Equate Beauty All Day Moisturizing Sunscreen Lotion for Normal Skin, Broad Spectrum SPF 15 Versus Olay Complete All Day Moisturizer Sensitive Skin SPF 15

On top of that, this ingredient can counteract the effects of hard water by binding to the minerals in it.

One thing worth knowing is that Disodium EDTA has been shown to be a mild penetration enhancer. It can help other ingredients absorb into skin more effectively which can be a double-edged sword (great for actives, but can also make the active too strong if you have sensitive skin).

Clinical patch testing showed no significant skin irritation at typical use concentrations and minimal dermal absorption.

You'll most likely see this ingredient near the end of an ingredient list. It's typically found in concentrations less than 1%.

DMDM Hydantoin is approved for use in cosmetics all around the world.
In the EU, this ingredient is allowed in personal products up to 0.6 percent.

You might have heard of the class-action lawsuit about it causing hair loss. According to chemists, there has not been a link found between this ingredient and hair loss.

The Hydantoin part of this ingredient is created by reacting glycolic acid and urea.

You can check out alternatives to Dmdm Hydantoin:
phenoxyethanol, potassium sorbate, and sodium benzoate.

UVB (290-320 nm) rays emit more energy than UVA rays. They are capable of damaging DNA, causing sunburns and are thought to be linked to skin cancer.

The state of Hawaii has banned sunscreens containing octinoxate due to its potential impact on coral reefs. More research is needed to bridge gaps in this research. The European Union allows higher levels of octinoxate in sunscreens than the US and Australia.

Ethylhexyl Methoxycinnamate is oil soluble. It is not stable and may lose efficacy when exposed to sunlight.

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.

It is typically used at very low levels in cosmetics, with most formulations using 0.0125% or less (well below its approved maximum).

In the EU, IPBC concentration limits are set at 0.02% in rinse-off products and 0.01% in leave-on products.

Though IPBC is a relatively uncommon contact allergen, patch testing studies show positive reaction rates ranging from 0.3%-0.9% of patients tested. This is still quite low compared to preservatives like methylisothiazolinone which sits at around 4-5%.

Researchers note that existing iodine sensitives or rubber allergies may be the cause of this as IPBC shares a structure with both thiuram (used in rubber) and iodine.

Be sure to patch test if you are unsure and speak with a medical professional about using this ingredient.

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.

In testing, this ingredient was nontoxic in acute oral studies and not a skin irritant or sensitizer.

You might hear concerns about 1,4-dioxane as a byproduct of ethoxylation; this is well-known in the industry and is controlled through purification steps before the ingredient is blended into finished products.

You'll most likely see it paired with steareth-2 because the two work together to create stable formulations.

1,4-dioxane is often brought up as a concern but this is usually removed through purification.

Fatty alcohols are usually derived from natural fats and oils and therefore do not have the same drying or irritating effect as solvent (ethanol) alcohols.

The FDA allows products labeled "alcohol-free" to have fatty alcohols.

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

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!

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.