Thank you for your question. Both are 100% Silicone, and both are safe to use in potable (drinkable) water systems. They differ slightly in chemistry, making Waterproof Grease good as an installation aid for parts that won’t be moving much and Silicone Grease better as a long-term lubricant for moving parts in plumbing systems. Please note: we have only tested these greases for use in residential plumbing applications, and cannot warrant their fitness for other applications.