” products I feel public conscious on the issue is in a dangerous place. It’s especially vital that anyone who’s formulating understands this and also helpful for consumers so they know which products to avoid. Outbreaks like the ones above would not only be sad for those affected but could also likely end a small business without the financial backing of the conglomerates in the industry.

So, all products need preservatives?

No all products do not need preservatives. Any formula that incorporates water, with a couple of exceptions, needs a preservative. These products include lotions, creams, shampoos, and makeup. If the product is likely to be contaminated, for example in eyeliner or mascara, even if the product doesn’t have water, it’ll need a preservative. Products that don’t necessarily require a preservative include water-free (anhydrous) products such as balms or oil-based serums, or products that have a very high or low pH, such as castile soap and bar soap. Certain packaging can also help out with lowering your preservative requirements. For example, aerosols have less contact with air and the consumer, therefore, require much less preservation.

For natural formulators, there are a lot of options for you, but creating an effective preservation system can be quite tricky and takes a bit more innovation. For consumers, if there’s water in a formulation and no preservatives, this should be a big red flag. If the product is water-based, stable and lives through its shelf life with a preservative-free claim, flat out they’re lying. For example, companies will often hide their preserving ingredients in the fragrance ingredients/essential oils or in other ingredients not classically defined as a preservative, for example, alcohol. Another trick is using ingredients that have been preserved with a paraben, and only including that ingredient on the ingredient list. I personally think the claim “preservative free” should be illegal on cosmetic products due to how much confusion it’s spreading among consumers, but more on that later.

Preservatives found in cosmetic products.

Common conventional preservatives

The big pro for synthetic preservatives is their broad-spectrum effectiveness at very low concentrations. In addition, many synthetic preservatives are actually less allergenic, especially because they are needed at such low amounts, than their natural counterparts. For the cons, most of the health scares for cosmetics seem to lie within this ingredient category. Below I’ll take you through some of the controversies. While you're going through this section, it’s important to keep in mind a few things. Firstly, these ingredients are used at very low concentrations (e.g. about 0.3% of a formula). Secondly and most importantly, a properly preserved product, with any type of available cosmetic preservative, synthetic or not, will always be safer than an unpreserved or poorly preserved product. Example, would you rather find out you have an allergy or a staph infection?    


Disclaimer: Due to the controversy of parabens today, I feel a little bit uncomfortable publishing this section. With that said, I’m trying to give you correct information and parabens are an important layer of the discussion. In writing this, I tried to remain as unbiased as possible while reviewing all of the available literature. While there are absolutely people writing that parabens are going to ruin the world, I think a more skeptical approach is important. Here’s what I came up with.


Different types include methyl-, ethyl-, propyl-, isobutyl-paraben, etc. Parabens are widely used because they’re very effective at a low dose, especially compared to all the other preservatives out there. They have no smell or color, are very easy to use, and are generally well tolerated by our skin. At the same time, parabens are one of the most vilified ingredients in the cosmetic industry. The scrutiny seems to stem from a 2004 study, which found traces of parabens in breast tumors. It’s important to note that this study didn’t compare levels of parabens in normal breast tissue to cancerous breast tissue. Instead, journalists reporting on this study drew their conclusions based on the assumption that parabens were found at a higher level in individuals with breast cancer. 

Today, parabens are thought to be weak estrogen mimics and potential endocrine disruptors, implicated in a variety of hormonal related problems such as breast cancer, testicular cancer, and declining sperm counts. With that said, in my research through the available literature, most of the conclusions related to adverse health effects were made from anecdotal assumptions or had really unrealistic methods. What do I mean? There hasn’t been a replicated study to show that parabens (especially the ones most commonly used in cosmetics, methyl & ethyl-) cause endocrine or hormonal disruption (especially at the dosage in your cosmetic products) in humans, and there hasn’t been a study that concluded with significant evidence that these chemicals cause the above health issues. Just because it's seen in tissues doesn't mean it's causing harm. Correlation does not mean causation. More studies need to compare paraben concentrations in healthy tissues to diseased tissues, and to determine the actual biological effects (from amounts comparable to our exposure). With respect to the unrealistic methods, most of these studies included mouse models. In the studies, they often included high dose ingestion or frequent application of parabens. I say unrealistic because these would be over 100 times greater concentration for the mice than what’s in an entire cosmetic product. To add, we don’t typically use a product in one application. Instead, we’ll use it over a longer time frame, like a month in the case of shampoo. I’m not going to conclude that parabens are good or bad for our health, but it’s important to know the limitations of the research. More studies need to be done to say conclusively that parabens, at the low levels used in cosmetics, are damaging to our health.

It's worth noting that, with respect to endocrine disruption, while parabens are a weak estrogen mimic, Butylparaben (one of the more estrogenic parabens, these effects increase with carbon chain length/branching) is 10,000 times less potent than estradiol, which they compete with to bind receptors to have an estrogenic effect. Due to a rapid metabolism of parabens, if they do have estrogenic effects, it's probably not through directly activating estrogen receptors.

More concrete troubling conclusions seem to lie within environmental studies. For example, although more than 90% of parabens are removed from our wastewater via treatment plants, they’re still very frequently found in aquatic ecosystems across all of our oceans, particularly methyl- and propylparaben, despite being biodegradable. With that said, while they are found throughout our worldwide aquatic ecosystems, we don't really know if they're actually having an adverse effect on them. More studies need to be done, again, to determine the biological impacts of these ingredients. Given how much more potent our own hormones are, especially when we take things like birth control pills, how do parabens interact with the environment compared to our pee? So many questions yet to be answered.

In cosmetics, many paraben types have been tested to be well tolerated on our skin up to levels of 25%. In contrast, these ingredients typically range from 0.01 to 0.3% in a product. After extensive testing, parabens seem to be the least allergenic preservatives on the market. But, because of some of the research mentioned above, there’s been incredible pressure on the industry to find alternatives. Unfortunately, the alternatives are often more allergenic… which isn’t good news for our emerging skin allergy epidemic. This epidemic may be being driven by antibacterial agents, like parabens and other preservatives, by altering our skin microflora? There’s so much going on here and so much uncertainty now that we’re learning more about our bacterial inhabitants (Read our guide to the skin microflora here!).

Formaldehyde Donors:

Different types of formaldehyde donors include DMDM hydantoin, imidazolidinyl urea, and glutaraldehyde. After parabens, these ingredients are the next most common preservatives and are often used now as a paraben replacement. Note, many of these products are further greenwashed by making ‘paraben-free’ claims on their labels. Formaldehyde, in general, was once commonly used as a preservative due to its effectiveness, but due to toxicity, allergenicity and carcinogenicity concerns, this ingredient type is no longer used. Instead, formaldehyde donors were developed. Formaldehyde instead dissociates into formaldehyde when put into a water solution. Since these ingredients still result in formaldehyde in the end product, a different preservative type would be my personal reference.

Phenol derivatives:

This includes phenoxyethanol. Today, phenoxyethanol has become the primary paraben replacer in more natural formulations due to its effectiveness at a low concentration in end formulas. With that said, most certifying bodies deem phenoxyethanol as a taboo ingredient in natural products. This ingredient is a synthetic, not that I think that’s a necessarily a deal breaker, but manufacturers should be honest to their customers with their claims. We’re just trading one synthetic ingredient for another.  As for potential risks for this ingredient,  most of the health research has been focused on the above two ingredients, there’s not a whole lot of toxicology-related research on phenoxyethanol. With that said, there’s been a growing number of skin allergies related to this ingredient. According to Lene Still (co-founder of AllergyCertified) in a podcast interview we did in November 2017, she anticipates that with the sheer number of manufacturers switching to phenoxyethanol and with its potential allergenicity, that phenoxyethanol will become a common allergen in about a decade (click here to listen to the podcast episode with Lene!). Food for thought. 

More Natural Preservatives

The biggest con for ‘natural’ (note, more commonly ‘nature identical’, e.g. sodium benzoate) preservatives are that they’re less effective than the above synthetic preservatives. For example, most aren’t broad spectrum and have to be used at a much higher dosage to be effective. As a result, more skill from the formulator is important to create a preservative system with multiple natural preservatives working together to achieve broad-spectrum protection. In addition, many natural preservatives can be quite allergenic, especially at higher concentrations, depending on the ingredients. Natural preservatives are generally a lot more expensive than their synthetic counterparts. Since most natural preservatives are weak acids, for example, salicylic acid, sorbic acid, lactic acid, citric acid, benzoic acid, etc., they’re typically only stable under a pH of around 5-5.5, which can pose a challenge for products with a higher pH, e.g. tear free shampoo, or even just general pH drift (e.g. you pH adjust to 5.5, the product still may increase or decrease in pH throughout the course of its shelf life). Finally, natural preservatives can add a scent or color to your product, which isn’t necessarily a bad thing.

Note, if an ingredient has a preserving effect, I would classify it as a preservative. You can also be like Lush and say self-preserving… but again, the claim ‘preservative-free’ is complete BS

NOT a preservative

Antioxidants are NOT preservatives. I see them popping up more and more in natural water-based formulas, mostly with home and Etsy crafters, and this is a big concern. While antioxidants can be used to extend the shelf life of an oil and help prevent it from going rancid early, they do not have antimicrobial qualities. Examples of common antioxidants include grapefruit seed extract, rosemary extract and vitamin E. There’s other reasons to add these ingredients to your formula, but preservation isn’t one of them.


Preservative-Free Claims

If there’s a claim in the cosmetic industry that irks me the most, this is probably it. A truly preservative free product would present a serious health risk to consumers. Manufacturers making these claims either don’t know what they’re doing or do and are marketing a lie at worst or misinformation at best, to appease the trendy nature of the industry. If a water-based product is stable and can survive through its shelf life with all of the pressures of the consumer, there is no possible way for this to happen without a preservative. Again, products without water don’t necessarily need a preservative. It seems many manufacturers are using loopholes in the law to make these claims. Even if an ingredient isn’t one of the classic “preservatives” out there for manufacturers, if it has an antimicrobial/preserving effect, it is by definition a preservative. There are also techniques like 'natural hurdle systems' that make the whole formula inhospitable to microbes via things like a low formula pH in combination with different extracts, essential oils, etc. While these systems are very innovative and would be my personal preference for preserving, they are just that, preserving. I honestly don't see why manufacturers who've developed these cool natural hurdle systems don't advertise it. More often, I find that they stick to fear mongering... 

Definition of preservative from the Merriam-Webster Dictionary: something that preserves or has the power of preserving; specifically: an additive used to protect against decay, discoloration, or spoilage

 These deceptive claims have created an immense amount of confusion for consumers and have ultimately perpetuated a lot of misinformation. I am not a fan of fear mongering marketing tactics like this. Furthermore, I personally think that this claim should be illegal. It’s worth noting that many international agencies agree. In Europe, there’s currently talk of banning this type of deceptive free-from marketing. 

As required by the EU Cosmetics Regulation (EC No 1223/2009, Article 20), the acceptability of a claim made on a cosmetic product is determined by its compliance with the common criteria (Legal compliance, Truthfulness, Evidential Support, Honesty, Fairness and Informed decision-making). The EU Commission and the EU Member States published a revised version of the guidelines for the application of the common criterion including ‘free from’ claims (annex III).

Accordingly with respect to preservatives:

  1. ‘Preservative free’ is wrong if the product contains an ingredient, not in the official list of preservatives (Annex V) but having antimicrobial properties.

  2. This claim is acceptable except if the product contains an ingredient having properties of this ingredients family as a side function.

Note, this isn’t legally binding yet, but I don’t think manufacturers can plead ignorance in the EU with these recommendations available. Read more here.

Today this potential ban is still a work in progress, but it seems to be a possible decision by the European Commission over the next few years. Should Canada follow suit?  

And that’s a wrap! As always, if you have any comments, queries, conundrums or concerns, leave them in the comments section, on any of our social media feeds @theecowell or shoot us an email!


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