Cosmetics that prevent skin from getting tanned and sunburned
Sunscreen refers to cosmetics that add a sunscreen agent that can block or absorb ultraviolet rays to prevent skin from being tanned and sunburned . According to the principle of sun protection, sunscreens can be divided into physical sunscreens and chemical sunscreens.
Sunscreens need to choose products with different SPF or PA values according to specific objects to achieve the purpose of sun protection. Sunscreens work by shielding the skin from UV rays. The main difference between sunscreen lotion and sunscreen lotion lies in the physical properties. The general water content of the cream is about 60 %, which looks "thick" and is in the form of a paste; while the lotion , with a water content of more than 70%, looks relatively thin and has fluidity. Lotions are generally lighter than creams because of the higher water content, but formulators can still adjust the "greasy" level of creams using different oily ingredients and thickeners. So, you still need to look at the product itsel
sun protection principle
Sunscreens act as sunscreens through inorganic and organic active ingredients, primarily to prevent sunburn , photoaging, and tanning.
Specifically, sunscreens that block ultraviolet rays generally refer to physical sunscreen ingredients. The principle is like wearing an umbrella and wearing a hat, which can reflect the ultraviolet rays irradiating the human body. The main ingredients are zinc oxide , titanium dioxide , and physical sunscreen powder 280- 370nm (protection against UVA), physical sunscreen powder 250-340nm (protection against UVB). UV-absorbing sunscreens generally refer to chemical sunscreen ingredients that can absorb the energy of UV rays and undergo chemical reactions. There are many types of chemical sunscreen ingredients, which are reserved for the introduction of UVA and UVB absorbers in the following ingredients column. "Prevent the skin from being tanned and sunburned" means that sunscreens must have the functions of protecting both UVA and UVB rays.
Sunscreens can be divided into physical sunscreens and chemical sunscreens. However, chemical sunscreens have better skin feel and visual effects, while those with sensitive or extremely dry skin are more suitable for physical sunscreens .
Use sunscreen particles to form a protective layer on the surface of the skin to reflect the light waves in the ultraviolet rays that may cause damage to the skin, so as to protect the skin. The particles of physical sunscreen generally stay on the surface of the skin and will not be absorbed by the skin, so the burden on the skin is relatively small, and it is not easy to cause skin sensitivity.
Through the combination of certain chemicals and cells, before the cells are damaged, the part of the ultraviolet rays that may cause damage to the skin is absorbed to achieve the purpose of sun protection.
The tiny particles in physical sunscreens are generally composed of titanium dioxide, zinc oxide, etc. For chemical sunscreens, salicylates, cinnamates, and anthranilates are considered to be relatively safe and non-irritating sunscreen ingredients.
The efficacy of sunscreens mainly depends on the SPF and PA values of sunscreens. The higher the SPF index, the longer the UV protection time will be, but it does not mean that the higher the SPF value, the stronger the protection.
Ideally, sunscreen should be applied after cleansing and before applying makeup to ensure that it adheres to the skin cells that need protection. But in practice, basically after the daily skin care steps are over, you can apply sunscreen, and then put on your daily makeup. But sunscreen, like general skin care products, takes a certain amount of time to be absorbed by the skin, so you should apply sunscreen 10 to 20 minutes before going out.
At the same time, it is important to note that the duration of the effect should be determined according to the SPF or PA value of the product.
Sunscreen should be applied to the neck, chest, arms, ears (the areas that are especially forgettable and especially prone to sunburn), and any other exposed areas.
(1) In principle, more sunscreens can be used.
(2) Use your fingertips to adjust the sunscreen first, and place it on the forehead hairline, forehead, ears, nose, cheeks, perioral, neck, neck, front of the neck, chest V area and The back of the hand, the extended side of the wrist, etc. For example, in summer, all light-exposed parts such as double forearms and calves should also be included to avoid omission.
(3) Gently spread the sunscreen on each part with your fingertips
(4) When a light-sensitive patient sees a doctor, the doctor should remind the patient to pay attention to the parts that are prone to omission
1. The application site
When applying sunscreen, don't ignore the neck, chin, ears, etc., to avoid uneven skin tone.
2. Cleaning products
Be sure to thoroughly remove sunscreen products every night, so don't rest and sleep with sunscreen on.
3. Use enough
Sunscreen is not effective when applied, but only when it reaches a certain amount. Usually, when the amount of sunscreen applied on the skin is 2 mg per square centimeter, the proper sunscreen effect can be achieved. It should be noted that the SPF value cannot be accumulated. Applying two layers of SPF10 sunscreen will only have the protective effect of one layer of SPF10.
4. Don’t mix sunscreens from different brands
Combining them can increase the likelihood of skin irritation . The ingredients of various brands of sunscreens are inconsistent. If they are mixed and overlapped on the skin, it may cause the ingredients to interfere with or repel each other, reduce the sunscreen efficacy, and even cause skin allergies.
5. Pay attention to saving
Sunscreens may be less effective if exposed to prolonged heat or direct sunlight. Do not use spoiled sunscreen cosmetics, as it not only reduces sun protection, but is more likely to irritate the skin.
6, pay attention to sunscreen dead corners
When applying ordinary sunscreen, the lip skin also needs to be careful. But if there is no instructions, or use sunscreen products for the eyes, do not use it on the skin around the eyes.
1. Use sunscreen cosmetics to avoid skin allergies.
2, choose the appropriate coefficient of sunscreen.
3. Use the right time: don't apply sunscreen before going out.
4. The SPF value cannot be accumulated. Applying two layers of SPF10 sunscreen will only have the protective effect of one layer of SPF10.
5. It is best not to mix and use different brands of sunscreen at the same time.
6. Do not reduce the effect due to improper storage.
7. Pay attention to sun protection when it is cloudy.
1. Skin test
It is recommended to do an accurate skin test before purchasing sunscreen. Oily skin should choose water-based sunscreens with strong penetration; dry skin should choose cream-like sunscreens; medium skin generally does not have strict regulations, and lotion-like sunscreens are suitable for all skin types.
2. Calculate the SPF value
Generally speaking, the higher the SPF index, the longer the protection is given.
3. Understand the applicable groups of different sunscreens
Different sunscreen products have different applicable objects.
A good idea is to try it on the inside of your wrist before buying. If the skin is red, swollen, painful and itchy within 10 minutes, it means that there is an allergic reaction to the product , and you can try a product with a lower SPF than this one. If there is still a reaction, it is best to give up the brand of sunscreen.
4. Skin quality test
Due to the difference in oil secretion, the skin texture will change, so a skin texture test should be done. Oily skin should choose foam cleansers with strong cleansing power and water-based sunscreens with strong penetration; dry skin should choose milky cleansers and cream-like sunscreens; neutral skin has a wider selection. Lotion-like, spray-like sunscreens are basically suitable for all skin types.
pregnant women and children
1. Reject whitening sunscreens
Pay attention to the ingredients contained in sunscreens, and do not use sunscreens that also have whitening effects during pregnancy . Because some sunscreens with whitening functions have added harmful metal elements, such as mercury, lead, arsenic or applied a lot of finely ground titanium dioxide . The long-term absorption of mercury by the skin can lead to nervous system disorders, vision loss, kidney damage, hearing loss , and sensitive skin and mucous membranes can also enter the embryo from the mother, affecting embryonic development .
2. Avoid sunscreens that have quick-acting skin rejuvenation effects
Studies have found that when a small amount of hormones are added to sunscreen products , the skin will become plump and moisturizing, but after a large number of applications, dryness and spots will appear . The long-term application of hormone sunscreen products will damage the cells, the skin will get closer to aging, and the hormones are not good for the fetus.
3. Do not touch substances that cause skin allergies
Preservatives and pigments are substances that must not be "stained" during pregnancy. At the same time, they are the three major substances that cause skin allergies. The more complex the fragrance ingredients and the larger the dosage, the heavier the stimulation, the easier it is to cause skin allergies and photosensitivity reactions .
4. When buying sunscreen products, pay attention to the labels on the packaging
The signs on the package include product name, manufacturer and address, health license , production license , name of fulfillment standard, production date, shelf life or production batch number and expiration date, application instructions, etc. In addition, sunscreen products must have a special-purpose license number on the label. When purchasing imported cosmetics, you should also look for the import license number and the name and address of the distribution agent.
5. Preferred physical sunscreen
6. Use the test
Be sure to test the skin on the back of the ear before use, and it can be used on a large area after half an hour if there is no sensitive symptoms.