Polyethylene glycol (PEG) 800, also known as polyethylene oxide (PEO) 800 or polyoxyethylene 800, is a type of polymeric compound that belongs to the polyethylene glycol family. PEGs are composed of repeating units of ethylene oxide (CH2-CH2-O) and are widely used in various industries and applications due to their unique properties. The number "800" in PEG 800 refers to the approximate molecular weight of the polymer.

Here are some key characteristics and uses of PEG 800:

1. Molecular Weight: PEG 800 has a relatively high molecular weight, which means it consists of a larger number of ethylene oxide units compared to lower-weight PEGs. This molecular weight can impact its physical and chemical properties.

2. Solubility: PEG 800 is highly soluble in water and many organic solvents, making it a versatile compound for various formulations and applications.

3. Lubrication: PEGs, including PEG 800, are often used as lubricants in various industries, including pharmaceuticals and the food industry. They can reduce friction and provide a smooth, slippery surface.

4. Pharmaceuticals: PEG 800 is used in pharmaceuticals as an excipient (inactive ingredient) in drug formulations. It can improve the solubility and bioavailability of certain drugs, especially poorly water-soluble compounds.

5. Personal Care Products: PEGs are commonly found in personal care and cosmetic products, such as skin creams, lotions, and shampoos, due to their emollient and moisturizing properties.

6. Industrial Applications: PEG 800 is used in industrial processes, such as in the production of detergents, as a surfactant, and in the manufacture of plastics.

7. Chemical Reactions: PEGs like PEG 800 can be used in chemical reactions as a stabilizer, dispersant, or reaction medium, particularly in polymerization reactions.