Sunscreen product commonly used ingredients

① Inorganic sunscreen ingredients

Titanium dioxide: As a physical sunscreen, titanium dioxide is usually in the nanometer range (currently not allowed for use in children's sunscreen products), and appears as a white fine powder with a particle size generally between 35-60nm. The titanium dioxide used for covering effect generally has a particle size of 200~300nm.

Nanometer titanium dioxide is usually tasteless and can be used as a physical barrier against UVB and some UVA. Nanometer titanium dioxide has high stability, transparency, activity, dispersibility, non-toxicity, and no color effects.

Generally, when titanium dioxide is used as a sunscreen ingredient, it will be labeled as "titanium dioxide" in the product composition table. If it is used as a coloring agent, it is generally labeled as "CI77891" in the composition table.

Application: When titanium dioxide is used in sunscreen cosmetics, the highest allowable addition amount in Europe and the United States is 25%, and the recommended addition amount is around 5%. It can be applied to cream, lotion, and gel-type sunscreen products.

Zinc oxide: As a classic inorganic sunscreen ingredient, zinc oxide can almost completely block ultraviolet rays, is mild, unlikely to cause allergies, and has good safety.

Application: Zinc oxide can be used as a UVB and UVA sunscreen. The maximum allowable addition amount is 25%. Zinc oxide is easy to mix with nonionic surfactants and most anionic surfactants, and can easily disperse in various oils and fats to make O/W or W/O emulsion-type sunscreen products.

Both the United States and Europe allow titanium dioxide and zinc oxide as active sunscreen ingredients, and the maximum allowable addition amount is 25%. Different countries and regions have certain differences in requirements for nanomaterials, and reasonable adjustments need to be made according to product needs. Currently, the EU requires that if nano zinc oxide is added to spray-type products, it must be indicated on the packaging.

② Organic sunscreen representative

Butyl Methoxydibenzoylmethane: Belonging to the benzophenone class of sunscreens, Butyl Methoxydibenzoylmethane is currently one of the most efficient UVA sunscreens and can also synergistically enhance SPF. Its commercial name is Parsol 1789, its ultraviolet absorption band is between 310~400nm, and the maximum absorption wavelength is 360nm, which can effectively protect against UVA.

Disadvantages: Its photostability is poor, and it is prone to photodegradation under sunlight, thereby losing its sunscreen effect. It needs to be used in combination with other sunscreen ingredients to suppress its photolytic reaction. For American sunscreen products using Parsol 1789, the FDA recommends reapplying sunscreen every 2 hours.

Application: It needs to be used in combination with other sunscreen ingredients. The maximum allowable addition amount in cosmetics is usually 5%.

Benzophenone derivatives: The maximum absorption wavelength of this type of UV absorber is 325nm, with the function of preventing UVA and UVB, and has high thermal stability and photostability, but it is unstable to oxidative substances and requires the addition of antioxidants in its formula.

Application: Benzophenone-3 can be used as a UVA and UVB sunscreen, and the maximum allowable addition amount is 10%.

Benzophenone-4 can be used as a broad-spectrum UVA and UVB sunscreen, and the maximum allowable addition amount is 5%. It is widely used in various water-based sunscreen cosmetics and must be neutralized with a neutralizing agent after use. The pH after neutralization is 5.6~6.

Homosalate: Also known as salicylic acid tri-methylhexyl ester, it is insoluble in water and glycerin, but soluble in ethanol, propylene glycol, mineral oil, paraffin oil, and isopropyl palmitate.

Application: Mainly used as a UVB sunscreen, it is a UV sunscreen agent commonly used in the European Union and is regulated by Appendix VI, Section 3 of the EU cosmetics regulations, with a maximum allowable addition amount of 10%. The EU has constantly updated its requirements for this ingredient, so export products need to pay attention to regulatory changes.

Octocrylene: Insoluble in water, propylene glycol, and glycerin, Octocrylene can be mixed with ethanol, isopropanol, and isopropyl palmitate.

Application: Octocrylene can be used in sunscreens all over the world. This sunscreen agent belongs to oil-soluble chemical sunscreen agents, which can absorb UVA and UVB in the wavelength range of 250~360nm.