Have you ever showered with a shower gel that gives such silky feeling that you don’t want to ever leave? Well, silicones are responsible for this feeling. Also silicones can be found in most primers. They are ˝guilty˝ for the smooth effect and we can’t blame them. #sorrynotsorry

What are silicones ?

Silicones are synthetic organic polymers of silicon. They can form silicones, silicates, silanes, or siloxanes. These can connect to larger molecules, which are normally flexible.

  Chemical structure State of matter
1. Silicone oils (dimethicones, cyclomethicone…) Liquids
2. Silicone waxes (alyildimethicones) Resins
3. Silicone emulsifiers (silicone polyether) Elastomers (dimethicones)

Approximately 85% of all silicones in cosmetic products are classified as silicone oils. That’s why we’ll give them a little more attention.

Silicone oils

Dimethicones

Dimethicones are waterproof ingredients, that distribute well over surfaces and are inert (they don’t react with other compounds). In one of the studies, more than 60 different dimethicones were observed to see which one is most common in cosmetic products. The most commonly found are dimethicone/vinyl dimethicone crospolymer (in 457 cosmetic products) and dimethicone crospolymer, which was present in 442 products.

Cyclomethycones

Cyclomethycones are volatile compounds, but they don’t leave a cold feeling while evaporating as ethanol does. They are odorless and non-toxic. Usually they are used as solvents or carrier systems for other silicones. With their incorporation into lipsticks, we can prolong their persistence.

Silicone waxes

Alkyldimethicones

Alkyldimethicones improve the compatibility of ingredients with oils and increase the stability of cosmetic products containing silicones. They work as moisturizers as well. They are used in many cosmetic products such as lipsticks, creams and lotions. They are very welcomed in suncreens since they are able to increase their effectivness.

When can we use silicones?

Silicones are safe and compatible (aren’t complicated and can get used to the new environment quickly). They are excellent ointments and lubricants, antifoams, emulsifiers, emollients and surfactants. Almost everything, right? But recently they are not that ˝in˝ anymore, since almost every package has a ˝without silicones˝ inscription.

Where can we use them?

Silicones are very common in decorative cosmetics and in skin care products. They are also found in products for children and products for sensitive skin, because they don’t irritate the skin. They are also suitable for application to deeper skin layers. Their origin isn’t animal so they are also suitable for vegans.

1. Hair: accelerated drying, increased shine, easier combing, regeneration

2. Give a good sensory feeling on the skin

3. Moisturizing (formation of a film that can beathe)

4. Skin protection (waterproof)

5. Cleaning ability (silicone powder – the ability to absorb lipophilic substances, including sebum)

6. Increase the effectiveness of active ingredients

7. Matting effect (for oily skin products, since silicones aren’t comedogenic)

8. Adhesion of pigments (used in primers under our make-up)

What are their advantages?

Silicones can get very well distributed and well smeared. They are surface-active (surfactants) substances that are colorless, tastless and odorless. Absence of color, taste and smell is very important in the formulation of cosmetics. They are inactive, temperaturely and chemically stable (they don’t interact with other substances).

Studies show that silicones are very safe for the consumer. They belong to the “Clean Beauty” substances. Clean Beauty is a platform where you can find safe products, they can be made of natural or synthetic materials. The point is, they are safe for the user.

Myths about silicones

“Silicones are toxic to nature because they rinse into rivers and seas.”

Health Canada has concluded that cyclomethicone (a type of silicone) has a low or no probability of environmental pollution and there is no necesity for any restrictions about the use of this substance. Very volatile silicones quickly evaporate and degrade in the air under the influence of the sun. Smaller quantities that remain in solid or liquid state are hydrolysed.

“We inhale silicones inhale and can be loaded in the lungs.”

Approximately 95-99% of the particles in sprays are bigger than 10 μm. According to the study, the particles inhabited by mistake are located and remain in the nasal cavity. They don’t go anywhere, regardless of the amount of silicones we inhale. So the chances of inhaling silicones, which can get and stay in the lungs is equal to almost 0.

“Silicones can clogg the pores.”

Silicones as substances aren’t occlusive (we still know what that means, right?), So they can’t clog the pores. They help to protect our epidermis and are also allowing our barrier to “breathe”. There are no reports proving that silicones irritate our skin, they actually do all the contrary, the feeling they leave is very ligh and soft.

However, due to the whole chaos, they are looking for alternative forms. Substances that are recently replacing silicones are olive oil derivatives, argan oil derivatives, coconut derivatives, alternatives to silicone elastomers, wheat sprouts.

In one study, however, it was confirmed that silicones pass the skin barrier and are loaded into epidermis. It’s expected to have negative effects on the epidermis, which we can see as a reduction of it. However, the whole study is imprecise, as they didn’t specify which parameters they took into consideration, so it’s difficult to be sure about the relevancy of this study.

Conclusion

If you are still afraid that the use of cosmetic products with silicone will clogg the pores, don’t worry, it won’t. Whether silicone compounds cross the skin barrier or not we know that such large compounds don’t cross neither healthy or damaged skin. Silicones have many advantages, even though they aren’t natural.

We already opened the shorts season, when travelling in Sicily and Morroco. And by this we opened the season of hairless legs. Hairs have their purpose to protect us from mechanical and thermal effects of the environment. But nowadays because of the impacts of the society and aesthetical reasons we remove the hair with several different depilation and epilation techniques.

Let’s get to know our hairs!

On our body there are two types of hair: fluffy and terminal. Terminal hairs are longer (more than 1mm), thicker, more pigmented, usually there is one hair for pilosebaceous unit and have longer life cycle. Fluffy hairs are shorter, thinner, there are more hairs growing in a pilosebaceous unit, are non pigmented and have a shorter life cycle.

Phases of hair growth

Hairs go through 3 different phases. First is anagen phase or phase of growth, that lasts approximately 6-8 years and depends on gender, age and health. Second is catagen phase or phase of transition – in this phase the growth in hair bulb starts shutting down and slowly stops. Last is the telogen phase is which the hair dies off, the hair bulb moves towards the surface and the hair falls out. When the last phase elapses, new cycle begins.

Photography: Neja Stojnič

Methods of hair removal

We know depilation and epilation techniques. And many people use this two terms wrong. With the term depilation we always think off removing hair with the wax, but this is wrong.

Depilation methods remove hairs without the effect on a hair bulb, the effect of depilation lasts around two weeks. Under the term depilation we count shaving and chemical depilation.

Epilation methods remove hair, including the bulb, the effect lasts around 6-8 weeks. Under term epilation we count waxing, pulling, laser methods and electrolysis.

Physical methods shaving, waxing, pulling hairs with tweezers, use of abrasives
Chemical methods chemical and enzymatic depilation

Shaving

We will not discuss this for long, like the effect of the shaving doesn’t last long (maybe 3 days). Shaving is the most popular method, because it’s fast, simple, cheap and the least painful. Hairs are removed only from the skin surface.

Shaving accelerates hair growth and makes them thicker.

Photography: Neja Stojnić

Waxing

Waxing counts as a epilation method. The effect last around 6-8 weeks.Waxing does not accelerate hair growth. For this methods hairs need to be at least 3mm long. It is unsuitable for diabetics and patients with vascular diseases. It can also cause some side effects like folliculitis, hyperpigmentation and scars.

Ingredients in waxing cosmetic products are usually: resin, bees wax, paraffinum, camphor, local anesthetics and ingredients with antibacterial effect.

Hot waxing is the process, where we heat up the wax and then apply it on the skin so it surrounds the hairs so they become a part of the wax. We remove the wax in the opposite direction of the hair growth. In cold waxing there is no need to heat up the wax.

Chemical methods of hair removal

Hair removing runs with chemical compounds and enzymes. The procedure happens without pain and it’s effects are visible for 2 weeks. Chemical compound penetrates in the hair cortex, where the reduction of disulphide bond in keratin happens. Simply, this means that the bonds that hold the hair together splits and this causes the hair to fall out. Hairs are removed on the skin surface or little underneath.

Active ingredients for hair removal
Active ingredientPropertiesSide effects
Sulfide (barium sulfide)– most effective
– strong unpleasant smell
Toxic for the skin, hair grows back into the skin
Sulfite– less irritation and absence of the strong smell
– ineffective
/
Mercaptans– methyl, butyl, benzyl-mercaptane have very strong smell
– less smell from polar mercaptans (tiolactic acid, tioglycolic acid) – slower but safer
Skin irritation, inflammation, chemical burns, scars
Photography: Neja Stojnić

Cosmetic products for depilation based on thioglycolates

First ever patented depilatory creams were based on thioglycolates and until today they still present a standard for chemical depilation. Most commonly used it calcium thioglycolate in combination with calcium hydroxide. A reversible reaction happens between hair keratin and alkaline thioglycolate. Depilation effect happens after 5-15min, pH rises above 10. These compounds are safe in concentrations up to 15%, show low systemic toxicity and are stable (in concentrations between 2,5-5%).

Side effects may be: skin irritation, inflammation, chemical burns and scars.

Laser hair removal

Discovery that lasers unspecifically destroy hair follicles was made more than 60 years ago. Laser enables selective photothermolysis – hair removal without damaging the surrounding tissue.

How does a laser work?

Exact certain wavelength of light and the duration of laser pulse leads to thermal damage of target tissue, that contains a chromophore. Melanin in hair follicle absorbs the laser light. Laser energy in the form of a light transforms into heat, that causes selective destruction of a hair follicle.

With this procedure the final destruction can be done to the hairs, that are in the moment of procedure in growth phase (5-15% of all body hairs), that’s why this procedure needs to be repeated (5-8 repetitions).

Nd:YAG laser

This laser can have a continuous source of light or pulse with wavelength of 1064nm. Melanin badly absorbs light with wavelength as high as this, that’s why this laser is ineffectual for permanent hair removal. Fast warming causes photomechanical damage to melanocytes in a hair bulb, wherein there is no damage done to the hair follicle. This is the safest and most efficient laser for dark skin (type IV). It only causes the delay of hair growth not the permanent removal.

Effectiveness of laser hair removal

One treatment only delays the hair growth for a short period of time. Before the treatment hairs need to be removed with shaving. While doing the treatments with the laser you should avoid exposure to the sun. Laser is the most effective on light skin with dark hairs, and not so effective with light or blonde hairs.

Fotografija: Neja Stojnić

IPL technology

IPL regulates the spectre of light with wavelength from 550nm to 1200nm with filters and so adjusts considering the skin phototype and hair color. More treatments lead to permanent hair removal. At IPL technology the light effects all the skin surface, not only hair follicles like the laser does. Because of this fact the risk of skin damage is higher with IPL. Effectiveness of IPL compared to laser is lower, because the energy is more scattered and is not concentrated just on the hair.

Nanoparticles are one of the latest threats to humankind. Almost. Certainly not in cosmetics. Nanoparticles don’t exist from yesterday, they have been here for quite some time. Only science, that studies them – nanotechnology is relatively new.

What are nanoparticles?

Nanoparticles are small units of material, that is smaller than 100nm. We know that nanometer is 10⁻⁹ right? Nanoparticles can come from a different origin: natural (desert dust), unintentionally produced (burning out biomass and fossil fuel), engineer (sunscreens and other cosmetics, textile).

Photography: Neja Stojnić

Why do we even use nanoparticles?

Nanoparticles exhibit new properties and functions of already known materials. This properties are very different than the properties from the same ingredients, but bigger order of size. Not only in cosmetics, but also in food technology and medicine they show a lot of advantages.

  • they stabilize and protect ingredients and extend the time of usage (fatty acids in oil, vitamins and antioxidants)
  • they affect  solubility and speed of solution of the ingredients
  • better activity on the skin
  • higher effectiveness and tolerance of UV filters
  • delivering cosmetic active ingredients in deeper layers of the skin

But everyone says, that nanoparticles are bad,..

Every good invention has a bad side, right? Nanoparticles can be toxic. Toxicity can be a consequence of damaging effects of decomposed products from nanoparticles. Physical properties of nano sized particles (big surface, charge), regardless the chemism of the products that compose nanoparticles, can be a reason for toxicity as well. Nanoparticles show unique physical-chemical properties because of their size. They can be more chemically reactive and can express higher biological activity.

Photography: Neja Stojnić
The connection between nanoparticles and unwanted effects

In the last few years the exposure to nanoparticles has risen because of development of different techonologies. Scientists have figured out, that this leads to a lot of unwanted effects on your health system. Connection was made between nanoparticles in the environment and unwanted effects of respiratory tract and cardiovascular system.

Special physical-chemical properties of nanomaterials lead to forming reactive oxygen species in cells. Reactive oxygen species (ROS) cause oxidative stress. Cells react to this kind of stress with inflammation. Research on rodents had shown that empty nanoparticles have a much higher inflammation effect on the unit of mass than bigger particles with the same chemism.

Inhalation of nanoparticles leads to loading in the lungs, they can also enter the bloodstream and brains. That’s why their use is forbidden in aerosols.

Now before you panic, close your computer and throw all of your sunscreens with nanoparticles away

Nanoparticles don’t work like that when applied to the skin. Our epidermis provides effective protection from effects of the environment. They can pass through the cells, hair follicles or sweat glands. But they don’t pass healthy skin. Damaged skin is another story, in this case the particles can pass the skin, but under what conditions remains unknown.

Why are mineral UV filters in sunscreens in nano size?

Mineral filters in their normal size (200-400nm for zinc oxide and 150-300nm for titanium dioxide) disperse really badly and because of that the application is difficult. They reflect and scatter the light and that causes an unwanted white layer on the skin surface. With the help of nanotechnology we are able to reduce the size of the parcticles under 100nm. With doing that we achieve easier application and transparency.

Photography: Neja Stojnić

Do nanoparticles cross the skin – main subject of scientists

There are a lot of arguments between scientists whether nano sized particles pass the skin barrier and what are the effects of penetrating into the deeper layers. Some studies prove them passing the skin and their toxic effects on the cells, while others disprove this theory.

There are many differences depending on the sort of the vehicle in which we include nanoparticles. Researches had shown that nanoparticles in mineral oil did not pass the skin, while the ones included in O/W emulsion (oil in water – usual for all the creams) did penetrate. Penetration was much higher in the area with a lot of hairs, which shows the penetration through the pores and hair glands.

The smaller the particles, the bigger the chance that they will penetrate the skin. There is a big difference between a particle that is 2nm big and particle that is 50nm big. As we mentioned before, the smaller the particles, the bigger the chance that their properties will change.

Does a regulative on cosmetic field protect us?

We’ll be honest, not really. Cosmetic producers are not obligated to tell what size of  nanoparticles are included in their products. They are obligated to write ‘’NANO’’ next to the filter that is in nano size, but whether this means particles 2nm or 100nm large no one knows, except them.

They represent a big progress in cosmetic industry

Usage of nanometer delivery vehicles is the future. Until now all the cosmetic products contained highly effective ingredients, that manufacturers bragged about. But whether this ingredient will achieve the wanted target in the skin was another thing. Only molecules smaller than 500Da can penetrate in the skin. And if we include a peptide with a molecular mass of 4000Da in our products, it will most certainly not penetrate in the skin. Nano delivery vehicles enable reducing these big molecules into smaller ones, so they can be included to the systems that will reach the target area. This delivery systems are liposomes, dendrimers, solid lipid nanoparticles,..

What is your opinion on nanoparticles in cosmetics?

Always when you look at a cosmetic product, ingredients must be written somewhere. The description of these ingredients is based on the INCI list. If INCI isn’t available the name can be based on the chemical name of the ingredient.

Ingredients of cosmetic products must be listed on the decreasing order of weight. But only if their content in the product is bigger than 1%. If it’s smaller, the ingredients can be listed by pure chance.

But we cannot use all the ingredients randomly. There is a Regulation on cosmetic products. This Regulation consists of:

1. Report on the safety of the cosmetic product

2. Annex of prohibited substances (Annex II)

3. Annex with restricted substances: pigments, preservatives, UV filters (Annexes III – VI)

The substances we pay special attention to are: ingredients with restrictions, nanomaterials and CMR substances (hormonal interrupter). Why? Because this is the only way to ensure that cosmetic products are safe for the consumer. We have a lot to say about nanomaterials.

Photography: Neja Stojnić

We want to clear something out. Animal testing has been banned since 2013. When writing the Safety Report on Cosmetic Products, researches done before 2013 and tested on animals, can be used. But there cannot be any new animal testing. Instead of animal testing, alternative methods have been introduced, which are slowly replacing animal testing. But the truth is that all this is prohibited in the EU. If we order a product from another continent where these restrictions are different, no one can guarantee us that the product has not been tested on animals. Because it can’t be controlled.

From theory to practice

We will now look at some examples. Almost all preservatives that are allowed in cosmetic products have certain limitations. We know what the preservatives are, right?

So, the easiest way to “understand” INCI is to know the restrictions of a particular substance. The exact percentage of a substance doesn’t have to be given. But what we want to know is at least the approximation of that percentage.

Let’s look at the structure of the cream containing vitamin C. If we buy a cream containing vitamin C, we want some effect, right? But if the percentage is too low, there will be no effect.

Aqua, Isoamyl P-Methoxycinnamate, Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, Aloe barbadensis leaf juice, Glycerin, Gyceryl Stearate, Phenoxyethanol, Acrylates / C10-30 Alkyl Acrylate Crosspolymer, Sodium Stearoyl Glutamate, 3-0-Ethyl Ascorbic Acid, Xanthan Gum, Tocopherol , Sodium hydroxide, Hexyl cinnamal, Linalool, Limonene, CI 15510, Citronellol, Benzyl Salicylate, Potassium Sorbate, Sodium Benzoate, Geraniol, Sodium Chloride, Sodium Sulfate, CI, Fragrance, Sodium Citrate, Ethylhexylglycerine, Sodium Hyaluronate, Panthenol, Crystalline Ethylenediamine Disuccinate 14700

So, we can find a preservative in the INCI list. In our case, this is phenoxyethanol, the concentration of which is limited to max 1% in the Regulation. As you can see, vitamin C (ethyl ascorbic acid) is listed after phenoxyethanol, which means that this product contains less than 1% of vitamin C.

Aqua, Isoamyl P-Methoxycinnamate, Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, Aloe barbadensis leaf juice, Glycerin, 3-0-Ethyl Ascorbic Acid, Gyceryl Stearate, Phenoxyethanol, Acrylates / C10-30 Alkyl Acrylate Crosspolymer, Sodium Stearoyl Glutamate, Xanthan Gum, Tocopherol , Sodium hydroxide, Hexyl cinnamal, Linalool, Limonene, CI 15510, Citronellol, Benzyl Salicylate, Potassium Sorbate, Sodium Benzoate, Geraniol, Sodium Chloride, Sodium Sulfate, CI, Fragrance, Sodium Citrate, Ethylhexylglycerine, Sodium Hyaluronate, Panthenol, Crystalline Ethylenediamine Disuccinate 14700

Well, this looks a bit better. In this case, we can look at other substances with restrictions. For example UV filters. Methoxy cinnamate and triazine are limited to a maximum concentration of 10%. Phenoxyethanol is found after vitamin C (ascorbic acid). That usually means that this product contains more vitamin C than in the example above, but not necessarily. Since there is no rule dictating whether there need to be written the exact concentrations of the ingredients, we can only assume about the real concentrations in the products.

Some more useful web pages, if you ever find yourself in a dead end

Most verifying website for substances in cosmetic products is called CosIng. What can we find on this site?

1. All the names of the substances (chemical, INCI, other possible names)

2. Restrictions, if there are any (there is an attachment, where all restrictions are written)

3. What’s the function of the substance in the products

4. The SCCS opinion (we have already discussed this, in the case of parabens, which have been said to have carcinogenic affects – the committee has checked all the studies and limited the percentage so that the use is safe now)

SCCS = group (committee) of independent experts writing opinions on ˝problematic˝ substances.

There is also Rapex, where we can find all products containing any prohibited substances. If the product is in the Rapex system, it’s immediately removed from the market. The company may change product’s composition (they replace the problematic substance with another) and then the product has a ˝second try˝ on the market.

Yes, in cosmetic industry it’s all limited just approximately. But still, we can manage this ˝chaos˝ more or less. It’s not the easiest, but it’s the most effective. Hopefully, the next time you will be experts on checking the composition of your cosmetic products and you will be able to decide whether you are being misleaded or not.

We’ve already gone through basics about UV rays, protection against UV rays and everyday use of sunscreen. Now it’s time to take a look in the world of compounds that protect us from UV rays – UV filters.

There are two types of UV filters

Organic or chemical and inorganic or physical UV filters. Physical filters scatter and reflect UV rays, while chemical filters absorb them. Physical filters leave a white residue (unless they are nano size), while chemical filters spread quite smoothly.

Sunscreens are usually a mixture of different chemical and physical filters, because with combining them we achieve a broad spectrum protection.

There are even more UV filters then we mentioned in a previous post, so we asked members of a Slovenian Facebook group Ljubim kozmetike to mark the most common filters in their sunscreens. We are going to describe 4 most common ones.

Organic UV filters

Data from studies shows, that organic filters are present in most sunscreens on the market. The most common organic filter is Ethylhexyl methoxycinnamate, since it is present in 80% of all sunscreens. Chemical filters easily absorb in the skin and reach blood circulation. Consequently they can load in different tissues, liver and brain.

Ethylhexyl methoxycinnamate

Oktyl metoxycinnamate (OMC) is a UVB filter known as 2-ethylhexyl-4-metoxycinnamate. As a compound it is allowed for usage in cosmetic products in United States and Europe in concentrations between 7.5-10%. Lots of studies suggest that OMC in an endocrine disruptor, because it can affect excretion of hormones.

After applying of cream with 10% concentration of OMC on the whole body (40g), the filter was absorbed in the skin and was later found in urine and blood. But if we take the highest measured concentration, the complete concentration in 4.7L of blood was only 0.002%.

The positive side of this filter is that it does not irritate the skin and does not cause sensibilisation.

Ethylhexyl salicylate or oktyl salicylate

It’s a organic UVB filter, that absorbs the UV rays. It is allowed for usage in cosmetic products in concentrations up to 5%. This is a filter with relatively good safety profile. Ethylhexyl salicylate possesses an ability to stabilize other photolabile (sensitive to light) UV filters and make them longer lasting. Quite a guy, ha?

This filter has a really low toxic profile. It does not cause irritation or sensibilization, it is not phototoxic and does not cause foto-allergies.

Inorganic UV filters

Inorganic filters used in sunscreens usually contain metal oxide particles, for example titanium dioxide and zinc oxide. These two can be used in concentrations up do 25%, but are usually contained in lower concentration – between 5-10%.

Chemical filters are still dominant in sun-protection products, but the number of products containing only physical filters is rising. One of the reasons why is the fact that they offer a broad spectrum protection – TiO₂ is more successful protection from UVB range, while ZnO is more successful at protection from UVA and UVB1 rays (the protection for UVB range is lower). Using these both filters together provides a broad spectrum protection. Another positive side of using physical filters is absence of irritation and limited skin penetration.

Zinc oxide

Dermal absorption is the main route of entrance for ZnO nanoparticles in our system. Most studies showed that ZnO particles don’t penetrate in deeper layers of the skin. Penetration is significantly higher when the skin barrier is damaged.

Titanium dioxide

Titanium dioxide is commonly used as a white pigment in colors, plastic and paper and as an additive in food. Nanoparticles of TiO₂ are used because of the capability to absorb the UV light in sunscreen products. TiO₂ particles have very low toxicity.

Nanoparticles of TiO₂ can be used in sunscreen products in concentrations up to 25%. Studies show that particles of this filter don’t penetrate healthy or damaged skin. In human keratinocytes it exhibited almost no cytotoxicity, which suggest a very small toxic potential on the skin level.

Exposure to UV filters

We are most exposed to UV filters in a dermal way. Suggested application of sunscreen is 2mg/cm² skin, so that we would reach the protection factor listed on the product. This means we would have to use the whole 40g cream to protect the whole body. At this amount of product, the maximum penetration would be 5% for some organic UV filters. Studies show that amount of product applied is much lower than suggested (less than half). So if we apply a product with SPF 50, the real protection will be probably 25 or less.

UV filters offer a protection from erythema, actinic keratosis and carcinoma. There is also data that sunscreens block normal synthesis of vitamin D and that they act as endocrine disruptors. But in normal usage this is not the case.

What can we conclude?

Usage of UV filters is questionable from aspect of safety. More and more studies show the link between bigger usage of sunscreen products and phenomenon of hormonal and growth disorders. At this point you need to realize that in studies they work with much higher concentrations than allowed. With cosmetic products it is impossible to come in touch with such high concentrations. But we can’t just ignore what the studies say, because side effects can occur within sensitive population. Effects of being exposed to low doses of UV filters for a long period of time are pretty much unknown. Scientists should investigate further and try to find safer compounds to protect us from UV rays.


Sunscreen is essential for preventing skin diseases and premature aging. In conclusion: sunscreen should be used in every season. However, experts started to warn about the importance of protection against UV, but that happened only a few years ago.

There are several types of electromagnetic radiation and one of them is UV radiation. Ultraviolet radiation consists of 3 wavelengths: UVA rays (emitting a wavelength from 320 to 400nm and aren’t absorbed by the ozone), UVB rays (the wavelength from 290 to 320nm, partially absorbed by ozone) and UVC rays (are stopped by ozone) -> well, what’s still left from ozone.

UV radiation has some beneficial effects, such as vitamin D synthesis. It also has a positive effects on the treatment of dermatological problems (acne, psoriasis), bone and joint disorders and childhood diseases. However, there are more negative effects (role in pathogenesis of skin cancer, photo-aging and photo-immunosuppression) than positive.

 UVAUVB
Acute effectsImmediate pigmentation, photosensibilisationErythema, edema, pigment darkening, thicker epidermis, synthesis of vitamin D
Chronic effectsPhoto-aging, immunotoxicityPhotocarcinogenesis, immunotoxicity

UVA rays

UVA rays represent the largest part of solar radiation. They stimulate the formation of reactive oxygen species or ROS. We’ve already been writing about it in blogs (Vitamin C and After 25th, we begin to grow old). UVA rays increase the number of inflammatory cells and reduce the activity of Langerhans cells, which are the first line of defense of our immune system.

UVB rays

UVB radiation causes sunburn. It represents about 18% of total solar radiation and it’s 50-100x stronger than UVA radiation. Our DNA molecules absorb UVB light very well, which can lead to mutation and carcinogenesis. They can damage biomolecules (proteins, lipids and DNA molecules).

UV rays don’t rest!

A few days ago, we’ve asked on Instagram story some questions about your habits regarding to sunscreens and their usage.

57% use the sunscreen only on the beach

56% prefer using sunscreen with a very high protection factor (50, 50+)

69% apply sunscreen several times a day

22% avoids nanoparticles in sunscreens

It’s a bit worrying that more than half of you use sunscreen only at the beach. It’s true that in winter the sun is significantly weaker comparing to summer, but this doesn’t necessarily mean there are no UV rays. In winter while it’s snowing it’s even more likely to get sunburned, because UV rays reflects from snow (white colour reflects sun rays). Despite the fact that there are clouds, who says UV rays can’t pass these clouds to get to us? Again, not so much, but they pass through. Have you ever heard of a friend who went hiking ant the weather was cloudy and came home as red as a beet? Because we have! So this means that UV rays exists even on a cloudy day.

Why is re-application necessary?

Probably, the ones who had answered that apply sunscreen only once, are asking themselves what the hell? You have applied the cream, okay. So you don’t sweat or touch your face? Consequently, by touching and sweating you remove the cream. Also, UV filters stop working after a certain amount of time, meaning they no longer have the effect of protection.

Sun protection products

The main purpose of sunscreens is to protect the skin against the harmful effects of UV radiation. But in order to achieve this effect, it takes more than just choosing the right UV filter in the appropriate concentration. One of the important things is also technological formulation and other ingredients which can support the effect of UV filter or can decompose it.

There is currently a flood of sunscreen products on the market. The SPFs are from 1-50 +. There are products with low protection (SPF 6-10), medium protection (SPF 15, 20, 25), high protection (SPF 30, 50) and very high protection (50+). According to European standards, UVA protection must represent at least 1/3 of the declared SPF.

Recently, we have seen the SPF mark on almost all face products, whether it’s decorative or nourishing. It is especially popular that UV filters are added to the powders, BB and CC creams.

What’s the problem of foundation with SPF15?

If you didn’t just come from the Stone Age, you probably know that for a SPF written on packaging, the application must be 2mg / cm². You probably don’t know how much of sunscreen that is. For a face it is supposed to be used 2 full fingers of cream. We are not 100% sure, but somewhere we’ve found that 70kg man has to use almost the whole sunscreen in order to achieve the SPF protection written on the packaging. Is this even possible? Not really.

Because of the incorrect or insufficient amount (usually 0.8 mg/cm²) of the sunscreen, the actual SPF on our skin is only 20 to 50% of SPF declared on the packaging. So, when using foundation with SPF15, we usually apply a pump or two. This means the actual SPF on the skin is probably barely 3, if not less.

SPF 30 vs. SPF 50

I think that most of us, who have been more or less introduced to the protection against UV rays, know this graph.

This graph shows us that with the protection factor 30, we achieve approximately 95% of protection against UVB rays. With a protection factor of 50, approximately 96.5% of protection. Experts are arguing whether this 1.5% makes a big difference. We must be aware of the amount of UV filters that must be incorporated into the product with SPF 50 comparing to SPF 30. This increased quantity may be unfavorable for people with photosensitivity disorders. If you don’t have them, it’s up to you, if you want to use higher or lower SPF. Keep in mind that you are likely to apply less product and the actual protection is lower.

Types of UV filters

Currently, two types of UV filters are in use, physical and chemical, both of them minimize the previously listed effects of exposure to UV radiation.

Physical or inorganic filters disperse and reflect UV rays while chemical or organic filters absorb them. More and more studies assess the role of these compounds in developmental and endocrine abnormalities, which have been demonstrated in animal and human studies.

Organic UV-absorbing filters are divided into: PABA derivates (PABA, ethylhexyldimethyl PABA), cinnamic acid derivates (ethylhexylmethoxycinnamate, octylmethoxycinnamate), salicylic acid derivates (homosalate), octocrylene, triazine derivates (ethylhexyl triazone), benzophenone derivates (oxybenzone BP-3), sulisobenzone) and dibenzoylmethane derivates.

Among the physical UV filters that reflect and disperse UV rays are zinc oxide and titanium dioxide. Sunscreens are mostly a mixture of several organic and physical UV filters, because with the combination we achieve broad spectrum protection.