What Should I Consider When Buying Sunscreen?

Sunscreen is a skin care product made by using the principle of sun protection to protect the skin from ultraviolet rays, thereby avoiding the production and accumulation of melanin, and is applied on the skin to prevent the sun from contacting the skin.

Sunscreen

The main difference between sunscreen and sunscreen is in physical properties. Creams generally have a water content of about 60% and look more "thick" and paste-like; while emulsions with a water content of more than 70% appear to be relatively thin, there are fluidity.

Generally speaking, emulsions are more refreshing than creams because the water content is higher, but formulators can still use different oily ingredients and thickeners to adjust the "greasy" degree of creams. Therefore, you still need to look at the product itself.

Chinese name: Sunscreen
Use: Block UV

Principle: Reflects and scatters UV radiation
Ingredients: Inorganic substances such as zinc oxide and titanium oxide

Sunscreen Sun Protection Principle

Inorganic sunscreen ingredients are usually inorganic substances such as zinc oxide and titanium oxide, which can reflect and scatter ultraviolet radiation. Organic sunscreen ingredients are usually OMC (octyl methoxycinnamate) and oxybenzone. They can absorb ultraviolet radiation and convert radiant energy Converted into thermal energy. Many sunscreens also protect the skin from two types of ultraviolet rays (UVA, UVB). UVA and UVB cause different damage to the skin. In addition to cosmetic problems, UV rays can cause more problems, the most serious of which is skin cancer. From another perspective: It works through two mechanisms of reflection and absorption of light. In general, the inorganic substance has a reflection effect, and the organic substance has an absorption effect. The most common UV chemical absorber is PABA (para-aminobenzoic acid), which absorbs UVB. If your skin is sensitive, you should use sunscreen containing PABA with caution, as PABA can easily cause redness and allergies on sensitive skin. Other organic substances that absorb ultraviolet rays are: cinnamic acid (Cinnamates), which absorbs UVB; benzophenones (Benzophenones), which absorbs UVA; anthranilic acid or lipids (Anthranilates), which absorb UVA and UVB at the same time.

Sunscreen Sun Protection Reasons

Sunlight is one of the basic elements of human survival and health, but it can also cause many acute and chronic injuries to the skin.The wavelengths involved are mainly UVB (290-320nm) and UVA (320-400nm) .UVA is divided into long-wave UVA1 (340- 400nm) and short-wave UVA2 (320-340nm). UVB mainly causes acute damage such as sunburn, and long-term damage such as skin tumors, which can directly damage cell DNA and proteins. ^[1] Although UVA is not directly absorbed by biological target molecules, it can still significantly damage cell and tissue functions. Different wavelengths of ultraviolet light penetrate the skin at different depths. UVC is reflected and absorbed by the stratum corneum, and only a small part penetrates into the superficial layer of the epidermis. However, as UVC passes through the atmosphere, it is mostly absorbed by the ozone layer and cannot reach the earth's surface, so it will not cause harm to human skin. UVB is also mostly absorbed by the epidermis, and a small part reaches the superficial dermis, which is the main band of skin damage. It is carcinogenic but can be blocked by thick clouds, clothing and glass. A small portion of UVA is absorbed by the epidermis, and most of it penetrates the dermis, reaching deep into the middle of the dermis. UVA reaches 100 times more than the surface of the earth at noon in summer. UVA can penetrate the epidermis to the dermis and cause dermal damage, so it is the main ultraviolet pathogenic spectrum.

Sunscreen sunscreen classification

Sunscreen Physical Sunscreen

Using the principles of physics, the atomic particles of this sunscreen product are flakes. When spread on the face, it acts like a mirror to reflect sunlight to achieve the purpose of sunscreen. Both titanium dioxide and zinc oxide are physical sunscreen ingredients. They can form a protective film on the skin so that ultraviolet rays cannot penetrate the skin surface. Both can provide comprehensive UVB protection. Among them, zinc oxide can block UVA more. Typical physical sunscreen ingredients are white, pasty, and turn blue when exposed to water. However, this type of product also has certain limitations: for people with darker skin tones, their polish may be less natural; for people with dry skin, it is not moisturizing; not suitable for full body sunscreen; must use makeup removers to help Remove clean, etc.

Sunscreen Chemical Sunscreen

It is the use of chemical ingredients to protect the sun. This sunscreen uses the principle of absorption to protect the sun. It is a light-transmitting substance that absorbs ultraviolet light and converts it into molecular vibrational energy or heat to achieve sunscreen effects. Its derivatives, cinnamic acid, etc. When applied to the face, the atoms absorb sunlight to prevent it from touching the skin. Theoretically, physical sunscreen is better than chemical sunscreen, but most of the market is chemical sunscreen.

Classification of sunscreen sunscreen

Sunscreens are mainly divided into natural sunscreens, UV shielding agents, UV absorbers and new sunscreens. Natural sunscreens have the functions of absorbing, reflecting, and scattering harmful light, and have a repairing effect on the human body after sun exposure. They are derived from plants, animals, and minerals. ^[2] New sunscreens include physical sunscreens and bionic sunscreens.

How to use sunscreen

1. When the sun is weak and the exposure time is short: clean the skin first; use lotion; if it is dry skin, apply a little lotion appropriately; rub the sunscreen around SPF15.

2. When the sun is strong and the sun is exposed for a long time, in addition to the above steps, you must rub sunscreen with SPF 15 or more, and apply sunscreen powder every two hours.

3. When applying sunscreen, do not ignore the neck, chin, ears and other parts, being careful to cause uneven skin tone.

4. If the sweat has washed away the sunscreen, apply it again every few hours.

5. Even if sun protection measures are in place, if the sun is very strong, it is best to use after-sun care products at night.

Sunscreen purchase tips

1. Choose a refreshing sunscreen. When choosing, it is best to try it on the inside of your wrist. If the skin becomes red, swollen, painful, or itchy within 10 minutes, it means that you have an allergic reaction to the product. You can try it. This product with a sun protection index multiples lower, if you still have allergic reactions, you can only give up choosing this brand of sunscreen.

2. Choose a refreshing sunscreen. In addition to recognizing the OilFree (non-grease) logo on the outer packaging, it is also important to master some small identification skills. The selected sunscreen product can be applied lightly on the back of the hand or the tiger's mouth. If the skin can be absorbed quickly, there is no stickiness, whitening, and there is no glossy oily feeling, and it feels refreshing and moist, it can basically be regarded as Qualified refreshing sunscreen.

3. Due to the difference in oil secretion, the skin quality will change, so you should do another skin quality test. Oily skin should choose strong foaming cleansing products and strong penetration of water-based sunscreen products; dry skin should choose milky cleansing products and cream-like sunscreen products; neutral skin has a wider choice. Emulsion and spray sunscreens are basically suitable for all skin types.

4. For people with oily skin and prone to acne, you should choose a refreshing and non-greasy emulsion-like product. Do not use sunscreen and sunscreen products such as barrier creams. Pay special attention to whether the product is labeled non-comedogenic. (Meaning no acne).

5. If you have taken antihypertensive drugs, weight loss drugs, or sedatives, you should use sunscreens with higher sun protection factor. Since those who take this medicine are prone to skin allergy, it is necessary to increase the sun protection factor.

6. When choosing sunscreen, you must consider your own skin quality, whether it is allergic to skin, and sensitive skin should choose some plant types and relatively mild sunscreen, and pay attention to hydration after sun care.

Sunscreen purchase parameters

When buying sunscreen, pay attention to two indicators, one is SPF (Sun Protection Factor), the sun protection index; the other is water resistance. SPF is designed based on the effect of sunscreen on UVB. Although a high SPF value means longer protection against UVB, it does not mean that it has the same effect on UVA. If you need to protect UVA and UVB at the same time, you should consider buying a "broad spectrum" sunscreen; the water resistance of sunscreens is getting more and more attention. Because sweat, sea water, swimming pool water, etc. are all problems we face. For outdoor sports and travel enthusiasts, the water resistance of sunscreen is very important. According to the American Academy of Dermatology, an SPF value can protect the skin from sunlight in the sun for 10 minutes, so a sunscreen with an SPF of 15 can protect us for 150 minutes. Don't save as much as using eye cream with sunscreen. Use larger amounts each time. Use sunscreen 30 minutes before going out to the sun (in the water) to allow the active ingredients to fully penetrate the face.

Sunscreen milk contraindications

1. The higher the SPF value, the longer the sun protection time

Generally, the skin of yellow people can withstand strong light for 15 minutes without being burned, so the SPF15 UV protection products can resist about 225 minutes of strong ultraviolet radiation. SPF5-8 sunscreen products can be used for daily care, shopping and shopping, and SPF10-15 sunscreen products can be used when going out. Use SPF20-30 waterproof sunscreen when swimming or sunbathing. When the exposure time exceeds the effective sun protection time, it should be applied in time.

2.SPF value cannot be accumulated

Apply two layers of SPF10 sunscreen, only one layer of SPF10 protection effect.

3. Do not go out before applying sunscreen (cream)

Sunscreens, like normal skincare products, take time to work (sunscreens don't need to be absorbed). So apply it 10-20 minutes before going out.

4. Sunscreen (cream) is not effective when applied, but must reach a certain amount to exert its effect

Generally, sunscreen can achieve the sun protection effect when it is applied on the skin at 2 mg per square centimeter.

5. People with different skin types should choose different sunscreen products

Oily skin should choose a water-based sunscreen with strong penetration; dry skin should choose a creamy sunscreen; neutral skin is generally not strictly regulated.

6. Sunscreen (cream) should not be used before applying makeup. It should be applied after using skincare products.

Sunscreen use misunderstanding

Long-wave UVA can penetrate deep into the subcutaneous tissue, destroy skin collagen and elastic fiber tissue, cause skin to produce wrinkles and melanin, and even skin cancer. UVA has a strong penetrating power and can penetrate clouds and glass. ^[3] Therefore, you should apply sunscreen in the office, but you can choose those with light texture or sunscreen. You can also choose a sunscreen with maintenance function. Generally, SPF15 / PA + is sufficient. It should be emphasized that sunscreen or barrier cream cannot block computer radiation. The most important way to eliminate radiation is to do a good job of cleaning every night.

Sunscreens often see the letters "PA". Science has confirmed that UVA-1 is the killer of skin aging, so Japanese scientists have developed sunscreens that specifically resist UVA-1, and use "+" to indicate defense strength. PA's correct statement is Protection of UVA-1. Its degree is marked by three strengths: +, ++, +++. The more "+" characters, the better the effect of preventing UVA-1.

SPF30 + is a product that is higher than SPF30, which is mainly from a new rule of the Ministry of Health in 2003: In order to prevent the behavior of SPF value from rising blindly, all sunscreen products above SPF30 are not marked with a specific sunscreen value, and SPF30 + It means that the products that passed the inspection before the release of this regulation still maintain the original labeling method. Therefore, it is best to consult the counter staff before purchasing such products.

Generally, if there is no special label on the sunscreen, the body and face can be used universally. But if you are going to play in the water, you really need to use sunscreen specially prepared for the body-it is waterproof and sweat-proof, and it is not easy to wash off, and such products are not suitable for face use.

If you are an office worker from 9 to 5 and need light makeup, sunscreen foundation is a convenient choice and makeup is easy. If you do nt like foundation and want to moderately improve skin tone, sunscreen with a slight touch-up function Cream can meet your needs; if you are in a place where you don't need any makeup at all, or if you are exposed to strong sunlight during the day, it is best to use a sunscreen with an appropriate index. As for the difference between sunscreen and sunblock, the main reason is that the barrier cream generally has the effect of correcting skin tone, and it helps the foundation to apply makeup more easily.

You know that sun protection is a science. Many girls know how to apply sunscreen, but they often apply a layer after layer of sunscreen directly to their faces, and as a result, they may "make up" for horrible fat particles! We tell you a few tips for sun protection: After makeup, you can use a paper towel to gently wipe off sweat and oil, or just use oil-absorbing paper to remove oil, and then use sunscreen powder to make up; if your face is sweaty and oily Many, then make sure to wipe off sweat and greasy with makeup remover wipes first, and then apply sunscreen, or use a moisturizing spray to clean the face before repairing.

Use the mask immediately after sun exposure, as a result, sensitive skin such as rashes have appeared. This is because the skin after drying is very dehydrated and has some inflammatory reactions, so when you apply an acidic whitening mask on your face, it is equivalent to increasing the chance of causing sensitivity. The correct method is to use a hydrating mask immediately after sun exposure. It is especially recommended to use a gel-like or paper-film hydrating mask. It is better to freeze in the refrigerator if conditions permit. After drying, the dehydrated skin will be cooled and hydrated, and it will naturally restore the health of the stratum corneum. As for the whitening procedure, it is not too late to use after the skin is completely stable.

Clouds provide almost no isolation to UVA rays. All UVA rays can penetrate the clouds, which means that 90% of the UV rays can penetrate the clouds, except for the thick cumulonimbus clouds when it is dark. In order to block some ultraviolet rays, it is best to use SPF10-15 products in cloudy weather.

The skin will turn brown after sun exposure, which indicates that the skin has entered a state of self-protection-the thickening of the skin and the production of melanin are manifestations of skin self-protection. However, melanin can only partially absorb ultraviolet UVB, which acts as an isolation and protects the skin from damage. However, it does not have the function of absorbing ultraviolet UVA. Therefore, even tanned skin will also be damaged by UVA and sun protection is also required.

After-sun care is best done on the day of the sun or even at that time. The earlier the time, the less the skin will be damaged. Sunlight will cause the skin to lose a lot of moisture and cause the skin epidermis to be rough, so "moisturizing and calming" is the focus of care after sun exposure. If you can do the post-sun care in the first time after sun exposure, it will not only reduce the redness and scorching reaction of the skin, but also help to reduce the damage of ultraviolet rays. Ice cubes, cold showers, and hydrating gels are great ways to care after the sun.

The principle of sunscreen is to isolate the skin from ultraviolet rays. Since the isolating ingredients must penetrate into the horny surface to exert a long-term absorption and isolation effect, it must be wiped 20 minutes before going out and replenished before going out. The effect is good; at the dosage, at least 1-2ml each time to achieve the best isolation effect; and should try to avoid going out during the strongest period of sunshine (10 am to 2 pm); Also make good use of various auxiliary supplies.