Sacheu Beauty Eyeliner Stay-N

The CIR Expert Panel has confirmed this ingredient to be nontoxic and clinical studies show no sensitization at cosmetic use concentrations.

True allergic reactions are quite rare: a 15-year retrospective study of 6,751 patients found only 0.31% had a positive reaction (and less than half were considered clinically relevant).

It seemed that when sensitization does occur, it's most commonly linked to topical medication (like corticosteroids) and not cosmetics. Allergic contact dermatitis also appears largely limited to individuals with underlying skin conditions.

Overall, propylene glycol is a well-studied ingredient that most people can tolerate without issue.

Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.

It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.

This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.

This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.

In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.

Concentrations usually range from 0.1-1% in most leave-on products.

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.

Because it is not a free-fatty acid or alcohol, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).

This property also makes Pentylene Glycol a great texture enhancer. It can also help thicken or stabilize a product.

Pentylene Glycol also acts as a mild preservative and helps to keep a product microbe-free.

Some people may experience mild eye and skin irritation from Pentylene Glycol. We always recommend speaking with a professional about using this ingredient in your routine.

Pentylene Glycol has a low molecular weight and is part of the 1,2-glycol family.

Antioxidants help fight free-radical molecules. Free-radical molecules are capable of damaging our cells and other genetic material. Antioxidants help stabilize free-radicals by donating extra electrons. Grape seed extract may help reduce the signs of aging.

The antimicrobial properties of grape seed may help treat acne. However, more research is needed to support this claim.

Grape seed has also been found to help absorb UV rays. Grape seed extract should not replace your sunscreen.

Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.

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.