Why we added coated non-nano titanium dioxide to our mineral sunscreen

Non-nano titanium dioxide is widely utilized in the cosmetics industry as a premier mineral UV filter, prized for providing robust, broad-spectrum defense against harmful UVB and short UVA rays. Because its individual particles are engineered to be larger than 100 nanometers, this mineral sits safely on top of the skin barrier rather than absorbing into the bloodstream making it highly advantageous for sensitive skin types or causing the severe coral bleaching associated with traditional chemical filters. This physical structure makes it exceptionally safe for sensitive dermal barriers and highly attractive for brands seeking to target eco-conscious consumers under "reef-safe" and "hypoallergenic" marketing definitions.

Despite these notable safety and consumer benefits, raw non-nano titanium dioxide possesses a significant chemical vulnerability known as photocatalysis. When exposed to solar ultraviolet radiation, the mineral acts as a powerful photocatalyst, absorbing light energy and causing its internal electrons to jump to higher energy states. These highly reactive electrons immediately interact with ambient moisture and oxygen resting on the surface of the skin. This interaction initiates an unintended chain reaction that rapidly generates aggressive free radicals, known as reactive oxygen species (ROS), including harmful hydroxyl radicals and superoxide anions.

The resulting surge of unchecked reactive oxygen species presents severe dangers and disadvantages to both the product formulation and long-term dermal health. On a structural level, these volatile free radicals induce oxidative stress that degrades the active ingredients within the topical cream, diminishing the sunscreen's protective lifespan during sun exposure. More critically, at a cellular level, these molecules aggressively steal electrons from healthy skin cells, attacking vital lipid membranes, structural proteins, and cellular DNA. This microscopic degradation triggers localized inflammation, accelerates premature skin aging, and potentially elevates long-term skin cancer risks, fundamentally undermining the primary health purpose of applying a sun protectant.

To neutralize these photocatalytic dangers, we and our manufacturers utilize a high-quality, coated variant of non-nano titanium dioxide. During production, each mineral particle is wrapped in a microscopic, multi-layered protective jacket consisting of inert shielding materials (silica and stearic acid). This physical barrier ensures that while the core mineral safely absorbs UV light, the resulting energy and free radicals remain permanently trapped within the coating layers. By preventing the raw mineral core from making direct contact with ambient moisture or oxygen, this specialized shield successfully suppresses all photocatalytic activity and locks in safe UV protection.

However, by incorporating highly sophisticated mineral coatings introduces a substantial financial hurdle, as pharmaceutical-grade coated non-nano titanium dioxide is significantly more expensive to source and complex to formulate than its raw counterpart. Because of these heightened manufacturing expenses, many independent, small-batch, or artisanal brands intentionally choose to utilize cheaper, uncoated minerals. To justify the omission of these costly coatings, such brands frequently leverage "100% natural," "pure," or "chemical-free" marketing strategies, appealing to purist consumers.

When companies opt for these cheaper, uncoated formulas, they must implement alternative formulation strategies to handle the inevitable creation of solar free radicals. (EWG -sunscreen guide)

To bypass the need for constant reapplication during high intensity water sports, we chose to use a very small percentage of coated non nano titanium dioxide along with non-nano zinc oxide and lock these mineral filters into a heavy, hydrophobic base made of beeswax, creating a highly water-resistant paste that sticks firmly to the skin preventing them from washing off. When coated non-nano titanium dioxide & non-nano zinc oxide is combined with a beeswax base, it creates a supreme double-layer of defense that eliminates photocatalytic danger to the user, as the silica shell traps the free radicals while the beeswax physically glues the protective particles to the face. While this heavy method successfully prevents immediate mineral runoff, it does not permanently eliminate the environmental footprint of the minerals; it simply alters the timeline of how they enter the sea.

Does Sunsessions coated non-nano titanium harm the seabed and sea life? 

Once our mineral sunscreen eventually leaves the skin—either through micro-shedding in the surf, swimming or being physically wiped off by the consumer, it begins a multi-staged environmental lifecycle in the ocean.

 Initially, the heavy beeswax resists water dissolution and must be slowly broken down by marine bacteria over several weeks or months, during which the encased coated minerals remain entirely inert and harmless to coral reefs.

 Once the outer beeswax barrier finally biodegrades and releases the mineral particles, the open ocean water strips away and dissolves the outer organic stearic acid wrapper quickly. The high PH and salinity of the ocean dissolve the inner silica shell over a period of 48 to 96 hours, converting the silica into harmless silicate—a vital native nutrient that marine organisms like diatoms and sea sponges use to build their skeletons. Only at the very end of this extended timeline is the raw non-nano titanium dioxide core finally exposed to the marine environment. 

*******Because our sunscreen contains natural beeswax and a high-quality coated titanium, it causes no harm to sea life for the first few months while it is floating or settling onto the seabed. It does not bleach coral or harm fish because photocatalysis is entirely shut down by the silica “armor”. Once the titanium particles are finally exposed, this time release mechanism allows the ocean’s natural currents to widely disperse and dilute the particles across vast distances preventing harmful toxic accumulations on any single area of the seabed or coral reef.