Chemicals of the Day: Preservatives
Today’s Chemical of the Day is actually multiple chemicals: we’re going to talk about preservatives. Preservatives are used in food, cleaning products, cosmetics, personal care products, and medicines to protect product integrity and prolong shelf life. The word ‘preservative’ generally doesn’t have a positive connotation and 'preservative-free’ on a label is considered a positive thing by consumers. But is it?
Why Do Products Need Preservatives, Anyway?
Water breeds life. Unfortunately, that life includes dangerous microbes. Anhydrous products (waterless) may not require the same level of preservatives as water-based products, as anhydrous products generally do not provide conditions under which bacteria, yeast, and fungus will breed (anhydrous products are oil based products made of vegetable oils, butters and waxes ONLY). But every time a container is opened, the product is exposed to airborne contaminants and the germs on the hands reaching into the jar. Even a waterless product can become a breeding ground for microbes when used in a wet environment like the shower. According to The Natural Skincare School:
Many well-meaning beauty and DIY bloggers (some with huge followings) don’t understand the fundamentals behind creating safe products and are posting these potentially hazardous recipes.
Many books are doing the same.
There are homemade products for sale online, in shops, and at craft fairs that are also made by people who don’t understand the fundamentals of making safe products, thereby putting the health of their customers at risk.
But there are rising concerns about the safety of conventional preservatives. Can’t products be made preservative-free and still be safe? Can’t companies just use ‘natural’ preservatives?
Natural versus Synthetic Preservatives
We won't get too much into the preservatives used in food; we'll focus here on cleaning and personal care products. The proliferation of pre-packaged food has made preservatives a necessity. Packaged foods with 'No Artificial Preservatives' labels are typically made or packaged in such a way that preservatives are not necessary. All-natural salt has been used as a food preservative for thousands of years, since most bacteria, fungi, and other potentially pathogenic organisms cannot survive in a salty environment.
But aren’t there natural preservatives for store-bought products cosmetics that can keep these products just as safe as synthetic preservatives? The short answer is, no. Most natural substances are not active against the most threatening microbes: pseudomonads. And even though many essential oils are antimicrobial, in order to be effective they require a concentration in products that would cause irritation to the skin.
Many DIY bloggers, handcrafters, and consumers are confused about what exactly a preservative is supposed to do. A Pinterest recipe might suggest adding ‘Vitamin E Oil’ as a ‘preservative’ in a personal care product recipe, but Vitamin E is an antioxidant, not a preservative (we’ll talk about the difference between the two later).
What about Grapefruit Seed Extract (GSE)? Technically, it’s an antioxidant, too, and the debate rages on as to how natural it really is (some studies show that the only reason it works, when it DOES work, is because of accidental-on-purpose contamination with synthetic preservatives in concentrations found to be as high as 11%. Essentially, it’s these synthetic preservatives acting as antimicrobials and not the GSE). Read in more detail about how Grapefruit Seed Extract is made here: http://www.itmonline.org/jintu/grapefruit.htm
‘But my product is made with coconut oil. It doesn’t need a preservative because coconut oil is a natural preservative’. Maybe – as long as there’s also no water in the product, and you don’t use it in a water-rich environment (like at the bathroom sink). Monolaurin, a substance in coconut oil, is in fact being studied as a potential food preservative if used in combination with other antimicrobial agents (https://www.sciencedaily.com/releases/2009/09/090908103931.htm)
What about glycerin? To be effective as a preservative, you’d need to have anywhere from 50% to 70% glycerin content in your formula – far too sticky for most products! Plus, glycerin isn't always 'all-natural' - it can also be synthetically produced.
Parabens were used for many years and are very effective preservatives. However, some studies showed parabens to be mild endocrine disruptors, and parabens were found in breast tumors. Consumers are increasingly looking for paraben-free products, and companies are responding by discontinuing the use of parabens and replacing them with other preservatives. Here is a more detailed discussion about how safe the new alternatives to paraben preservatives are: http://www.beautifulwithbrains.com/parabens-alternatives-safe-effective/
Methylchloroisothiazolinone (MCI) and Methylisothiazolinone (MIT)
Many companies, like Seventh Generation, Method (the Target brand), and Earth Friendly Products use these two very powerful preservatives instead of parabens. MIT can kill microbes, germs, fungi, and bacteria; MCI has anti-bacterial and anti-fungal properties, too. However, these preservatives are some of the most skin-irritating ingredients on the market (see our earlier blog post).
Most companies use a blend of preservatives to cover the range of bacteria and fungi that might be encountered in a product. Different preservatives do different things; some are effective against bacteria but not mold or yeast, and vice versa. Food-grade preservatives such as sodium benzoate and potassium sorbate are often used in addition to other preservatives.
So what’s the answer? How do we have safe, yet minimally preserved products?
You could make everything yourself, only make an amount that can be used up quickly, and keep things refrigerated. But, it's not realistic that all consumers will make all of their cleaning products, all of their personal care products, and all of their cosmetics at home. Products purchased outside the home are not going away. And products purchased outside the home, whether from a big box store or a craft show, have likely been unrefrigerated and on a shelf for a while before being sold. Therefore, preservatives are necessary, especially in a water-based product (lotions, hydrosols, etc.). If you are purchasing or formulating something that contains water, milks, hydrosols, or other aqueous liquids, the product must contain preservatives or must be refrigerated and used within 3-4 days. It simply is not optional. Water provides a medium for harmful bacteria, mold, yeast and fungi to grow over time. If used, a contaminated product could cause severe health problems, blindness, and even death. Products must be adequately preserved to prevent contamination and microbial growth.
Don’t trust a product label that contains ‘water’ on the ingredient list but also bills itself as ‘preservative-free’ – the company is either dishonest or the product is potentially unsafe. According to Futurederm.com: "In the quest to get safer products for ourselves and our families, I fear the pendulum has swung too far the other way. Some natural and organic
products do not contain adequate preservative systems to cover the full range of bacteria and fungi that may grow under certain conditions imposed by users".
The only time a preservative-free product with some water content might be acceptable is if a major product component was ethyl alcohol or if the product was packaged in an airless pump. It is generally safer to have minimally preserved products in sprayer or pump bottles than in open-mouthed jars with screw-on lids. (Airless pumps are another option for reducing the amount of preservatives required to keep a product safe).
Remember that a contaminated product won’t necessarily look or even smell funny. You won’t necessarily know it’s contaminated. I often hear, “I’ve made this product for years with no preservatives and I’ve never had any issues.” I don’t doubt this to be the case with many small businesses and many products. But it only takes one contaminated product to ruin a business – or worse. 99 times out of 100, not wearing a seatbelt causes no harm at all. But that one time is all it takes. And that’s why, even though we may go through a whole life time without ever being in a car accident, we ALWAYS wear seatbelts. The consequences of not doing so are just too great and not worth the risk. (Read more here about cases of contaminated cosmetics: http://america.aljazeera.com/articles/2014/10/29/cosmetics-recallbacterialcontamination.html).
In the search for eco-friendly, healthier cleaning and personal care options, the answers are often gray, not black or white. Take Norwex and e-Cloth, the microfiber cloths that eliminate the need for cleaning products altogether - you can clean with only water. But microfiber pollution is a growing problem. Synthetic materials shed tiny particles every time they are washed and end up in our waterways. On the other hand, these cloths eliminate the often harsh ingredients in cleaning products and single-use product bottles. Sometimes we're choosing the best option of multiple problematic choices.
With all that said, remember that even if they contain preservatives, products purchased from responsible, knowledgeable handcrafters and local businesses are often still healthier alternatives to mass-produced commercial products because the remaining ingredients within the product are usually higher quality and less harshly preserved.