Dipropylene glycol

Dipropylene glycol is a mixture of three isomeric chemical compounds, characterized by its colorless, nearly odorless liquid state and high boiling point[1]. It is known for its low toxicity, making it a versatile ingredient in various industries.

Uses

Dipropylene glycol finds applications as a plasticizer, an intermediate in industrial chemical reactions, a polymerization initiator or monomer, and as a solvent[1]. Its low toxicity and solvent properties make it an ideal additive for perfumes and skin and hair care products, where it functions as a humectant, attracting and retaining moisture to combat dryness[2]. It is also a common ingredient in commercial fog fluid, used in the entertainment industry's fog machines[1].

Skincare and Cosmetics

In skincare and cosmetics, dipropylene glycol is valued for its ability to modify the structure of the outermost skin layer, allowing accompanying substances to penetrate deeper into the skin[2]. It is also a useful solvent, being completely soluble in water and able to dissolve oils[2]. The US Environmental Protection Agency (EPA) has determined that, under current conditions of use, dipropylene glycol is generally considered safe for skin and hair care products due to its low hazard[2]. However, it can cause contact dermatitis in some individuals, and a patch test is recommended before using a new product containing this ingredient[2].

Industrial Applications

Di propylene glycol is produced as a byproduct of propylene glycol production and is used as a chemical intermediate across various industries[5]. It is a component in the production of high volume plasticizer, an initiator in urethane polyols, and a reactant in unsaturated polyurethane resins[5]. Additionally, it is used in the production of cutting oils, hydraulic brake fluid, solvents for agricultural chemicals, printing inks, nitrocellulose, cellulose acetate, lacquers, and coatings[5]. It also plays a role in the refining industry as an extraction solvent to extract aromatics[5].

Safety and Concerns

While dipropylene glycol is generally considered safe and non-irritating for most people, it is not without some concerns[2]. It can cause minor skin irritation in some individuals, and those with sensitive skin should consult with a dermatology provider before using products containing this ingredient[2]. The Environmental Working Group (EWG) notes that dipropylene glycol scores higher for common concerns if used in product forms that are inhalable or intended for use around the eyes, due to increased risk of absorption and respiratory concerns[4]. However, it is not currently on EWG's Skin Deep Restricted or Unacceptable Lists[4].

In summary, dipropylene glycol is a versatile and widely used chemical with applications in various industries, including skincare and cosmetics, due to its low toxicity and solvent properties. While it is generally considered safe, it can cause minor skin irritation in some individuals, and caution should be exercised when using products containing this ingredient, especially for those with sensitive skin.

Citations:

[1] https://en.wikipedia.org/wiki/Dipropylene_glycol

[2] https://curology.com/blog/dipropylene-glycol-in-skincare-what-is-it-and-what-does-it-do/

[3] https://shop.perfumersapprentice.com/p-6663-dipropylene-glycol-dpg.aspx

[4] https://www.ewg.org/skindeep/ingredients/702123-DIPROPYLENE_GLYCOL/

[5] https://www.solventis.net/products/glycols/di-propylene-glycol/