Glossary entry

Occlusive.

Definition

What it means.

An ingredient that forms a physical barrier on the skin surface to prevent water loss through evaporation. Petroleum jelly is the most common occlusive, but it creates a fully airtight seal that prevents skin from breathing. Beeswax is a natural occlusive that creates a breathable barrier — it reduces water loss while still allowing skin to function naturally. This is why Numbrrrz uses Organic Beeswax instead of petroleum.

Beeswax

A natural wax produced by honeybees to build their honeycomb. In lip care, beeswax serves as a breathable protective barrier that locks in moisture without suffocating the skin. Unlike petroleum, beeswax allows air and moisture vapor to pass through while shielding lips from wind, cold, and environmental stressors. It also contains natural vitamin A which supports skin cell turnover.

Petroleum (Petrolatum)

A semi-solid mixture of hydrocarbons derived from crude oil refining. Commonly used in conventional lip balms as an occlusive barrier. While effective at preventing moisture loss, petroleum does not add moisture — it only traps what is already present. It can also prevent skin from breathing naturally and may contain trace contaminants. Numbrrrz does not use petroleum in any of its products.

Transepidermal Water Loss (TEWL)

The process by which water passes through the skin from the inside and evaporates from the surface. Lips have a very thin skin barrier and no oil glands, making them particularly susceptible to TEWL. Occlusives like beeswax reduce TEWL by creating a barrier, while emollients like coconut and jojoba oils help maintain the skin's own moisture retention capacity.