Unpacking Clean Makeup’s “Mold Problem”

Cosmetic chemists break down fact vs. fiction.

by Elise Tabin
Originally Published: 
clean makeup products

Even though it's 2023, a universal definition of what clean beauty is still doesn't exist. Regardless of what you define clean beauty as — 100% organic, void of synthetics and fragrance, completely sustainable, or anything else that fits the bill — one thing is for sure: the shelf life of clean makeup is typically shorter than traditional color cosmetics. That's because clean versions usually rely on fewer or no preservatives, which can lead to mold and bacterial growth and contamination (more on that in a minute).

While one goal of most clean beauty brands is to be free of potentially harmful chemicals or substances, the lifespan of these products is becoming questionable. Recently, some clean makeup, skin, and hair brands have been the unfortunate recipients of an unsolicited PR blitz. Take, for example, the TikTok-famous Kosas Revealer Concealer and JVN Complete Pre-Wash Scalp Oil. First, concerns about mold in the concealer came to light on Reddit, followed by more outings on Instagram and TikTok. Then, the best-selling scalp oil came under fire for mold issues as well (the brand says mold is confused with turmeric sediment in the oil). As a result, it is being reformulated with a re-release date scheduled for later this year.

With so many beauty and makeup enthusiasts switching to clean products, some trade-offs come with the choice, specifically the potential for items with a condensed shelf life, which occurs for several reasons. Of course, the transiency of clean makeup isn't a reason to give up on it, but there's plenty to know about how long it lasts and other possible issues, especially regarding the health of your skin. Ahead, TZR unpacks the truth about clean makeup with the help of a few cosmetic chemists, including when it's time to toss that beloved lip gloss that may be starting to smell funky.

Does Clean Makeup Really Have A Shorter Shelf Life?

Nothing lasts forever, clean makeup included. While clean makeup bears a shorter shelf life, cosmetic chemist Laura Lam-Phaure says the ingredients, particularly preservatives, that fall under clean beauty-approved lists can turn rancid and expire faster. Preservatives sometimes get a bad rap, but they stabilize formulations (clean or traditional) and control the proliferation of potentially harmful microorganisms, mold, and bacteria. "Products formulated with effective preservative systems allow formulas to last longer. But with the clean beauty movement moving away from safe and effective preservative systems like methylisothiazolinone, DMDM hydantoin, methylparaben, ethylparaben, propylparaben, butylparaben, and isobutylparaben, it is difficult to make clean beauty products safe," she says. "It's not to say clean beauty cannot be safe — it can be — but it is harder." Plus, the higher the level of pigments in clean makeup, critical for product performance, the more difficult it becomes to stabilize the formulas with appropriate preservatives.

Lam-Phaure says the clean beauty movement has caused fear within the beauty industry regarding preservatives, leading many clean beauty brands to use alternative preservatives or none at all. "Some clean beauty brands are even being forced to turn to less studied preservative alternatives to preserve their products." Or, worse yet, go preservative-free, which can cause a makeup formulation to lack stability and the ingredients within the product to expire quickly. "No matter how clean a brand claims to be, claiming to be formulated with ‘no preservatives’ or touting to be preservative-free is a huge health risk and should not be taken lightly," says Krupa Koestline, a clean cosmetic chemist and founder of KKT Consultants, who has been formulating for clean beauty brands for over a decade.

If clean makeup lacks a reliable preservative system, its efficacy and potency will begin to break down from the moment the formula is opened and comes into contact with oxygen. So why do some clean brands formulate with less stable preservatives, knowing the risks? AJ Addae, founder and chemist at Sula Labs, says that for many clean makeup brands to land on retailers' shelves, their products must adhere to a specific "clean" list of ingredients and be void of certain preservatives. "It's common by today's standards for retailers to advise against certain preservatives, such as phenoxyethanol over 1% of the final formulation," she adds. "Also, the use of parabens, which have been historically demonstrated to be great preservatives, and other preservatives such as BHA (butylated hydroxyanisole) and BHT (butylated hydroxytoluene), often used in trace amounts, are left out. When unpreserved extracts are used, it incrementally lessens the preservation amount in a final formula."

When it comes to clean preservatives, Koestline says there is no one magic preservative. Often, cosmetic chemists are at the mercy of using a combination of different preservation systems, which she says helps to ensure complete broad-spectrum protection against microbes. "An effective preservative system that many clean makeup brands look to consists of sodium benzoate and potassium sorbate, [and has been] proven quite effective against mold. However, both ingredients must be converted to their acidic form to be active," Koestline explains. "That means the formula pH needs to be around 4 to remain effective." Other common clean preservatives include caprylhydroxamic acid (Addae's favorite) and phenethyl alcohol. But Lam-Phaure says these ingredients were designed initially as preservative boosters, not to be used independently. "Combining multiple types to ensure broad-spectrum protection can increase the chance of contact dermatitis, which we have seen with phenoxyethanol."

What Other Factors Make Clean Makeup Spoil?

Still, many clean-conscious consumers question whether makeup with clean preservatives is more apt to grow mold or bacteria faster than traditional preservatives, which is still not 100% known. Even if a clean makeup product has a decent preservative system, plenty of other factors can cause it to spoil faster than traditional color cosmetics. Bacteria and fungi, which readily grow anywhere that's humid with available nutrients, can sully clean makeup. Addae adds that a product's pH also significantly affects how long a formula will last. Surprisingly, even a product's packaging can influence its longevity; for example, Addae says some materials, like bamboo, are excellent sources for mold, yeast, and bacterial growth.

The amount of water in a formula can also sway mold formation (more water equals greater potential for mold spores to multiply). Even the amount of "natural" water-soluble materials, such as its electrolyte content and extracts, can cause a clean product to turn. "Anhydrous products, which don't contain water, are far less likely (and in many cases, impossible) to grow bacteria,” Addae adds. “However, anhydrous products are more subject to rancidity and the oxidation of natural oils and butters in the product."

There's also the situational aspect to consider. Most cosmetics are used in non-sterile environments, like a bathroom, where they can come into contact with millions of microbes when opened or making contact with the skin. Applying makeup directly onto the skin also ups a clean product's risk of microbial contamination. "Cosmetics and water-based formulas stored in jars and mists, as well as products with applicators that touch the skin, are more susceptible to spoilage and mold," Koestline shares.

So, is the trade-off for clean makeup worth it? It depends on who you ask. But that also doesn't mean that every clean makeup product under the sun is destined to grow mold quickly or spoil before you can make a dent in the product. Sure, ingredients with a higher concentration of naturally-derived ingredients with weak or no preservatives tend to lose their potency quicker. But it's no different than what we experience with preservative-free food.

What Expired Clean Makeup Looks Like

If a clean makeup product looks questionable, chances are it is. Most of the time, the makeup has gone awry if you see microbial growth within the product's inner packaging or on the formula. However, Lam-Phaure says contamination is harder to detect and usually requires lab tests to confirm its presence.

One dead giveaway that a clean product's time is up is its odor. Anything from a fishy scent to one reminiscent of dirty socks or downright putrid, earthy, or musky likely indicates bacterial growth inside the bottle. Odd-smelling makeup may be accompanied by a film on the makeup, strange-colored spots, a fuzzy or hairy texture, or a slimy or gummy feeling when applying it to the face. But if a product has large moldy growths, Addae says it has likely been spoiled for quite some time.

To add insult to injury, if the color of the makeup changes when it is on the skin, you can pretty much guarantee that the formulation has expired. Addae says when oxygen causes a molecule to pair with oxygen atoms, perhaps from the air, and lose electrons, there can be color, pH, or viscosity changes, which curb the product's efficacy due to less active matter content of the intended active ingredient. "Think of it like an apple rotting and oxidizing or turning brown."

When It’s Time To Toss Clean Makeup Products

Unfortunately, it’s common to hang on to makeup (clean or not) until you retire it or deem it no longer useable — either it crumbles upon application, looks too funky to apply to the face, or smells off. Using expired clean makeup products without realizing it can harm the skin's health. Like how we've become accustomed to checking the expiration date of organic milk and berries and tossing them at the first sign of rancidity, the same rule of thumb should apply to clean makeup.

But that's not to say that every clean makeup product with a funky smell has spoiled. On the contrary, some, like those with raw materials and even sunflower oil, naturally emit a somewhat decaying odor, especially if they are not covered with fragrances or other ingredients.

So how do you know when to part ways with your favorite clean lip gloss and opt for a refresh? Most clean makeup remains safe and stable for about six months after opening (unless otherwise noted). Products that contain an applicator housed within the formula, such as mascara and liquid eyeliner, should be replaced after two to three months since cross-contamination is more likely. You can also look at the packaging for a number known as the period after opening (POA) date, which denotes how long the product is good after opening it. Clean products have shorter POAs due to their formulation. If there isn't one, veer on the side of caution and replace the product.

Lam-Phaure recommends following these rules and not trying to prolong the longevity of your products. "After that, it is a ‘use at your own risk’ type of thing,” she says.

The Dangers Of Using Expired Clean Makeup

The most significant risk of using any spoiled clean makeup product is the potential for irritation, sensitivities, and allergic reactions. While some people experience a reaction right away, others may be less responsive to makeup that has lost its efficacy.

Still, using rotten products can harm the skin and cause serious repercussions. Koestline says pathogenic and non-pathogenic microbes can grow inside a product, and depending on the species, bring about several risks, ranging from mild redness to cellulitis or even a full-blown infection that can spread to other parts of your body. Using expired clean makeup can also cause contact dermatitis, eczema flare-ups, rashes, and acne, and compromise the skin's microbiome.

But there are other dangers of using expired products, like a lack of skin protection in the case of weakened antioxidants and sunscreens when clean makeup formulations contain them. As these ingredients break down and lose their potency, they can increase the risk of photodamage, redness, inflammation, hyperpigmentation, and a weakened skin barrier.

The Bottom Line

At the end of the day, going the clean beauty route may require you to replenish your products more often to avoid using decayed formulas. While it's unknown whether safety and regulation changes will someday better protect consumers from potentially spoiled products, some experts, including Addae, think the Modernization of Cosmetics Regulations Act (MOCRA), recent legislation that purportedly enhances safety, will be beneficial. Until then, if you find yourself replacing your clean makeup products before you finish them, that's OK. Take it as a sign of being an informed consumer who'd rather be safe than sorry.

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