Propylene glycol

1,2-Propanediol is an organic compound with the chemical formula C3H8O2. Under normal conditions, it is a colorless, viscous liquid, almost odorless with a faintly sweet smell upon close inspection. It is miscible with water, ethanol, and various organic solvents. There are two isomers of propanediol; unless otherwise specified, propanediol generally refers to 1,2-propanediol.
1,2-Propanediol can be prepared through methods such as hydration of propylene oxide, hydrolysis of 1,2-dichloropropane, and oxidation of propylene. In cosmetics, toothpaste, and soap, it can be used in combination with glycerin or sorbitol as a humectant. In hair dyes, it serves as a moisture regulator and hair leveling agent. It is also used as an antifreeze agent and finds applications in cellophane, plasticizers, and the pharmaceutical industry.

1. Properties: Colorless, viscous, stable hygroscopic liquid, almost odorless and tasteless, flammable, low toxicity.

2. Boiling point (ºC, 101.3 kPa): 187.3

3. Melting point (ºC, flow point): -60

4. Relative density (g/mL, 20/20ºC): 1.0381

5. Relative density (20°C, 4°C): 1.0362

6. Refractive index (n, 20ºC): 1.4329

Safe storage conditions: Although this product does not spontaneously combust, it is flammable. It remains stable during long-term storage but absorbs moisture when exposed. Storage and transportation containers should be made of galvanized iron drums, aluminum, or stainless steel. It should be stored and transported in accordance with general low-toxicity chemical regulations. Avoid contact with water and humid environments. Storage tanks must be kept clean, dry, and rust-free. They must be stored in areas with dikes, good ventilation, away from direct sunlight, open flames, and other heat sources. Large storage tanks (with a capacity of 100 m³ or more) are recommended to use nitrogen sealing. Keep containers tightly closed. Keep dry.
Storage temperature: Maximum 40°C.