What are the main ingredients in sunscreen?

In summer, many girls are reluctant to go out, but if friends invite them out, they still have to go out. But before going out, you must prevent tanning and sunburn. Sunscreen is one of the most favorite products of girls in summer. So, is there any harm to applying sunscreen on your face every day? If you want to know this result, you must first know what are the main ingredients of sunscreen?

Sunscreen (UVA)

Ultraviolet light UVA is present throughout the day. It has a short wavelength but strong penetrating power. It can penetrate most transparent glass and plastics and reach the dermis of the skin directly. It can reduce the content of hyaluronic acid that binds water in the skin, making the skin dry, accelerate the formation of melanin, and darken the skin color. After reaching the dermis of the skin, it can destroy the collagen fibers and elastic fibers of the dermis of the skin, leading to skin aging. It is also an important cause of skin cancer. Usually the protection index of ultraviolet UVA is expressed as PA+ or PPD, PA+=PPD2, and so on, which means that it can protect against ultraviolet UVA for 2 hours.

UVA absorber name, safety evaluation

Benzophenone-32-hydroxy-4-methoxybenzophenone may cause urticaria, eczema and other phenomena, as well as photosensitivity reactions.

Benzophenone-42-hydroxy-4-methoxybenzophenone sulfonic acid may cause urticaria, eczema and other phenomena, as well as photosensitivity reactions.

Parsol1789, good effect, no adverse reactions.

Salicylates, cinnamates and anthranilates are currently considered to be safer sunscreen ingredients with no reports of irritation.

Sun protection (UVB)

UVB rays can penetrate the epidermis, causing the skin to become rough and produce wrinkles and spots. The most lethal period is from 10:00 am to 2:00 pm. UVB rays are strongest in places with a strong refractive index of sunlight, such as the seaside and grasslands, so UVB is also called "leisure ultraviolet rays." The protection index for ultraviolet UVB is expressed as SPF, followed by a number indicating the multiple. A multiple is 15 minutes to 20 minutes, and the time to protect against UVB is 15 or 20 minutes multiplied by the multiple. For example, SPF15 means 15 times the sun protection strength, which means the time to protect against UVB is 15 or 20 minutes multiplied by 15 times. The larger the multiple, the longer the sun protection time and the better the sun protection effect.

UVB absorber name, safety evaluation

PABA, which can cause skin irritation and allergic reactions

DEA-Methoxycinnamate, not available

Ethyl dihydroxypropyl PABA, not available

High methyl salicylate, not available

Octyl dimethyl PABA, after exposure to light, will decompose into carcinogenic nitrosamines

Phenylbenzimidazole sulfonic acid may cause cell chromosomal changes and may be carcinogenic.