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Hydrogenated Polyisobutene is often used as a mineral oil replacement.

The cosmetic grade stuff is highly refined with a solid safety record. The CIR Expert Panel has repeatedly reaffirmed this ingredient to be safe in current practices of use and concentration.

The worry about carcinogenic compounds only applies to industrial grades, not the purified version used in skincare.

Despite its reputation, the highly reformed form is non-comedogenic and doesn't penetrate deeply into skin.

The good news for fungal-acne prone folks: the Malassezia yeast feeds on fatty acids and lipids and paraffin doesn't contain any of these (so there's nothing for the yeast to metabolize). This ingredient is considered fungal acne safe.

Fun fact: This wax has the highest melting point of all natural waxes and low solubility.

Typical use concentrations range from 0.5-5%, but can go up to 10% depending on how firm the gel is.

Because it's an ester built on a fatty acid, it may not be fungal acne safe.

You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Remember to stay hydrated!

Like other AHAs, malic acid gently removes the top layer of dead skin cells to reveal smoother, brighter skin underneath.

Though it’s considered milder and less potent than glycolic or lactic acid, it can help improve:

Due to its larger molecular structure, it penetrates the skin more slowly and is often used in combination with other AHAs to enhance their overall effectiveness.

Malic acid often plays a role in balancing a product’s pH and is usually included in small amounts (around 1-2%) as a supporting exfoliant.

As with all exfoliating acids, you should wear sunscreen daily when using malic acid to protect your newly resurfaced skin.

Fun fact: Malic acid is the compound responsible for the tart flavor of apples and other sour fruits.

While research on malic acid is limited compared to glycolic or lactic acid, it’s still a safe and mild exfoliant.

Read more about some other popular AHA's here:

Terpinen-4-ol is responsible for tea tree oil's broad-spectrum antimicrobial activity and makes it a well-researched option for acne.

Clinical studies support 5% tea tree oil as an effective topical treatment for mild to moderate acne. A study with 124 patients compared 5% tea tree oil gel to 5% benzoyl peroxide and both reduced acne (though tea tree oil worked more slowly).

Besides acne, it is also seen in anti-dandruff shampoos and scalp treatments for it's antimicrobial and anti-seborrheic properties.

Safety-wise, the allergic potential of low concentrations on healthy skin is considered low. However, oxidized (old or improperly stored) tea tree oil is a stronger sensitizer.

Irritation can also occur if using the undiluted oil on skin; it's best to use this ingredient as part of a carefully crafted cosmetic formula. This is because regulations require tea tree oil in cosmetics to be stabilized to prevent degradation.

This ingredient has been deemed safe up to 2% in shampoo, 1% in cleansers, and 0.1% in face cream by the EU's Scientific Committee on Consumer Safety (SCCS).

There is some lab evidence that tea tree oil is antifungal against Malassezia, but it is a supportive option at best and not a replacement for proven antifungal treatments.

Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.

Squalene is also naturally present in olive oil and exhibits moisturizing and antioxidant properties.

The polyphenols in olive oil also show anti-aging promise; one clinical study found a measurable improvement in skin appearance after 30 days of topical serum use.

Just be aware that applying olive oil directly to skin can weaken the barrier and cause redness. One study with volunteers found even people without sensitive skin experienced a significant reduction in stratum corneum integrity and induced mild erythema.

It's best to use this ingredient as part of a carefully crafted formula (instead of putting it on skin directly from the bottle).

Because it has a 2-3 on the comedogenic scale, it is a moderate risk for acne-prone skin. However, the overall formulation of a product matters more than a few ingredients with comedogenic ratings.

This ingredient may not be fungal acne safe because of the oleic and palmitic acid content. These fall within the C11-24 fatty acid range that the Malassezia yeast can metabolize to grow.

Overall, olive oil is a well-studied and nourishing skincare ingredient.

The unique structure of silica enhances the spreadability and adds smoothness, making it a great texture enhancer.

It is also used as an active carrier, emulsifier, and mattifier due to its ability to absorb excess oil.

In some products, tiny microneedles called spicules are made from silica or hydrolyzed sponge. When you rub them in, they lightly polish away dead skin layers and enhance the penetration of active ingredients.

There are a very small number of reported cases of contact dermatitis in cases linked to wound-care creams used over compromised skin (rather than skincare).

Overall, this is a well-studied and low-risk preservative just doing its job.

Typical concentrations run up to 0.6%, which is also the maximum amount permitted under both EU CosIng regulations and US FDA guidelines.

This is also one of the most heavily studied preservatives out there and major regulatory bodies have repeatedly given it the green light.

In 2023, the EU's Scientific Committee on Consumer Safety (SCCS) confirmed that this ingredient is safe up to 0.4% on its own, of up to 0.8% when mixed with other paraben esters.

Here's the science behind the noise behind parabens/hormones as well:

Methylparaben shows very weak estrogen-like activity in vitro tests (more than 1,000x weaker than your body's own estradiol). In vivo (live-organism) studies don't support a meaningful endocrine-disrupting effect either.

You get a stronger estrogenic effect from eating tofu, actually.

It's also a low sensitizer and allergic reactions are uncommon; they usually happen on damage or broken skin.

There is a caveat: France has proposed to formally re-examine its endocrine classification in 2025 so the regulatory conversation isn't fully closed as of yet.

But as it stands today, this ingredient is considered safe at permitted levels.

In the US, this ingredient can only be used if it meets strict FDA specifications. Certain versions even require batch-by-batch certification after extensive safety evaluation.

In the European Union, this ingredient is permitted as a colorant and classified as a "nanomaterial" based on its particle size (meaning it requires deeper assessment).

The EU Scientific Committee on Consumer Safety (SCCS) has reviewed nano-sized carbon black specifically and concluded that it does not pose a risk to human health when used in cosmetic products applied to healthy, intact skin and formulated to avoid inhalation.

Studies support this regulatory stance. Laboratory studies on nano-carbon black show potential for cytotoxicity and inflammatory effects in immune cells; it is important to highlight these findings are based on in vitro (not done on a living organism) testing or inhalation scenarios rather than normal topical cosmetic use.

Occupational studies involving industrial workers exposed to airborne carbon black have not shown a clear link between cumulative exposure and cancer risk. These findings are not directly applicable to cosmetics; cosmetic formulations bind pigments within creams, gels, and liquids that are not inhaled.

Overall, evidence shows that this ingredient is safe under regulatory guidelines and purity standards, especially when formulated to avoid airborne exposure.

Even with regulatory approval and a long history of use, some consumers might prefer to avoid ingredients that are petroleum-derived or that fall under the “nanomaterial” category.

Choosing whether to use CI 77266 isn’t necessarily about safety alone; it can also be about personal philosophy, comfort level with synthetic versus natural ingredients, and how much weight you place on ongoing research and regulatory oversight.

Makeup is highly individual, and personal preference plays an important role in deciding what feels right for you.