Propylene Glycol (MPG)
CAS 57-55-6 C3H8O2
- CAS number
- 57-55-6
- EC number
- 200-338-0
- Formula
- C3H8O2
- Molar mass
- 76.09 g/mol
- Appearance
- Clear colourless viscous, near-odourless hygroscopic liquid.
- HS code
- 2905.32
Propylene glycol is a low-toxicity diol that does three unrelated jobs well: it holds water, it depresses freezing point, and it dissolves things that neither water nor oil will carry. That range is why one molecule appears in food flavourings, e-liquids, pharmaceutical solutions, cosmetics, aircraft de-icing fluid and unsaturated polyester resin. Commercially it splits into two streams that are not interchangeable on paper — industrial grade for resins, coolants and de-icing, and USP/EP or food grade where an ingestible or pharmaceutical specification applies. Ehlinar supplies industrial and USP/food grades.
Applications
Grades & packaging
Industrial/technical ≥99.5% and USP/EP/food-grade (FCC/Kosher) — the two main commercial streams (PG-Industrial vs PG-USP).
- 215–220 kg drums
- IBC (~1250 kg)
- ISO tanks
- Bulk
How we supply
- Certificate of Analysis (CoA), lot-specific where available
- Safety Data Sheet (SDS / MSDS)
- Technical Data Sheet (TDS)
- Certificate of Origin / Certificate of Conformity
Independent third-party inspection can be arranged on request, with the agency and scope agreed per trade. Representative samples can be requested for qualification, subject to supplier availability. We recommend incoming quality control against the agreed CoA.
Quoted on standard Incoterms (e.g. EXW, FOB, CIF, DAP) as agreed per trade. Delivery region, packaging and grade are confirmed per quote.
Documents and services above are subject to supplier availability and confirmed per quote; nothing here is an offer.
Typical / indicative values — not a binding specification
| Property | Typical |
|---|---|
| Assay (industrial/technical) | ≥99.5% |
| Grade streams | PG-Industrial and PG-USP/EP (FCC) |
| Hygroscopicity | Hygroscopic — keep sealed |
| Shelf life | ~2 years, sealed |
Also known as
1,2-propanediol · Propane-1,2-diol · Monopropylene glycol (MPG) · Methyl ethylene glycol · Dowfrost
Frequently asked questions
- Industrial or USP grade?
- USP/EP/FCC for food and pharma; industrial grade for resins, de-icing and coolant.
- Is propylene glycol the same as ethylene glycol?
- No. Propylene glycol is low-toxicity and is available in USP/food grades tested against the applicable pharmacopeial and food standards; ethylene glycol is toxic. They are not interchangeable.
- How is it stored?
- Sealed (it is hygroscopic), in stainless/HDPE/lined steel; roughly a two-year shelf life.
- How much propylene glycol is needed for freeze protection?
- More than the equivalent ethylene glycol solution, because propylene glycol depresses freezing point slightly less effectively. Around 50 percent is the common reference point for hard-freeze protection. It is also the more viscous of the two, so pump and heat-exchanger duty are worth checking rather than assuming a straight swap.
- Can industrial grade be used in food or pharmaceutical production?
- No. The distinction is documentary as much as chemical: food and pharmaceutical use calls for material certified against the relevant pharmacopoeial or food-grade specification. Industrial grade is not tested or certified to those limits even where the assay figure looks similar.
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Related products
Figures and identifiers here are compiled from public references and provided for general information; they are indicative, not a specification. See all products.