Spf 50 Sunscreen Lotion
Salt & Stone Spf 50 Sunscreen LotionIngredients explained
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.
A light emollient ester (C8-10 fatty acids connected to C12-18 fatty alcohols) that absorbs quickly and leaves a dry but silky finish on the skin. In terms of skin feel, it is similar to Dicaprylyl Carbonate, another commonly used light emollient.
A plant based ingredient that helps water to mix with oil (aka W/O emulsifier). It's especially good for soft to low-viscosity water-in-oil emulsions with non-greasy, pleasant skin feel like lip balms or thick body butters.
A liquid fatty acid created from oleic acid. It's claimed to have great odour, thermal and oxidation stability and is great for the stabilization of pigments and mineral particles in oils and solvents. It's quite popular in foundations.
A super common emollient that makes your skin feel nice and smooth. It comes from coconut oil and glycerin, it’s light-textured, clear, odorless and non-greasy. It’s a nice ingredient that just feels good on the skin, is super well tolerated by every skin type and easy to formulate with. No wonder it’s popular.
Probably the 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 super common, medium-spreading emollient ester that gives richness to the formula and a mild feel during rubout. It can be a replacement for mineral oil and is often combined with other emollients to achieve different sensorial properties.
Butylene glycol, or let’s just call it BG, is a multi-tasking colorless, syrupy liquid. It’s a great pick for creating a nice feeling product.
BG’s main job is usually to be a solvent for the other ingredients. Other tasks include helping the product to absorb faster and deeper into the skin (penetration enhancer), making the product spread nicely over the skin (slip agent), and attracting water (humectant) into the skin.
It’s an ingredient whose safety hasn’t been questioned so far by anyone (at least not that we know about). BG is approved by Ecocert and is also used enthusiastically in natural products. BTW, it’s also a food additive.
PEG-30 Dipolyhydroxystearate is a popular water-in-oil (w/o) emulsifier, meaning that it helps the oily and watery parts of the formula to mix in a way where water droplets are dispersed in the continuous oil phase and not the other way round.
Compared to the more commonly used oil-in-water (o/w) emulsions, w/o emulsions tend to be heavier and less cosmetically elegant, but PEG-30 Dipolyhydroxystearate is claimed to help with this and enables a light and elegant skin feel. It also has a molecular structure that creates large anchors both in the water and in the oil phase making the resulting emulsion not only cosmetically elegant but also very stable.
It's the yellow, solid stuff that you probably know from beeswax candles. It's a natural material produced by honey bees to build their honeycomb.
As for skincare, it's used as an emollient and thickening agent. It's super common in lip balms and lipsticks.
- A natural moisturizer that’s also in our skin
- A super common, safe, effective and cheap molecule used for more than 50 years
- Not only a simple moisturizer but knows much more: keeps the skin lipids between our skin cells in a healthy (liquid crystal) state, protects against irritation, helps to restore barrier
- Effective from as low as 3% with even more benefits for dry skin at higher concentrations up to 20-40%
- High-glycerin moisturizers are awesome for treating severely dry skin
Polyethylene is the most common plastic in the world. It is a super versatile polymer (molecule from repeated subunits) and when it comes to cosmetics, it is often referred to as microbeads. Well, it used to be referred to as microbeads, as it was banned in 2015 in the " Microbead-Free Waters Act" due to the small plastic spheres accumulating in the waters and looking like food to fish. Well done by Obama.
But being versatile means that polyethylene does not only come as scrub particles but also as a white wax. In its wax-form, it is still well, alive and pretty popular. It thickens up water-free formulas, increases hardness and raises the melting point of emulsions and water-less balms. It is particularly common in cleansing balms and stick-type makeup products due to its ability to add body, hardness and slip to these formulas.
The oil coming from the seeds of dog-rose, a wild rose species native to Europe, northwest Africa and western Asia. It's a nice emollient, moisturizing plant oil loaded with skin-nourishing fatty acids (linoleic acid - 51%, linolenic acid - 19% and oleic acid - 20%).
If you start to dig a bit deeper into the rosehip oil topic, you will soon see that there are lots of species of rose, and it's all a bit confusing to know what the differences and similarities between the oils of the different roses are. As far as our research can tell, here is the gist.
In skincare two major types of rosehip oil are used:
1. Rosa Rubiginosa that is a synonym for Rosa Eglanteria and for Rosa Mosqueta. We will call it RR from now on.
2. Rosa Canina, or RC
The oil content and composition of RR and RC is similar, but there are some differences: RR contains 8% of oil, while RC contains a bit more, 10%. However, the quality of RR oil seems to be a bit better: it contains 78% essential unsaturated fatty acids while RC contains only 71%. Also, the linoleic-oleic ratio of RR is better (3.3 vs 2.5) that might be important if your skin is acne-prone (as linoleic acid is good for acne and oleic is not).
There is one more important thing to mention: RR oil is famous for containing the miracle active, tretinoin. Though Wikipedia puts RR and RC oil under the same article called as Rose hip seed oil, the referenced research about tretinoin content examines only Rosa Rubiginosa. We looked for a research paper explicitly stating that Rosa Canina also contains tretinoin, but could not find one, so we can neither deny nor confirm it. What we could find is a paper mentioning the tocopherols (vitamin E) and carotenoids (pro-vitamin A) content of Rosa Canina oil that gives it some nice antioxidant properties.
All in all, it is a great emollient plant oil with great fatty acids beneficial for any skin type.
The oil coming from the pulp of one of the most nutritious fruits in the world, the avocado. It's loaded with the nourishing and moisturizing fatty acid, oleic (70%) and contains some others including palmitic (10%) and linoleic acid (8%). It also contains a bunch of minerals and vitamins A, E and D.
Avocado oil has extraordinary skin penetration abilities and can nourish different skin layers. It's a very rich, highly moisturizing emollient oil that makes the skin smooth and nourished. Thanks to its vitamin E content it also has some antioxidant properties. As a high-oleic plant oil, it is recommended for dry skin.
- It’s naturally in our skin and behaves there like a sponge
- It can bind up to 1000 times its own weight in water
- It is a big molecule from repeated subunits (polymer) so different molecular weight versions exist (unfortunately there is no way to determine MW from INCI list only)
- High-molecular-weight-HA (>500 kDa) is an excellent surface hydrator, skin protectant and can act as an osmotic pump helping water-soluble actives to penetrate deeper into the skin
- Low-molecular-weight-HA (< 500 kDa) can hydrate the skin somewhat deeper though it is still a big molecule and works mainly in the epidermis (outer layer of the skin)
- Low-molecular-weight-HA might also help the skin to repair itself by increasing its self-defense (~ 200kDa used in the study)
- Ultra-low-molecular-weight-HA (<50kDa) is a controversial ingredient and might work as a pro-inflammatory signal molecule
If you have spotted ethylhexylglycerin on the ingredient list, most probably you will see there also the current IT-preservative, phenoxyethanol. They are good friends because ethylhexylglycerin can boost the effectiveness of phenoxyethanol (and other preservatives) and as an added bonus it feels nice on the skin too.
Also, it's an effective deodorant and a medium spreading emollient.
It’s pretty much the current IT-preservative. It’s safe and gentle, but even more importantly, it’s not a feared-by-everyone-mostly-without-scientific-reason paraben.
It’s not something new: it was introduced around 1950 and today it can be used up to 1% worldwide. It can be found in nature - in green tea - but the version used in cosmetics is synthetic.
Other than having a good safety profile and being quite gentle to the skin it has some other advantages too. It can be used in many types of formulations as it has great thermal stability (can be heated up to 85°C) and works on a wide range of pH levels (ph 3-10).
It’s often used together with ethylhexylglycerin as it nicely improves the preservative activity of phenoxyethanol.
The attachment of glycerin and oleic acid that works mainly as a co-emulsifier and stabilizer to create stable water-oil mixes, aka emulsions. It is also popular in cleansing products as it helps to thicken them up and has some refatting and skin-smoothing effect.
It's one of the most commonly used thickeners and emulsion stabilizers. If the product is too runny, a little xanthan gum will make it more gel-like. Used alone, it can make the formula sticky and it is a good team player so it is usually combined with other thickeners and so-called rheology modifiers (helper ingredients that adjust the flow and thus the feel of the formula). The typical use level of Xantha Gum is below 1%, it is usually in the 0.1-0.5% range.
Btw, Xanthan gum is all natural, a chain of sugar molecules (polysaccharide) produced from individual sugar molecules (glucose and sucrose) via fermentation. It’s approved by Ecocert and also used in the food industry (E415).
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|irritancy, com.||0, 1|
|what‑it‑does||emulsifying | viscosity controlling|
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|irritancy, com.||0, 2-4|
|what‑it‑does||moisturizer/humectant | solvent|
|irritancy, com.||0, 1|
|what‑it‑does||emollient | viscosity controlling | emulsifying | perfuming|
|irritancy, com.||0, 0-2|
|what‑it‑does||skin-identical ingredient | moisturizer/humectant|
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|what‑it‑does||skin-identical ingredient | moisturizer/humectant|
|what‑it‑does||emollient | emulsifying | perfuming|