Pure & Free Liquid Spf 50
Neutrogena Pure & Free Liquid Spf 50Ingredients explained
Titanium Dioxide is one of the two members of the elite sunscreen group called physical sunscreens (or inorganic sunscreens if you’re a science geek and want to be precise).
Traditionally, UV-filters are categorized as either chemical or physical. The big difference is supposed to be that chemical agents absorb UV-light while physical agents reflect it like a bunch of mini umbrellas on top of the skin. While this categorization is easy and logical it turns out it's not true. A recent, 2016 study shows that inorganic sunscreens work mostly by absorption, just like chemical filters, and only a little bit by reflection (they do reflect the light in the visible spectrum, but mostly absorb in the UV spectrum).
Anyway, it doesn't matter if it reflects or absorbs, Titanium Dioxide is a pretty awesome sunscreen agent for two main reasons: it gives a nice broad spectrum coverage and it's highly stable. Its protection is very good between 290 - 350 nm (UVB and UVA II range), and less good at 350-400 nm (UVA I) range. Regular sized Titanium Dioxide also has a great safety profile, it's non-irritating and is pretty much free from any health concerns (like estrogenic effect worries with some chemical filters).
The disadvantage of Titanium Dioxide is that it's not cosmetically elegant, meaning it's a white, "unspreadable" mess. Sunscreens containing Titanium Dioxide are often hard to spread on the skin and they leave a disturbing whitish tint. The cosmetic industry is, of course, really trying to solve this problem and the best solution so far is using nanoparticles. The itsy-bitsy Nano-sized particles improve both spreadability and reduce the whitish tint a lot, but unfortunately, it also introduces new health concerns.
The main concern with nanoparticles is that they are so tiny that they are absorbed into the skin more than we want them (ideally sunscreen should remain on the surface of the skin). Once absorbed they might form unwanted complexes with proteins and they might promote the formation of evil free radicals. But do not panic, these are concerns under investigation. A 2009 review article about the safety of nanoparticles summarizes this, "to date, in-vivo and in-vitro studies have not demonstrated percutaneous penetration of nanosized particles in titanium dioxide and zinc oxide sunscreens". The English translation is, so far it looks like sunscreens with nanoparticles do stay on the surface of the skin where they should be.
All in all, Titanium Dioxide is a famous sunscreen agent and for good reason, it gives broad spectrum UV protection (best at UVB and UVA II), it's highly stable, and it has a good safety profile. It's definitely one of the best UV-filter agents we have today, especially in the US where new-generation Tinosorb filters are not (yet) approved.
When it comes to sunscreen agents, Zinc Oxide is pretty much in a league of its own. It's a physical (or inorganic) sunscreen that has a lot in common with fellow inorganic sunscreen Titanium Dioxide (TiO2) but a couple of things make it superior even to TiO2.
If physical sunscreens don't tell you anything, go ahead and read about the basics here. Most of what we wrote about Titanium Dioxide is also true for Zinc Oxide so we will focus here on the differences.
The first main difference is that while TiO2 gives a nice broad spectrum protection, Zinc Oxide has an even nicer and even broader spectrum protection. It protects against UVB, UVA II, and UVA I almost uniformly, and is considered to be the broadest range sunscreen available today.
It's also highly stable and non-irritating. So much so that Zinc Oxide also counts as a skin protectant and anti-irritant. It's also often used to treat skin irritations such as diaper rash.
As for the disadvantages, Zinc Oxide is also not cosmetically elegant. It leaves a disturbing whitish tint on the skin, although, according to a 2000 research paper by Dr. Pinnell, it's slightly less white than TiO2. Still, it's white and disturbing enough to use Zinc Oxide nanoparticles more and more often.
We wrote more about nanoparticles and the concerns around them here, but the gist is that if nanoparticles were absorbed into the skin that would be a reason for legitimate health concerns. But luckily, so far research shows that sunscreen nanoparticles are not absorbed but remain on the surface of the skin or in the uppermost (dead) layer of the skin. This seems to be true even if the skin is damaged, for example, sunburnt.
All in all, if you've found a Zinc Oxide sunscreen that you are happy to use every single day, that's fantastic and we suggest you stick with it. It's definitely one of the best, or probably even the best option out there for sun protection available worldwide.
Good old water, aka H2O. The most common skincare ingredient of all. You can usually find it right in the very first spot of the ingredient list, meaning it’s the biggest thing out of all the stuff that makes up the product.
It’s mainly a solvent for ingredients that do not like to dissolve in oils but rather in water.
Once inside the skin, it hydrates, but not from the outside - putting pure water on the skin (hello long baths!) is drying.
One more thing: the water used in cosmetics is purified and deionized (it means that almost all of the mineral ions inside it is removed). Like this, the products can stay more stable over time.
An often used emollient with a light and silky feel. It's very mild to both skin and eyes and spreads nicely and easily. It's often used in sunscreens as it's also an excellent solvent for sunscreen agents.
A clear, colorless, very easily spreadable and very volatile (evaporates from the skin easily) silicone fluid. It leaves a non-greasy, dry-smooth feel on the skin.
Probably the cheapest and most common silicone of all. It is a polymer (created from repeating subunits) molecule and has different molecular weight and thus different viscosity versions from water-light to thick liquid.
As for skincare, it makes the skin silky smooth, creates a subtle gloss and forms a protective barrier (aka occlusive). Also, works well to fill in fine lines and wrinkles and give skin a plump look (of course that is only temporary, but still, it's nice). There are also scar treatment gels out there using dimethicone as their base ingredient. It helps to soften scars and increase their elasticity.
As for hair care, it is a non-volatile silicone meaning that it stays on the hair rather than evaporates from it and smoothes the hair like no other thing. Depending on your hair type, it can be a bit difficult to wash out and might cause some build-up (btw, this is not true to all silicones, only the non-volatile types).
A film-forming polymer (big molecule from repeated subunits) to create water-resistant sunscreen formulas. It also improves the SPF value of sunscreen formulas (approx. 11-18% boost in SPF per 1% Styrene/Acrylates Copolymer).
A white powdery thing that's the major component of glass and sand. In cosmetics, it’s often in products that are supposed to keep your skin matte as it has great oil-absorbing abilities. It’s also used as a helper ingredient to thicken up products or suspend insoluble particles.
A silicone emulsifier that helps water and silicone oils to mix nicely together.
We don't have description for this ingredient yet.
It's one of the active parts of Chamomile that contains about 30% of bisabolol. It's a clear oily fluid that is used in skincare as a nice anti-inflammatory and soothing ingredient.
A helper ingredient that is used as a bulking and viscosity controlling agent.
It can also be used as a heat generating agent in water-less formulas as it has an instant heat-generating chemical reaction with water.
It’s a handy multi-tasking ingredient that gives the skin a nice, soft feel. At the same time, it also boosts the effectiveness of other preservatives, such as the nowadays super commonly used phenoxyethanol.
The blend of these two (caprylyl glycol + phenoxyethanol) is called Optiphen, which not only helps to keep your cosmetics free from nasty things for a long time but also gives a good feel to the finished product. It's a popular duo.
A controversial preservative that has formaldehyde-releasing properties. It works great against bacteria and also has mild fungicide abilities.
Cosmetic chemist, Colin wrote a great article about formaldehyde and DMDM Hydantoin. He writes that formaldehyde is the perfect example of "the dose makes the poison" principle. It's a natural stuff that can also be found in fresh fruits and vegetables, and eating it in tiny amounts is totally ok. However, in larger amounts (according to Wikipedia 30 mL of a solution containing 37% formaldehyde) it's deadly.
The amount of formaldehyde used in cosmetics either neat or through formaldehyde-releasing preservatives is tiny. Probably that is why the Cosmetic Ingredient Review Broad concluded both in 1988 and in 2008 that DMDM Hydantoin is "safe as used in cosmetics".
However, Colins argues that in the case of formaldehyde-releasing preservatives, formaldehyde is released slowly and the skin has probably not evolved to deal with that. The lingering formaldehyde might be toxic to the Langerhans Cells that are important for the skin's defense system. Another potential issue is that formaldehyde-releasers might also release other things while reacting with amino acids in the skin that is probably the explanation why some people are not allergic to formaldehyde but are allergic to formaldehyde-releasing preservatives. These are all theories, far from proven facts, but we feel that there are some justified reasons why formaldehyde-releasing preservatives and Dmdm Hydantoin count as controversial.
All in all, it's up to you to decide if you wanna avoid this preservative group or not. If so, there are other, less risky and more skin-friendly options out there.
A clear, light yellow liquid that is used to coat pigments (such as inorganic sunscreen agents or colorants) in cosmetic products. The coating helps to stabilize pigments in the formulas and also helps them to spread easily and evenly on the skin.
It's the acronym for Butylated Hydroxy Toluene. It's a common synthetic antioxidant that's used as a preservative.
There is some controversy around BHT. It's not a new ingredient, it has been used both as a food and cosmetics additive since the 1970s. Plenty of studies tried to examine if it's a carcinogen or not. This Truth in Aging article details the situation and also writes that all these studies examine BHT when taken orally.
As for cosmetics, the CIR (Cosmetic Ingredient Review) concluded that the amount of BHT used in cosmetic products is low (usually around 0.01-0.1%), it does not penetrate skin far enough to be absorbed into the bloodstream and it is safe to use in cosmetics.
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|irritancy, com.||0, 1|
|what‑it‑does||emollient | antimicrobial/antibacterial|
|irritancy, com.||0, 1|
|what‑it‑does||viscosity controlling | abrasive/scrub|
|what‑it‑does||emulsifying | surfactant/cleansing|
|what‑it‑does||emulsifying | surfactant/cleansing|
|what‑it‑does||moisturizer/humectant | emollient|
|what‑it‑does||antioxidant | preservative|