Occlusives are a moisturizing ingredient that creates a barrier on top of your skin to prevent water loss.
Occlusives help maintain skin hydration and prevent dryness, and tend to be found in moisturizers alongside humectants (working to attract moisture to the skin) and emollients (which smooth and soften the skin). Common occlusives include petrolatum, silicones, squalane, shea butter, beeswax and castor oil.