Is Glycol Safe?

August 31, 2020

Glycol Safety 101: Using Safety Data Sheets


This article will answer safety concerns associated with the safety of both propylene and ethylene glycol solutions.  It will be important to remember that this article is referring to inhibited glycols such as DOWFROSTTM and DOWTHERMTM propylene glycol and ethylene glycol solutions.


Is propylene glycol safe?

The short answer is “Yes.”  There are very few hazards associated with inhibited propylene glycols such as DOWFROSTTM and DOWFROST HDTM.


Is ethylene glycol safe?

This answer is a bit more complicated, but still fairly simple.  While inhibited ethylene glycols such as DOWTHERM SR-1TM are generally safe, there are some hazards that one should be aware of, especially when compared to propylene glycol.


Where can I find glycol safety information?

The best place to start when trying to understand if propylene glycol is safe and if ethylene glycol is safe is to review their respective SDS sheets.  What is an SDS?  It is an acronym for Safety Data Sheet.  In the past, they have been referred to as MSDS or Material Safety Data Sheet.  You can access the various SDS sheets for various mixtures of DOWTHERM SR-1TM, DOWFROSTTM and DOWFROST HDTM in our Library of Glycol SDS and Properties Charts.

These SDSs indicate a broad range of information including Hazards, First Aid Measures, Firefighting Measures, Handling & Storage, Disposal Considerations, Transport Information, and a plethora of other items.

It is on these sheets that you will see that DOWFROSTTM is not considered a hazardous material (SDS page 1) and that no emergency medical treatment is required if ingested (SDS page 2).  DOWTHERMTM, on the other hand, is considered hazardous (SDS page 1) and requires special care if ingested (SDS page 3).

For additional handling and safety information, check out our article on How to Handle, Store and Safely Dispose of Used Propylene and Ethylene Glycol.


What do I need to know if I am transporting glycol?

The first thing to understand is what containers are OK to use.  The SDS will indicate suitable materials for the container.  Note that only uses suitable materials when shipping glycol.

You will also want to understand any special transportation numbers that may be required.  This would include the UN (United Number) or NA (North American) numbers.  These too are listed on the SDS, if applicable.  You will see that DOWFROSTTM propylene glycol is not regulated and does not have a UN number.  However, DOWTHERMTM ethylene glycol is regulated and its UN number is 3082.  This designation helps transport professionals better understand the fluid they are moving.

Glycol Safety How to Handle Glycol Spill

Another key piece of information is understanding how to handle any spills.  The propylene glycol safety data sheet indicates very similar actions as the ethylene glycol safety data sheet.  In both cases, the fluid should NOT be dumped down a sewer, on the ground or into any body of water.

The final number you may come across is something called a CAS Registry Number, also known as a CASRN or CAS Number. This is a unique numerical identifier assigned by the Chemical Abstracts Service (CAS) to every chemical substance. The CASRN might be referenced for regulatory purposes and can be found in the Safety Data Sheet.


Where Should I Keep My Safety Data Sheets?

It is best to not only read and understand the glycol safety data sheets but to also keep one handy anywhere you use glycol.  While both propylene glycol and ethylene glycol are relatively safe, there are some special considerations to heed should an accident occur.  Inhibited glycols such as Food Grade DOWFROSTTM Propylene Glycol, DOWFROSTTM HD Propylene Glycol and DOWTHERMTM Ethylene Glycol are great additions to your heating and chilled water systems; and, if used as directed with the proper precautions, they are both very safe.


Josh earned his BS degree in Mechanical Engineering from Case Western Reserve University. He also holds a PE license. Josh has been an integral part of the team for 16 years. In his spare time, Josh spends time with his wife and four daughters, plays golf, volunteers with local charities and plays an active role in his church.

Go Glycol Pros LogoGo Glycol Pros is a distributor of DOW® heat transfer fluid for over 20 years. We sell glycol online with no accounts or order minimums required. Available in 275 gallon tote, 55 gallon drum or 5 gallon pail, high purity DOW antifreeze is premixed with deionized water (DI water) at our in-house facility and ships out within just one business day. Our inhibited glycols include: DOWFROST HD propylene glycol, DOWFROST food grade propylene glycol and DOWTHERM SR-1 ethylene glycol.

Explore more helpful tips and advice at Our knowledgeable glycol experts are ready to help you with your latest hydronic HVAC project.

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Disclaimer: Go Glycol Pros and it’s affiliates can not be held liable for issues caused by use of the information on this page. While the- information comes from many years of experience and can be a valuable tool, it may not take into account special circumstances in your system and we therefore can not take responsibility for actions that result from this information. Please feel free to contact us if you do have any questions.