The majority of sunscreens on the market are made with chemical (synthetic) UV filters. These products typically include a combination of two to six of the following active ingredients: oxybenzone, avobenzone, octisalate, octocrylene, homosalate and octinoxate. These ingredients work rubbing them into the skin. The filters then absorb UV radiation. That radiation is then released as heat. The filters and biproducts of these filters are absorbed into the blood stream. As these sunscreens with synthetic filters are used, they are broken down and absorbed into the bloodstream. You cannot simply wash it all out of your skin or from inside your blood stream or remove them from the body. The ingredients will eventually be voided from the body over time.
Some sunscreens have mineral (physical) filters consisting of titanium dioxide (TiO2) and zinc oxide (ZnO), and while they do have scattering and reflective properties, it is not because of these properties that they become effective sunscreens! Rather, it is because of its semiconductor-like electronic properties as solids. The emphasis on scattering and reflecting on one hand, and absorbing on the other, through the ‘chemical’ and ‘physical’ grouping of UV filters is technically incorrect, as ‘physical’ blockers also absorb UV rays. The physical/mineral filters are not absorbed into the skin. Mineral filters will wash off.
Cosmetics and sunscreens which are labeled as OTC products in the U.S. may contain synthetic and/or natural inactive ingredients. Some of these ingredients will be absorbed into the skin and into the blood as above, depending on the size of the molecules that make up each ingredient.
Many include inactive ingredients that are made from petroleum, such as silicon and dimethicone.
Some sunscreens also include natural ingredients. While these ingredients may also be absorbed into the skin, they are derived from natural sources, having less of a chance of toxicity.
Washing them off
Depending on the sunscreens active and inactive ingredient profile, they may simply wash off with mild soap or need some really strong dish detergent.
Love Sun Body 100% Natural Origin Mineral sunscreens contain only non-nano mineral filters and plant based ingredients. They will wash off with mild soap and water.