Food-Grade Glycol Requirements For Food Processing Cooling Systems August 4, 2026 Glycol is the workhorse coolant in most commercial food processing cooling systems — but not just any glycol. Food processing facilities that use glycol in systems where incidental food contact is possible must use food-grade (GRAS-listed) propylene glycol, not the industrial ethylene glycol used in HVAC systems or general industrial applications. Understanding this distinction, and ensuring your systems use the right coolant, is a food safety requirement, not a preference. Why Food-Grade Glycol Is Required Two classes of glycol are commonly used in cooling applications: Ethylene glycol (EG): highly effective coolant; widely used in commercial HVAC, automotive, and industrial applications; TOXIC — not acceptable in food processing areas where contact with food is possible Propylene glycol (PG), food-grade (USP or GRAS): effective coolant; recognized as Generally Recognized As Safe (GRAS) by FDA; acceptable for use in food processing where incidental contact with food may occur > This is not a minor distinction. Ethylene glycol toxicity means that a leak or spill in a food contact area can contaminate product, trigger a recall, and expose the facility to serious regulatory and liability consequences. If your system uses ethylene glycol in a food environment, this is a hazard that requires immediate correction. Where Food-Grade Glycol Is Required Food-grade propylene glycol is required in any cooling system where: The coolant could contact food directly (e.g., immersion chilling, jacketed vessels with potential for jacket-to-product leak) The coolant could contact food-contact surfaces through leaks or splashes in food production areas The system is in a food contact area and the potential for incidental contact cannot be fully eliminated Food-grade PG is not required for systems in non-food-contact areas (mechanical rooms, exterior equipment, cooling towers) — but verify with your food safety team and applicable regulations. Food-Grade Glycol Performance Characteristics Property Ethylene Glycol vs. Food-Grade Propylene Glycol Freeze protection (50% concentration) EG: -34 degrees F / PG: -28 degrees F Heat transfer efficiency EG: higher / PG: approximately 5-10% lower at equal concentrations Viscosity EG: lower / PG: higher, especially at low temperatures; affects pump energy Toxicity EG: toxic / PG: GRAS; safe for incidental food contact Cost EG: lower / PG: typically 20-30% higher Regulatory status in food areas EG: NOT acceptable / PG food-grade: acceptable per FDA 21 CFR 184.1666 Maintenance of Food-Grade Glycol Systems The same maintenance requirements that apply to industrial glycol apply with additional consideration for food safety: pH testing quarterly: food-grade propylene glycol also degrades and becomes acidic over time; acidic coolant corrodes equipment and poses contamination risk Inhibitor level testing: food-grade glycol contains food-safe corrosion inhibitors that deplete over time Concentration verification: concentration must remain adequate for freeze protection at operating temperatures Microbial testing: glycol systems can support microbial growth; periodic microbial testing is appropriate for food processing applications Frequently Asked Questions How do I verify my current system uses food-grade glycol? Request Safety Data Sheets (SDS) for all glycol products in your facility cooling systems. Food-grade propylene glycol will be identified as USP grade or reference FDA 21 CFR 184.1666. Industrial propylene glycol and ethylene glycol products will not have these designations. Can I top off food-grade glycol systems with a different grade? No. Mixing food-grade and non-food-grade glycols, or mixing different formulations, can compromise the food-grade status of the system. Always use the same brand and grade approved for your system when adding makeup glycol. > Verify and maintain food-grade cooling systems with G&D's service team -> Contact us