Ka UV Sunscreen Sensitive Skin SPF50+ PA++++

Another great benefit? This ingredient is highly photostable so it won't degrade easily under sunlight.

A common myth is that mineral UV filters are widely believed to primarily reflect UV light.

However, modern research shows titanium dioxide absorbs UV radiation like chemical filters (~95% absorption & 5% reflection).

Zinc oxide has great skin soothing properties so you'll likely find this in sunscreens formulated for sensitive skin or babies/children. It is unlikely to cause "eye sting" like other sunscreen ingredients.
Regulatory agencies consider zinc oxide to be non-toxic and safe. It has also been shown to not penetrate the skin.

Unfortunately, this ingredient does leave a visible white cast. This is why mineral sunscreens are often less cosmetically elegant than chemical or hybrid ones.

In cosmetics, zinc oxide can be found in both non-nano and nano-sized forms. The nano version is used to reduce white cast and improve the texture of sunscreen formulas.

There are ongoing concerns surrounding nano-zinc oxide's impact on marine ecosystems and whether it can be absorbed into skin.

Regarding marine ecosystems and coral reefs, there is no conclusive evidence that any form of zinc oxide (or any other sunscreen ingredients) will cause harm. The science is still developing but many consumers are keeping a close eye on this issue.

Please note, many destinations have reef-safety sunscreen rules. For instance, the U.S. Virgin Islands advises all visitors to use non-nano mineral sunscreens.

There has also been some stir about whether micronized or nano zinc oxide has potential photoxicity and absorption through the skin/lungs.

An in-vitro (done in a test tube or petri dish) study demonstrated micronized zinc oxide to have potential phototoxicity. There's no need to fret; the EU Commission's Scientific Committee on Consumer Safety has stated, "The relevance of these findings needs to be clarified by appropriate investigations in vivo." Or in other words, further studies done on living organisms are needed to prove this.

Current research shows zinc oxide nanoparticles do not penetrate intact or sunburned skin. They either remain on the surface or in the outermost layer of dead skin (stratum corneum).

Zinc oxide is one of only two classified mineral UV filters with titanium dioxide being the other one.

Fun fact: Zinc has been used throughout history as an ingredient in paint and medicine. An Indian text from 500BC is believed to list zinc oxide as a salve for open wound. The Ancient Greek physician Dioscorides has also mentioned the use of zinc as an ointment in 1AD.

The safety profile of this ingredient is reassuring; the US CIR Expert Panel concluded D5 is safe as used in cosmetics and Health Canada concluded that D5 is not harmful to human health or the environment as currently used in cosmetics

There's a study that people mention about D5 in a rat study showing tumors. This study is related to long-term inhalation of high D5 levels.

Regulatory bodies have judged this study to be not applicable in topical skincare since skin absorption of D5 is very low and we're not really inhaling huge amounts of D5.

The only restriction for this ingredient is environmental. The European Chemicals Agency (ECHA) restricted D5 in wash-off cosmetics at or above 0.1% due to their persistence in water.

Typical usage concentrations range from 1-5%.

Human testing shows it's non-irritating and non-sensitizing, and the EU Scientific Committee on Consumer Safety (SCCS) has cleared it at very high levels (79% in leave-on products).

The one thing worth knowing about its comedogenic score of 3-4 is to keep it in perspective: these ratings come from old rabbit-ear tests using 100% of pure ingredient and doesn't reflect how it behaves at low levels in a finished product.

Because it is an ester of palmitic acid (C16), it falls into the range that the Malassezia yeast can feed on and is considered not fungal acne safe.

Titanium dioxide provides broad-spectrum protection mostly in the UVB and UVAII range, with some protection in the UVAI range.

While its UVA protection isn’t as strong as zinc oxide’s, the difference is minor.

A common myth is that mineral UV filters reflect UV light. However, modern research shows titanium dioxide absorbs UV radiation like chemical filters (~95% absorption & 5% reflection).

Thanks to its non-irritating nature, titanium dioxide is suitable for sensitive, acne-prone, or redness-prone skin. It is unlikely to cause "eye sting" like other sunscreen ingredients.

A major drawback of this ingredient is its white cast and thick texture. This is why mineral sunscreens often leave a white cast and are less cosmetically elegant than chemical/hybrid sunscreens.

To improve white cast and spreadability, micronized or nano-sized titanium dioxide is often used.

There are ongoing concerns surrounding nano-titanium oxide's impact on marine ecosystems.

There is no conclusive evidence that any form of titanium oxide (or any other sunscreen ingredients) will cause harm to marine ecosystems or coral reefs. The science is still developing but many consumers are keeping a close eye on this issue.

Please note, many destinations have reef-safety sunscreen rules. For instance, the U.S. Virgin Islands advises all visitors to use non-nano mineral sunscreens.

Nano mineral sunscreens once raised safety concerns about absorption into skin.

Extensive research has shown that they do not penetrate healthy or damaged skin; they remain safely on the surface and the top layer of dead skin (stratum corneum).

You'll likely find titanium dioxide bundled with alumina, silica, or dimethicone. These ingredients help make titanium dioxide highly photostable; this prevents it from interacting with other formula components under UV light.

Dimethicone comes in different viscosities:

Depending on the viscosity, dimethicone has different properties.

Ingredients lists don't always show which type is used, so we recommend reaching out to the brand if you have questions about the viscosity.

This ingredient is unlikely to cause irritation because it does not get absorbed into skin. However, people with silicone allergies should be careful about using this ingredient.

Note: Dimethicone may contribute to pilling. This is because it is not oil or water soluble, so pilling may occur when layered with products. When mixed with heavy oils in a formula, the outcome is also quite greasy.

Isohexadecane is often used in products designed to help oily skin. It is lightweight and non-greasy while helping to moisturize. When mixed with silicones, it gives a product a silky feel.

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.

According to manufacturers, this ingredient is an emollient and humectant. This means it helps hydrate the skin.

In medicine, this ingredient is used to help relieve heartburn and help heal ulcers.

There is currently no credible scientific evidence linking aluminum hydroxide in cosmetics to increased cancer risk.

Major health organizations allow the use of aluminum hydroxide in personal care products and have not flagged it as a carcinogenic risk at typical usage levels.

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

The Cosmetic Review Expert Panel has concluded the alkyl benzoate group to be safe as used in cosmetics; it wasn't found to be a skin irritant and unlikely to be absorbed due to its low water solubility.

This report recorded almost 1000 reported uses with concentrations up to 59% in leave-on products but your cosmetics will typically use 0.5-15% depending on the product.

It's often called a "SPF booster": this is because it keeps UV filters properly dissolved and evenly distributed to support a sunscreen's performance. It doesn't actually raise SPF on its own.

Overall, this ingredient is well tolerated.

This ingredient is fungal acne safe because it is an ester of benzoic acid.

Think of this ingredient as two parts stuck together: an oily part and an acid part. Malassezia only gets a meal when it can snip off a fatty acid to eat. With C12-15 Alkyl Benzoate, the acid part is benzoic acid, which isn't a fatty acid and which the yeast can't use as food.

Benzoic acid is actually used as a preservative to stop yeast from growing.

The oily part is a blend of C12-15 fatty alcohols but fatty alcohols in this size range can support only a little Malassezia growth (mostly for one species of Malassezia as well).

In the ingredient, those alcohols stay locked inside the molecule. The yeast can only reach them by snipping the benzoate bond, and that type of bond is harder for it to cut than a normal fatty bond.

So not much gets released. And whatever does get snipped comes packaged with benzoic acid, which discourages yeast growth.

This ingredient is sourced from plant-based oils like soybean or rapeseed.

Clinical studies found no signs of irritation from this ingredient.

Since Isostearic Acid is an 18-carbon fatty acid, it is in the range that Malassezia can feed on. This ingredient may not be fungal acne safe.

You might have seen sources that this ingredient is comedogenic. The original comedogenic testing on rabbit ear actually tested the ester, Isopropyl Isostearate and not Isostearic acid itself. There has been no comedogenic testing done on this ingredient, but it may be worth patch testing if you have acne-prone skin.

Due to its antioxidant properties, trehalose may help with signs of aging. Antioxidants help fight free-radical molecules, unstable molecules that may damage your skin.

In medicine, trehalose and hyaluronic acid are used to help treat dry eyes.

Some animals, plants, and bacteria create trehalose as a source of energy to survive freeze or lack of water.

Urea has the strongest exfoliation effect in concentrations higher than 10%. It is a keratolytic agent, meaning it breaks down the keratin protein in the top layer of skin. This helps remove dead skin cells and flaking skin.

In medicine, urea has been shown to help increase the potency of other ingredients, such as fungal treatments.

Humans and animals use urea to metabolize nitrogen-containing compounds. Urea is highly soluble in water. Once dissolved, it is neither acidic nor alkaline.

Urea is actually one of the more well-studied and well-supported ingredients out there if you have eczema.

Clinical trials have shown that urea creams in the 5 - 10% range can:

Higher concentrations (20 -30%) can also help with thickened, scaly patches but is also more likely to sting on active flares.

Skip urea if you have rosacea. The AAD (American Academy of Dermatology) lists it alongside alcohol, menthol, and fragrance as a potential irritant for rosacea-prone skin. Urea's keratolytic and penetration-enhancing properties can trigger stinging, burning, and redness.

As always, your skin is unique, so definitely check in with your dermatologist.

Other antioxidants found in this oil include tocopherols, tocotrienols, and ferulic acid.

According to manufacturers, this oil has a lightweight texture that absorbs nicely.

The CIR (Cosmetic Ingredient Review) has concluded this ingredient to be safe as used in cosmetics and it has not shown to be a skin sensitizer in testing (unless you have a known rice allergy).

Due to the fatty acids (primarily Oleic Acid ~40%, Linoleic Acid ~30%, and some Palmitic Acid), this ingredient may not be fungal acne safe.

In vitro studies have shown that Oleic Acid is one of the fatty acids that induce rapid Malassezia growth in lab settings.

This ingredient soothes skin inflammation by inhibiting inhibiting a part of the inflammation process.

Marigolds have been used in traditional medicine throughout Asia and Europe.

Interestingly, the size of the molecule affects its behavior:

Some clinical evidence links low molecular weight versions to improved wrinkle depth, elasticity, anti-inflammatory effects, and barrier repair.

Many serums use a blend of both weights so you can get surface hydration plus longer-lasting and deeper effects.

You'll typically see concentrations between 0.1-2% for this ingredient.

Research on a hydrogel with serine confirmed this serine got delivered to your stratum corneum and demonstrated enhanced skin moisturization.

Interestingly serine also helps your skin produce filaggrin, a protein that keeps your skin barrier strong and used to create collagen.

Due to it being edible and tasteless, you'll likely find this ingredient in breath freshener strips. This ingredient is produced from the starch of the fungus, Aureobasidium pullulans.

Pullulan is stable over a broad-range of pH.

Fun fact: This flower is traditionally used in Chinese and Korean medicine.

Tocopheryl Acetate is commonly found in both skincare and dietary supplements.

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.

Your skin makes glycerin on its own (mostly from sebaceous oil breakdown) and shuttles it to your outermost layer of skin, or your epidermis, via aquaporin-3.

Aquaporin-3 is a transporter that is essential for normal skin hydration, elasticity, and repair. Interestingly, mice lacking in AQP3 have dry and less elastic skin that can be fully corrected with glycerin.

This ingredient is non-irritating, plays well with almost every ingredient, and works across all skin types. Typical use is anywhere between 3-10% but can go up to 79% in some leave-on products.

Just know very high concentrations (>40%) can feel tacky in low humidity.

Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.

You might see people debate whether Sodium Chloride is comedogenic, but there actually haven't been any comedogenic tests done on it. Either way, the overall formulation of a product matters a lot more than any single ingredient.

You might see this ingredient used in scrubs as a primary exfoliating ingredient.

Depending on the concentration, it can drastically change the texture of a product from pasty solid (like lipstick) to sprayable liquid.

The CIR Expert Panel for Cosmetic Ingredient Safety has concluded this ingredient to be safe in cosmetics. The highest reported use concentration is 14.2% in lipsticks.

As an antioxidant, it helps fight free-radical molecules. Free-radical molecules are capable of damaging our cells and other genetic material. Thus, antioxidants may reduce the signs of aging.

This ingredient is oil-soluble.

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

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.

This ingredient is used in medicine to help treat low blood levels of phosphorus.