Glycols and Glycol Ethers

About Glycols and Glycol Ethers

Buy ethylene glycol, propylene glycol, and specialty glycol products from Alliance Chemical in Laboratory, Technical, and Semiconductor purity grades. Pre-mixed and concentrated formulations available in quarts through 330-gallon IBC totes.

Products In This Collection

This collection includes ethylene glycol 50/50 (CAS 107-21-1), 100% ethylene glycol inhibited, ethylene glycol semiconductor grade (99.5%+ assay), ethylene glycol 60/40, and 100% propylene glycol inhibited (CAS 57-55-6). Propylene glycol is often selected for food-processing support systems and closed-loop heat-transfer systems where lower toxicity is required.

Common Applications

Ethylene glycol formulations serve as the primary heat transfer fluid in closed-loop HVAC systems, industrial chillers, data center cooling systems, and automotive antifreeze applications. Propylene glycol inhibited is used in food processing facilities, breweries, and pharmaceutical plants. Semiconductor-grade ethylene glycol provides ultra-pure cooling for cleanroom equipment. Glycol-based coolants are also used in solar thermal systems, geothermal heat pumps, and hydronic heating and cooling.

Why Buy From Alliance Chemical

Every glycol product ships with a Safety Data Sheet (SDS) and Certificate of Analysis (COA). Alliance Chemical provides same-day shipping with no minimum orders, from bench-scale quarts to bulk IBC totes.

Related: See the Ethylene Glycol, Coolants and Antifreeze, and Water Treatment collections.

Frequently Asked Questions

What is the difference between ethylene and propylene glycol for chiller systems?

Ethylene glycol offers superior heat transfer efficiency and lower viscosity at low temperatures, but it is toxic to humans and animals. Propylene glycol has a lower heat transfer efficiency but is used where low toxicity is required, such as in food processing facilities or residential HVAC systems. In industrial chillers, the choice depends on local environmental regulations and the specific thermal requirements of the heat exchanger.

Does inhibited glycol protect against corrosion in copper piping?

Yes, inhibited glycols contain a proprietary package of dipotassium phosphate and other buffers designed to passivate metal surfaces and prevent galvanic corrosion. According to ASTM D1384 standards, these inhibitors maintain a stable pH (typically 8.0 to 10.0) to protect copper, brass, steel, and cast iron components. Without inhibitors, glycol naturally degrades into organic acids that aggressively attack system metals.

What are the DOT shipping requirements for bulk ethylene glycol?

Under DOT 49 CFR 172.101, ethylene glycol is only regulated as a hazardous material when shipped in a single container that meets or exceeds the Reportable Quantity (RQ) of 5,000 pounds (approximately 535 gallons). For shipments below this threshold, such as individual 55-gallon drums, it is generally shipped as non-regulated. However, if it meets the RQ, it must be labeled as Environmentally Hazardous Substance, Liquid, N.O.S., Class 9, UN3082.

How do I calculate the glycol concentration needed for burst protection vs freeze protection?

Freeze protection is required when the system must remain pumpable, requiring a concentration where no ice crystals form at the lowest expected temperature. Burst protection allows the fluid to form a slush but prevents the expansion that ruptures pipes, typically requiring a lower concentration (approx. 35% for -20°F). Engineers should consult concentration charts for specific CAS 107-21-1 or CAS 57-55-6 formulations to ensure the fluid's slush point remains above the system's mechanical limits.

Can I mix different brands of inhibited glycol in the same system?

Mixing different brands is generally discouraged because inhibitor chemistries (such as OAT, NOAT, or phosphate-based) can react, causing the inhibitors to precipitate out of the solution. This can lead to localized corrosion and clogged heat exchangers. If mixing is unavoidable, a laboratory compatibility test or a full system flush as per ASHRAE guidelines is recommended to ensure the resulting pH and reserve alkalinity remain within specification.

What PPE is required by OSHA for handling concentrated glycols?

Per OSHA 29 CFR 1910.132 and 1910.133, workers should wear chemical splash goggles and nitrile or butyl rubber gloves to prevent skin and eye contact. While Propylene Glycol USP has low vapor pressure, Ethylene Glycol handled at high temperatures or in aerosol form may require respiratory protection if concentrations exceed the OSHA PEL of 50 ppm (ceiling). Always refer to Section 8 of the SDS for specific exposure controls.

How do I dispose of used industrial glycol according to EPA regulations?

Used glycol is not automatically classified as hazardous waste under EPA RCRA (40 CFR Part 261) unless it has become contaminated with heavy metals (like lead or chrome from the system) or has been mixed with other hazardous solvents. However, many state and local municipalities prohibit the disposal of glycol into sanitary sewers. It is mandatory to perform a waste characterization before disposal through a licensed hazardous waste contractor.

Is Propylene Glycol USP grade required for all food-contact applications?

Yes, any application where the glycol may incidentally come into contact with food, beverages, or pharmaceuticals requires USP (United States Pharmacopeia) or FCC (Food Chemicals Codex) grade Propylene Glycol. This ensures the material meets strict purity standards for heavy metals and impurities. Technical grade glycol may contain industrial byproducts that are not safe for human consumption or pharmaceutical use.

What is the typical shelf life of inhibited glycol in original packaging?

Inhibited glycol typically has a shelf life of 2 years in its original, unopened container when stored between 40°F and 100°F (4°C to 38°C). The inhibitors are stable but can slowly deplete if exposed to air or extreme temperature fluctuations. For long-term storage, it is recommended to test the reserve alkalinity and pH annually to ensure the inhibitor package remains active before installing it into a system.