The radiation characteristics of sunlight rays can be divided into ultraviolet (200-400nm), visible light (400-700nm) and infrared (700-3000nm) according to the size of wavelength. Ultraviolet ray is different according to wavelength again, subdivide again for UVC of short wave ultraviolet ray, UVB of medium wave ultraviolet ray and UVA of long wave ultraviolet ray, the ultraviolet ray that the skin contacts directly in daily life is 95% A.
With the worsening of environmental pollution and the destruction of atmospheric ozone layer, long-term solar radiation will have adverse effects on the skin, such as inducing skin aging, dermatitis, and even the occurrence of skin tumors. Generally speaking, short-wave ULTRAVIOLET UVC rays with a wavelength of 200-290nm are basically absorbed by the ozone layer in the atmosphere, and the remaining small amount reaches the ground, which will not cause harm to human body. UVB rays, which have a wavelength of 290-320nm, have a strong physical pathological behavior on the skin, penetrating the epidermis and cuticle of the skin, and most of them are absorbed. Short-term exposure can cause acute erythema reaction on the skin, while long-term exposure can increase the risk of skin cancer. UVA rays, which have a wavelength of 320 to 400nm, are far less energetic than UVB rays, but their damage to the skin is cumulative. They can penetrate layers and even subcutaneous tissues, which, in addition to producing large amounts of melanin, are also thought to be likely to lead to skin cancer.
King, chairman of Shenzhen LightS Technology Co., LTD. At present, people mentioned sunscreen, according to the mechanism can be roughly divided into uv absorbent and UV scatterer. Uv scatterer mainly USES titanium dioxide, zinc oxide and other inorganics to scatter or reflect uv to reduce the damage of UV to the skin. These substances form a barrier layer on the skin's surface to prevent ultraviolet light from hitting the skin directly. And ultraviolet absorption agent, basically use their molecule to absorb light energy from ultraviolet ray, convert it into heat energy or harmless visible light to release energy, thus effectively prevent ultraviolet ray to the skin tanning, sunburn effect.
The choice of bask in agent is used, it is the core place that prevents bask in cosmetic. These years, a few prevent prevent cosmetic to add at will bask in agent breed and dosage, cause prevent bask in the effect not quite, and cause harm to the skin itself. If too much use of inorganic sunscreen will block pores, easy to cause skin diseases; And abuse ultraviolet absorption agent, regardless of the occasion to improve the so-called SPF value, in addition to its physical and chemical stability and light stability, but also very easy to cause skin allergy and other symptoms. Through many years of practice of sunscreen cosmetics formulation, based on the characteristics of anti-sensitivity, the choice of sunscreen and the influence of the amount of sunscreen on the effect of sunscreen were studied, and the suggested formula was provided.