A-Closer-Look-At: Sunscreens (part I)

Sunscreens – part one: How do sunscreens work?

The big question is of course, why should you use sunscreen. Sunscreen is good for preventing sunburn. The red color of sunburned skin is a tell-tale sign that skin cells are damaged. Damage can be induced by UVA (Ultra violet sub type A) and UVB (Ultra Violet sub type B). There is also UVC (Ultra Violet sub type C), but the ozone layer prevents UVC from entering the atmosphere. UVB increases melanin production in the skin, which makes us tan, and also causes sunburn.

UVA is perhaps even more dangerous. UVA is able to penetrate deeply into the skin, ages skin quickly and damages DNA. Damaged DNA can lead to cancer (okay, I have to admit, that the fact that ‘DNA damage causes cancer’ is a very, very brief summary about what causes cancer. Even now, scientists are still trying to figure out how and why cancer exists.)

UVA isn’t blocked by glass or the clouds. Unlike UVB, UVA doesn’t give you any warning signs. You’re not going to get a sunburn or a tan. UVA is present every day, in every season, whether it is overcast or not. My first advice would be  to wear sunscreen (with at least SPF 15) every day. My second advice is to wear a broad spectrum sunscreen which protects you for both UVB and UVA. You should be able to tell from the packaging if this is the case.l

Oh, and it is wise to avoid sunbeds, according to a study in 2007, even one visit to a sunbed can increase your chances of getting skincancer (melanoma, the most dangerous kind) by 19%! (International Agency for Research on Cancer Working Group on artificial ultraviolet (UV) light and skin cancer. The association of use of sunbeds with cutaneous malignant melanoma and other skin canacers: A systematic review. Int J Cancer. 2007: 120: 1116-1122.)

How do sunscreens work?
There are two types of sun filters; chemical and physical.
Chemical filters (oxybenzone, octyl methoxycinnamate, octocrylene and avobenzone) are absorbed into the skin and absorb UV radiation. A number of chemical filters can be absorbed by the body and end up in the bloodstream. Others can generate free radicals (free radicals are bad!) when they react with the suns rays and therefore cause skin damage. This also happens if you don’t use a sunscreen!

Physical sunfilters stay on the skin and reflect the light. Good examples are titanium oxide and zinc oxide. They create a barrier to protect the skin by not allowing harmful chemicals to enter the bloodstream. They are known to not cause irritation. A drawback is that physical sunscreens leave a white film on the skin. If these sunscreens don´t leave a white film, nanotechnology is used.

What is nanotechnology?
Nanotechnology is the use of very, very tiny particles to enhance the performance of a product. The name derives from a nanometer. A nanometer is one billionth of a metre. Nanotechnology is the study of manipulating material on a molecule or atom scale. It is a relatively new study, so long term health effects are not known yet. The main concern is whether or not the particles can be absorbed by the skin and other cells of the body. This could lead to a higher dosage of the chemical in your body. The dosage of a chemical is linked to its toxicity. How higher the dosage, the more dangerous (poisonous) a chemical is. The main concern is if nanotechnology can penetrate the skin and cells. If yes, it could be dangerous, if not, we don´t have to worry. Unfortunatley, this is still being researched, so I can´t give a clear statement whether or not nanotechnology is advisable or not.

What is SPF?
SPF, sun protection factor is a (laboratory) logaritmic measure of how effective a sunfilter is. This is mentioned on the bottle. The SPF is the amount of UV radiation required to cause sunburn on skin with the sunscreen on in comparisation of the amount UV radiation required without the sunscreen.

It is said that the number of SPF determines how long one can stay in the sun without re-applying the product. For instance, if you get a sunburn from one hour of exposure to the sun, you should be able to stay in the sun for 15 hours with an SPF 15 on. This is not true. The intensity of radiation varies considerably with time of day. In early morning and late afternoon, the radiation has to pass through more of the atmosphere because the sun is nearer the horizon. The amount of SPF is determined by factors like skin type, the amount of sunscreen that is applied and the frequency of re-application, activities (sports, swimming) and the amount of sunscreen the skin has absorbed.

It is therefore recommended to re-apply sunscreen (half a teaspoon every application for the face and a shotglass for the rest of the body) every two hours and to stay out of the sun during the hottest hours of the day (12.00 – 15.00) of the day. Or go and have a nice long lunch in the shade. Or take a siesta.I mean, it’s vacation anyway.

Make up has an odd number of SPF (for instance, SPF 8 or 18) because first, the product is formulated and then the SPF is measured. Usually, an SPF in make up, or in a sunscreen in spray form isn´t as effective as a  regular SPF because you have to apply the sunscreen thickly. With a spray, it is usually not easy to determine where, how thickly and evenly the sunscreen is applied. With make up it is the same way. To get the SPF that is indicated on a foundation or powder, you have to put on the foundation very thickly (a.k.a. cakey!). So it’s always better to use a sunscreen under your day cream and makeup.

SPF can’t be increased by layering it. I will explain this with an experiment. Take two glasses. Fill them with water. Add to each glass the same amount of food coloring (or dye), for instance, 3 drops. Mix well, and take half of the first glass. Put this in a new glass. Now take half of the other glass, and put it in the third glass as well. Has the color changed? No. So, if you use a daycream with SPF 15 and a foundation with SPF 15, you will not get SPF 30. It will only help you to reach the required half teaspoon of sunscreen.

As I said earlier, SPF is a logaritmic scale. This means that SPF stops 93% of the UV rays (UVA or B depending on the sunscreen). Factor 30 stops 97% of the radiation. A higher factor is not always better. The higher the SPF, the more greasy the product will feel like. If your skin type is average (meaning not extremely fair), I would recommend sticking with SPF 15 in the winter and SPF 30 in the summer.

A wee bit extra
Next to a good sunfilter, it is also wise to check the rest of the sunscreen. Are there irritating ingredients in the sunscreen, like perfume, PABA, coloring agents, methylisothiazolinone, tea tree oil, witch hazel, ylang ylang, mint or citrus? Alcohol is not good either, unless it is a fatty alcohol (just type in the name of the Alcohol in wikipedia, and scan the page on the word “fatty alcohol”. For instance, cetearyl alcohol is a fatty alcohol).

And last, but no means least, after tanning/staying in the sun and using a sunscreen, hydrate your skin! Take a luke warm shower or apply aloe vera to cool the skin. Or use after-sun.

In the next post about sunscreens, I will talk about different kinds of sunscreens, and which ones to look out for!

Until next time,
Dymphy

A-Closer-Look-At: Ethyl Alcohol aka Ethanol

Ethyl alcohol, also known as ethanolpure alcoholgrain alcohol, or drinking alcohol. In this article I will refer to it as ethanol, because that is the term I personally use the most.

I love, love, love to use ethanol in disinfection. I do a lab study and before and after, we have to clean/disinfect your work space. I usually spray some ethanol on the surface and wipe it off with a paper cloth. I have to wait a minute (or a few minutes if I used to much), during which time I get my supplies and voilà, a clean and sanitzed space. A tip: do wait at least 10 minutes before lighting any flame – not that I have any weird accidents with it, but just to be safe. I personally would recommend sanitizing with ethanol for non-plastic surfaces and testing a little patch before spraying it all over.

Ethanol is made by the fermentation of sugar by bacteria or by the hydration of ethylene (the adding of a hydrogen atom). I know for sure that the ethanol used in beer is made by the fermentation of sugar. Actually, the reason why some beers are stronger than others, depends on the bacteria culture and the amount of sugar added. Until the sugar runs out, the bacteria produces ethanol, or until the amount of ethanol is too high for the bacteria to survive in.

Because of hydroxide (the oxygen and hydrogen atoms, the characterizing group of any alcohol), ethanol can form hydrogen bridges with water molecules, helping dissolve organic compounds, such as sugars or parts of the celwall of bacteria. If you want to sanitize, keep in mind that a concentration of 70% or higher is to be used. Below that concentration, the ethanol isn’t effective enough. So, disinfecting with beer (5-10%) or wine (15%) is not really smart. Absinthe (70%) and Neutral grain spirit (90%) are somewhat better, but it’s still better to use regular ethanol (available in 70% or 96%) which can be found at drugstores or pharmacies. I’m alo guessing that Absinthe and Grain spirit do not need any preservative.

Oh, and, according to my old chemisttry teacher, 100% pure alcohol is a myth. Even if you attempt (as a chemist) to obtain a mixture of 100%, pure alcohol, it will disintegrate. 96% is the highest concentration of ethanol possible.

Ethanol can also be found in skin care. If it’s at the top of an ingredien tlist, (as in the first 5 ingredients) it can irritate the skin, but if it’s at the end of an ingredient list, the concentration isn’t considered a problem. High concentrations of alcohol can be found in most products for oily or skin with acne. The alcohol dehydrates the skin, making the skin produce more sebum, causing it to become more oily and clog the pores even more.

To sum it all up, ethanol is great for sanitizing, but not so good for the skin. And if you want to use ethanol for sanitizing, a concentration of 70-96% works best.

Until next time,

Dymphy

A-Closer-Look-At: Argan Oil

Argan Oil is hot at the moment, in the sense that it is trendy to use it
And why not? Celebrities like Beyonce are said to use Argan Oil. It is a deep, golden colored oil and is a very multi-functional product. Argan oil can be used as a skin- and hand serum and as bathing oil. It can be used by all skin-types from greasy to super dry, flaky skin types like myself. I’ve been using argan oil in the evening as a serum under my regular night cream and it’s wonderful! Flakes disappeared in a few days and the oil gave my skin a natural glow. Argan oil originates from Morrocco, where it was first used as an oil for cooking and baking. Later, it was also used for skin and hair.

Argan oil is extracted from the seeds of the Argania Spinoza tree. The argan tree grows in infertile and dry regions of south-west Morrocco. From June to September, the fruits are harvested and processed into oil.

A single tree produces about 30 kilos of argan fruit, which in turn yields 700 ml of argan oil. Until a few years ago, the seeds of the argan tree were found in goat droppings, since they were the only ones able to climb up the thorny trunk.

Nowdays, the demand is much higher and so the fallen fruits of the argan tree are collected.
The fruits are then taken to the villages to be processed.The seeds are beaten with rocks to get  the kernel out.

The fruit is used to feed livestock and the shells are used to make the fire which is needed in the extraction of the oil.

If the oil is used for consumption, the kernels are roasted before pressing to add some flavor.

After cooling down, the nuts are ground by hand. Water is added during the grinding process, so a paste will be formed. The paste is pressed by hand and what’s left is pure argan oil.

 

This labour intensive process takes about 15 hours, which makes argan oil pretty expensive.

Nowdays, this process is more and more replaced by mechanical press machines to extract argan oil. The collection and removal of the outer shell of the seed is still done by hand, but everything else is done by a machine. This saves time and eliminates the use of water, thus prolonging the shelf life of the oil.

Argan oil contains twice the amount of vitamin E found in olive oil, an anti-oxidant. It also contains a lot of lipids and fatty acids which are beneficial for the skin, including oleic acid, palmitic acid, and especially linoleic acid. It is therefore great for people with acne, as well as eczema and psoriasis.

Until next time,

Dymphy

A-Closer-Look-At: Polymers & Plastics

Polymers & Plastics

Although I already explained polymers briefly in the article on methyl methacrylate and poly(methyl methacrylate), I wanted to write a more in depth explanation of polymers.

Aw, look at my old science notes. Brings back memories. 😉

Polymers are the result of a polymerization reaction. I think the best way to explain this is with Lego. Within Lego, you have different building bricks. You have white bricks, blue bricks, red bricks, yellow bricks and so forth. You have bricks with four studs on them, and bricks with six or eight studs. If you take a brick, and place it onto the next, you are building a column. Building with Lego has a lot of similiarities to a polymerization reaction. You have individual units of small molecules, which you can bond to each other.

I have only seen two major polymerization reactions (I’m a biologist, not a chemist, so excuse me if I exclude some possibilities) in cosmetic science. The first one is the formation of the most common polymer, by the breaking a double bond. A double bond can be found in a molecule (a brick), mostly between two carbon atoms. Oxygen is also known to form double bonds (other atoms as well).

As shown in the figure above, carbon atoms (and also oxygen atoms) are going to form a double bond to make sure to get the necessary 4 (carbon) or 2 (oxygen) bonds. In a polymerization reaction, another molecule is present to which a carbon atom can bond. The double bond breaks and both carbon atoms form the fourth bond with another molecule.

A polymer can consists of a large number (10.000+) of molecules, hence the ~ sign on both ends. Another polymerization reaction is shown in the photo of my old science journal above, when a hydroxyde (OH, also known as the ‘alcohol’ group) reacts with another hydrogen atom and thus forms water (H2O). The carbon atom then bonds with the other oxygen atom and a polymer is formed.

Polymers are considered plastics and are used in cosmetics as thickening or film forming (for instance in nailpolish) agents. If you find a plastic or a polymer in a ingredientlist, please do not flush it through the sink. The plastic ends up in the ocean, where it can contribute to the plastic soup that already is floating around there, killing sea animals by choking or contributing to the malformation of a sea animal. Rinse the product off with a make up removal wipe or by using a cotton pad and some cleanser.

I hope the topic of polymers and plastics is even clearer now. If not, just ask a question in the comments.

Until next time,

Dymphy

A-Closer-Look-At: Cetearyl Alcohol

Many people cringe when they see alcohol on an ingredientlist. And they should, because the alcohol/hydroxy group dries out the skin. The hydroxy group that makes alcohol an alcohol, consists of both an oxygen (symbol: O) and a hydrogen (H) atom. A hydroxy group can form a hydrogen “bridge” with another water molecule. It basically pulls out water and takes it with it when you, for instance, wash it off your face.

But why is cetearyl alcohol (or cetostearyl alcohol/cetylstearyl alcohol) good for the skin? That is because of it’s fatty acid tail. The tail usually has an even number of carbon atoms, ranging mostly from 8 to 22 carbon atoms, although 36 or more aren’t an exception.

To be more precise, Cetearyl Alcohol is a mixture of fatty alcohols, of which cetyl and stearyl alcohols make up most of this ingredient. Since cetearyl alcohol has a polar, (water loving) head and a non-polar (oil loving) head, it is a surfactant. It can therefore be used as an emulsifier, stabilizer, opacifying agent (cetearyl alcohol turns into a white, waxy solid at room temperature) and a foam boosting agent.

Cetearyl alcohol was first extracted from whale oil, but since commercial whaling is forbidden, cetearyl alcohol is now produced from vegetable oils, like palm or coconut oil. It is also an end-product of the petroleum industry. It can also be made synthetically, from, for instance, breaking up triglycerides (three fatty alcohols bound together). The source can determine the amount of carbon atoms. For instance, rapeseed produces longer molecules of about 20 tot 22 carbon atoms, whilst coconut oil will yield molecules with 12 to 14 carbon atoms.

Please be careful if you have sensitive skin, cetearyl alcohol can possibly worsten dermatitis.. If you don’t have dermatitis, cetearyl alcohol is a very safe to use moisturizer and surfactant.

Until next time,
Dymphy

A-Closer-Look-At: Glycerin

Glycerin, also known als Glycerine and Glycerol, is a colorless, odorless, viscous and sweet-tasting liquid. It has a low toxicity and three hydroxyl (=the main group of alcohol, very water-soluable) groups. It can occur as the polar head of a fatty acid. It can be made from natural substances by hydrolysis of fats and by fermentation of sugars. Next to extraction, glycerin can also be made synthetically and it is a by-product of making soap.
A plus is that the glycerin is skin-identical; it means that it can be found naturally in skin. It is therefore one of the many substances in skin that help maintain the outer barrier and preven dryness and scaling.

Glycerin is mostly used in cosmetics to moisturize, giving the skin a smooth feel, as a thickener and as lubricant. It can also be used as a humectant because glycerin likes to absorb moisture.

 

From the dermis, the water is drawn out to the epidermis by the glycerin. The more glycerin, the more water is pulled out of the under layers of the skin. It is therefore not very wise to apply pure glycerin to your skin. It can even cause blisters if left on too long. Since the water drawn from the inner layers can evaporate into the air, glycerin is mosty combined with other moisturizers, oils and/or other film-forming ingredients.

If you are a pro-amateur (a non-make up artist who want professional materials and results) and you are wondering if a mixing medium is something for you, you can try out this DIY. Take one part glycerin and three parts (boiled, then completely cooled before adding) water. Mix well. You can mix it in a bottle, or in a jar. Keep in mind that it doesn’t contain preservatives so you should only make a little at a time. This DIY should keep well for two weeks, discard any left overs. You can also make enough for just one application.

I hope you enjoyed this information and the little DIY on the end.

Until next time,

Dymphy

A-Closer-Look-At: Bismuth Oxychloride and why it causes breakouts

Tanistates wonders in her recent article about the Ben Nye foundation and concealer why some of her foundations oxidize and why bismuth oxychloride causes break outs. I went out, did some research and found the answer plus some tips to prevent oxidizing.

What is bismuth oxychloride?
Bismuth oxycloride is a pigment that is composed of bismuth (a metal), oxygen and chloride. It is very rare in nature, and is mostly synthetically made. It is a crystal, but ground up it is a white, almost pearlescent powder. It can be found in many cosmetics, such as the so claimed “mineral makeup”, foundations and (pressed) powders. It is mostly used as a skin protective, thickener and absorbent agent. It adheres well to the skin.

Why does it cause break outs?
Bismuth oxychloride has a unique, cube like (for lack of a better word) crystalline structure. One of the corners of that cube can scrape, poke and thus irritate your skin. It also can get stuck in pores. And we all know, clogged pores can result in break outs.

Why do some foundations oxidize?
Oxidation is a process in which (in the case of foundation) the components react with the sebum (the oils in your skin). In the process, electrons are “freed”, which causes a ingredient in the foundation, mostly a metal or an oxide to oxidize. The extra electrons alter that ingredient, causing a color change. An extreme example (gotta love extreme examples) is Iron. There are two main Irons, Fe2+ and Fe3+. Fe is the abbreviation of Iron, while the number before the plus stands for the amount of free electrones. Fe2+ is light green, and Fe3+ is light yellow.

Helping the oxidation process along is the pH, the level of acidity of your skin. If you have a very acid skin (with low pH), you might experience more oxidation. Why? The optimum (= the best place/time/etc.) pH for oxidation is well, acidic.

How could I prevent oxidation?
There are a few tips and tricks to prevent oxidation:

1) Always ask for a small sample before you buy a certain foundation, or let a saleslady apply it and wait for a few hours before you purchase the foundation.
2) Moisturize well before applying a foundation to prevent the skin from secreting excess sebum.
3) Apply a primer. Not only it will help to make your foundation last longer, but it will form a barrier, so that the sebum can’t interact with the foundation.
4) Experiment. Every body is different. Try what works. Switch food (eat healthier, for instance, soda makes your body more acid), try different moisturizers/toners/primers.
5) Try a lighter foundation. If you really like the formula, try one or two shades lighter and after the oxidation, you might have the right match. Or try to set your foundation with a powder lighter than your skintone.
6) Avoid foundations which are oil-based, and read the ingredientlabels. Scan for ingredients that contains oxide or metal, and pick a foundation that contains as few metals or oxides as possible.

I hope this helps!

Until next time,

Dymphy