Despite the relatively recent shift toward “clean,” there are still many questionable ingredients to avoid in skincare. These often provide little nourishment or functional benefit and are included only because they are cheaper and more widely available than the myriad plant-derived natural alternatives.
When research raises concerns, we think it's long past time we listen. Which is why, at Prima, we are committed to using 100% clean ingredients rather than the toxic but convenient alternatives. Our refusal to settle is so ingrained in our ethos that we have set a new industry standard by banning over 2,800 problematic ingredients from our products.
Because your skin deserves better. Period.
It’s quite the list, so where should you start? What are some major “red flags” to know in the skincare aisle? Let’s start with the top 11 contenders.
Top 11 Skincare Ingredients to Avoid and Why
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Ethanolamines (DEA, TEA, MEA, ETA)
Ethanolamines are a family of organic compounds derived from two chemicals: ammonia and ethylene oxide. They are highly water-soluble, which means they can easily be absorbed through the skin.
Why are they used in skincare?
Ethanolamines have a unique molecular structure that makes them very good emulsifiers. Emulsifiers are a broad class of ingredients used to promote the dispersion of oils in water and to help stabilize formulations.
They can also provide pH buffering to help bring a product within an acidic range more suitable for skincare. Ethanolamines pop up a lot in foams, shampoos, lotions, creams, and more. You might see these appear on skincare labels as:
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Monoethanolamine (MEA)
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Diethanolamine (DEA)
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Triethanolamine (TEA)
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“Various ethanolamine salts”
What's the issue?
The problem may not be ethanolamines themselves, but how they react when mixed with other ingredients, especially compounds called nitrosating agents. These agents can show up as impurities from other ingredients or may slip in during manufacturing. When they interact with ethanolamines, they can form compounds linked to cancer.
Canada and the EU have both banned the use of DEA in cosmetics, while the US technically allows it, but with certain restrictions. It’s very possible to see DEA or its many related alternatives on labels, despite their carcinogenic tendencies.
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Food, Drug, and Cosmetic (FD&C) Colorants
Commonly called FD&C colorants, these are a family of nine synthetic, FDA‑approved dyes and pigments used to add color to foods, drugs, and cosmetics, including makeup and skincare.
Why are they used in skincare?
You’ll find FD&C colorants widely mixed into makeup and, to a lesser degree, some everyday skincare products, like cleansers and moisturizers. In cosmetics, these synthetic colors allow manufacturers to precisely adjust shades and maintain batch consistency. Unfortunately, in makeup, they are close to unavoidable unless you see a label with “natural pigment only.”
This type of colorant is less common in skincare, but when it does appear, it’s usually because a brand wants to make the color more appealing or to add a signature tint.
A few examples of what to look for on product labels:
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FD&C Red No. 40
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FD&C Yellow No. 5
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FD&C Blue No. 1
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FD&C Red 40 Lake
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D&C Red No. 33
What's the issue?
The main concern about synthetic dyes like FD&C colorants is that they are almost always derived from petroleum. For most people, petrol products are already an unappealing source for skincare ingredients, but FD&C colorants in particular are linked to higher rates of skin irritation. Not to mention, they provide no benefit to skin function.
Plus, several FD&C colorants are known carcinogens. In fact, Red No. 3 is already banned in cosmetics and skincare for this very reason.
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Formaldehyde
Formaldehyde is one of the more recognizable names on this list of ingredients to avoid in skincare. But what is it? This highly reactive gas, when dissolved in water, forms a byproduct called formalin. It’s used widely across industrial applications, consumer goods, and skincare.
A related class of ingredients is called formaldehyde‑releasing preservatives or formaldehyde donors. These are compounds that slowly decompose, releasing small amounts of formaldehyde over time.
Why is it used in skincare?
Yes, it's true: formaldehyde often finds its way into skincare, but sometimes not in the way you might expect. Why on earth would it pop up in your moisturizer or lotion? Formaldehyde is not only cheap, but it also has powerful preservative qualities. When included in water-based products, it can help prevent the growth of bacteria, mold, and yeast.
Then there are the formaldehyde‑releasing preservatives, which perform the same job as formaldehyde (product preservation), but release formaldehyde only as they degrade. Here are a few of the formaldehyde donors you may see on skincare labels:
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DMDM hydantoin
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Imidazolidinyl urea
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Diazolidinyl urea
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Quaternium‑15
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Bronopol (2‑bromo‑2‑nitropropane‑1,3‑diol)
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Sodium hydroxymethylglycinate.
What's the issue?
Formaldehyde is a known carcinogen — full stop. And ingredients that slowly release formaldehyde over time also raise concerns.
The good news is that this class of ingredients, both formaldehyde and formaldehyde donors, is quickly fading from skincare products, in part because there is no acceptable form of long-term exposure and because they can cause dermatitis, even at low levels of exposure. There have long been safer ways to preserve the integrity of water-based skincare products without compromising your health or skin function.
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Isothiazolinones
Isothiazolinones are synthetic compounds that disrupt microbial conditions and are used as an affordable preservative across many industries. They are often used in detergents, paints, glues, and other water-based products, including skincare.
Why are they used in skincare?
Isothiazolinones are yet another family of preservatives that may appear in cheaper skincare products because of their ability to prevent bacteria, mold, and algae from growing in water‑based formulations. In haircare, lotions, and more, they may be added to extend shelf life. Here is what to look for on the label:
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Methylisothiazolinone (MI)
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Methylchloroisothiazolinone (MCI)
What's the issue?
This cheap ingredient is among the most problematic preservatives because of its tendency to sensitize skin and its frequent association with contact dermatitis. The issues are well-documented enough that the EU has banned the most common isothiazolinones from leave-on cosmetics like lotions, moisturizers, and more. There are far safer alternatives to protect water-based skincare products that won’t harm your skin.
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Nanoparticles
Nanoparticles (especially those under 100nm) are intentionally engineered particles that are used in pharmaceuticals to improve delivery, absorption, and stability. These tiny particles can penetrate areas that the original ingredient often cannot. They have recently moved from pharmaceutical applications to consumer goods, such as sunscreen and wellness products.
Why are they used in skincare?
Nanoparticles are frequently used in skincare products to enhance their performance. For example, UV blockers like zinc are milled so finely into a nanoparticle that they become almost transparent and won’t leave a white cast on the skin. They are also used in topicals that contain pharmaceutical ingredients, as nanoemulsions may improve penetration and absorption.
What's the issue?
Nanoparticles make our list of toxic skin care ingredients because so much about how they interact with the human body is unknown and untested. This is a problem because nanomaterials are so small that they begin to behave differently from the original ingredient.
Normally, skincare works strictly on the surface of the skin. The particle sizes of the normal ingredients are too large to penetrate the epidermis and deeper into the body. But this isn’t always the case with nanoparticles.
What happens when nanoparticles are used? They may be small enough to enter the bloodstream, and so far, no standardized tests exist to determine if non-toxic topical ingredients suddenly become toxic at this smaller size. When absorption behavior isn’t fully understood, we take the more conservative approach and leave them out.
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Parabens
Many are familiar with parabens as a type of candle wax; you may even have a few paraben tea lights sitting around your house right now. But once again, this is a family of synthetic preservatives derived from petrochemicals.
Why are they used in skincare?
Like other synthetic preservatives, parabens are used in skincare to stop bacteria, mold, and yeast from growing in water-based products. Commonly used parabens in skincare and cosmetics include:
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Ethylparaben
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Butylparaben
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Methylparaben
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Propylparaben
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Isobutylparaben
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Isopropylparaben
What's the issue?
For years, there has been an ongoing debate about whether parabens disrupt hormones. Multiple studies have shown they have the ability to mimic estrogen, binding with estrogen receptors to potentially throw the body’s own internal regulators into a tailspin.
Given the widespread inclusion of parabens in common over-the-counter skincare products, this daily exposure isn’t a risk we’re willing to take.
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Polyethylene Glycols (PEGs)
Polyethylene Glycols (PEGs) are yet another class of synthetics used widely in skincare, this time as solvents and emulsifiers. At this point on the list of bad skincare ingredients, it’s not surprising to hear that PEGs are also derived from petrochemicals.
Why are they used in skincare?
In skincare, PEGs are mainly used in products as cheap “helpers” to enhance the consistency and effectiveness of the active ingredients. For example, they may make lotions more moisturizing, ingredients more stable, or help other ingredients work better through improved absorption.
PEGs are easy to spot on labels because they are listed as numbered versions of PEG. For example:
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PEG-4
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PG-90
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PEG-8000
What's the issue?
On the surface, the PEG molecule itself isn’t usually the problem. Instead, it's the process used to make PEGs that can leave behind trace contaminants, such as ethylene oxide and 1,4‑dioxane, both of which are classified as carcinogens.
And because PEGs break down the skin's natural barrier to improve the absorption of other ingredients, they might actually increase the risk of absorption from those very same contaminants. You shouldn’t have to resort to petroleum-adjacent synthetic ingredients that disrupt the skin’s natural defenses.
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Petrolatum
As its name suggests, petrolatum is another petroleum-derived product. It has a jelly-like texture and is produced by refining heavier crude oil. Petrolatum is used across dermatology for its thickness and because it doesn’t go rancid when exposed to air.
Why is it used in skincare?
In skincare, petrolatum works as a powerful occlusive, locking in moisture beneath a protective layer to shield damaged or sensitive skin. Dermatologists widely rely on it for barrier repair, and it’s often found in lip balms, diaper creams, and surgical recovery products.
What's the issue?
The number one issue we have with petrolatum is that it's another petroleum-based product. In our opinion, they all come with sustainability and contamination concerns. But petrolatum is also a problem due to its highly occlusive properties. It's heavy and greasy, trapping everything, good or bad, under a thick barrier that simply provides an illusion of moisture. Instead, we choose ingredients that actively support skin health and moisture retention, rather than simply coating it.
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Mineral Oil
Need another bad ingredient in skin care to banish from your cupboards? Enter mineral oil, a highly refined petroleum-derived chemical. It exists in skincare but is used across industries as an industrial lubricant, machining fluid, and household cleaner.
Why is it in skincare?
When you see mineral oil listed in skincare, it’s likely included as a cheap ingredient to improve product slip and reduce moisture loss. Or it might simply serve as a vehicle for other ingredients.
What's the issue?
These days, most of the more serious health issues associated with mineral oils have been resolved as the industry moved toward highly refined cosmetic-grade versions. But quality and sustainability concerns are still valid issues we care about.
Considering this is yet another ingredient derived from petroleum that continues to be used in skincare, we think there are still questions worth asking. Do we really need to rely on petrochemicals in our daily skincare routine? Considering there are so many safe, effective, plant-based alternatives, in our opinion, it doesn’t make sense to use mineral oil or any other petroleum-based product for skincare.
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Phthalates
Phthalates are another category of synthetic ingredients that have become prevalent in scented products, like skincare. Although originally developed to soften plastics like PVC, phthalates are often used in fragrances to help them last longer.
Why are they used in skincare?
Unfortunately, unless you see “phthalates-free” somewhere on the label, it can be really hard to tell whether it’s hidden in the ingredient list. This is because it’s often rolled into a vague "fragrance" or “perfume” language.
Many fragrances contain phthalates, yet they never appear on the label. This is because if a brand has purchased its fragrances from a third-party manufacturer, the full ingredient composition can be classified as a trade secret. So, it’s very hard to decipher what's actually in that scented daily moisturizer or face cream. In the few instances where a phthalate has been listed, you may see it under:
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Diethyl phthalate (DEP)
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Dibutyl phthalate (DBP)
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Dimethyl phthalate (DMP)
What's the issue?
Just like parabens, phthalates must be added to the growing list of endocrine disruptors in cosmetics. They are also reported to cause reproductive toxicity. Even with studies showing altered male reproductive development and reduced sperm quality, so far, phthalates remain widely used in the US cosmetics industry. Yet, interestingly, they’re no longer allowed in children's products, including plastic toys.
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Synthetic Fragrance
Synthetic fragrances are a vast array of human‑made aromatic chemicals (alcohols, esters, aldehydes, musks, etc.) often derived from petrochemicals or extracted from natural compounds. Hundreds of common fragrancesfall into this category.
Unlike naturally derived scents, synthetic fragrances are a dime a dozen, and they’re incredibly easy to get in huge quantities. Which means, more likely than not, you currently have dozens of products in your home that rely on synthetic scents for their tell-tale aroma. Think cleaners, personal care products, and even luxury perfumes.
Why are they used in skincare?
Synthetic fragrances remain one of the cheapest, easiest ways to amp up scent in skincare. From a marketing perspective, scents make products more appealing, and signature scents are a common branding tool. Yet, all too often, the added fragrance doesn’t add any benefit. It doesn’t help your skin recover, lock in moisture, or restore function.
What's the issue?
Many fragrances are irritants and can cause outbreaks, allergic reactions, and dermatitis. More seriously, some specific compounds within this category are known carcinogens, hormone disruptors, and neurotoxins.
But even if you know which scents to avoid, the problem is that a single synthetic fragrance can contain dozens of undisclosed chemicals. On the label, all you’ll see is “fragrance.” In the US, this fragrance loophole makes it hard to avoid specific ingredients and complicates independent safety assessments. But that’s not good enough. At Prima, if we can’t clearly name it and understand it, we won’t use it.
100% Clean. For Real
At Prima, we’re fully committed to transparency when it comes to our ingredients. Yes, we follow clean beauty standards, but we also follow up that commitment with sustainable sourcing, testing, and all-around higher standards than most
We've banned over 2,800 questionable skincare ingredients for a reason — because your long-term health matters more than any cheap formulation shortcut. We take a very strong stance on toxic skincare ingredients.
We are purity pioneers. Science champions. We are 100% clean.
