Anhydrous Ammonia Leak

R-717, or Anhydrous Ammonia, is widely regarded as one of the most efficient refrigerants in the world. Not only is it efficient it also has zero Ozone Depletion Potential and has a Global Warming Potential of zero. So, you have a highly efficient refrigerant with no impact on the climate. It is these two reasons why we have begun to see more and more companies and countries use Anhydrous Ammonia.

In fact Ammonia was one of the very first refrigerants to be discovered and used. This can be said for a lot of the natural refrigerants such as Ammonia, Carbon Dioxide, and the various Hydrocarbons like Propane or Isobutane. All of these were the grandfathers of refrigerants. It was in the 1930’s that CFCs and HCFC were introduced and we began to see the demand for these natural refrigerants start to dwindle.

After all, these newer CFC/HCFC refrigerants didn’t have any downsides. Natural refrigerants did. Carbon Dioxide operated at very high pressures which caused premature failures. Hydrocarbons were flammable. Ammonia was toxic and flammable. Yes folks, Ammonia is rated as a B2L from ASHRAE. This B signifies refrigerants for which there is evidence of toxicity at concentrations below four hundred parts per million. Refrigerants in the 2L sub-classification are slightly flammable and have a burning velocities less than or equal to 10 cm/s (3.9 in./s)

It is directly because of the downsides on natural refrigerants that I mentioned above that we saw the rise of CFCs and HCFC refrigerants such as R-11, R-12, R-502, R-22, etc. When these refrigerants were phased out due to their effect on the Ozone a new king of artificial refrigerants was announced, HFCs. Some of your most common HFCs out there are your R-125, R-32, R-410A, R-404A, and R-134a. These reigned supreme for about twenty years until we realized what impact that they were having on Climate Change and Global Warming.

The world had realized that we substituted one wrong for another. There had to be a better solution then these climate damaging refrigerants, right? Well folks, that is where the age old debate between natural refrigerants and artificial refrigerants come into play. Honeywell and Chemours (Formerly DuPont) have spent countless hours and money on developing a new classification of artificial refrigerants known as HFOs. These refrigerants are said to have very low Global Warming Potential while also being relatively safe. An HFO might be a 2L, but at least it is not toxic as well.

But, the problem is a lot of folks have felt they have been suckered too many times. First it was CFCs, then HCFCs, then HFCs, and now it’s HFOs? Whose to say that HFOs won’t be gone in another ten years? Why invest money into a machine that could be obsolete in a decade, or worse yet, illegal? I swear the ink wasn’t dry on the 2010 phase out of R-22 and we had already started to hear about phasing down R-410A. This constant changing can wear people out.

The appeal of natural refrigerants is enticing. They have been around for centuries. They are not damaging to the climate. These two facts alone ensure that you will never run into a phase down or phase out situation with these refrigerants. The question though is are they worth the risk? Now, when I say risk I’m not talking about Carbon Dioxide, or even Hydrocarbons for that matter. My focal point here is Ammonia.

As I mentioned earlier Ammonia is both toxic and flammable. Now many companies will minimize this and state that it is perfectly fine and safe if the proper precautions, maintenance, and regulations are followed. This very well may be true, but what happens when a mistake is made? If you’re just dealing with a smaller charged application then it’s not too big of a deal. However, if you are using Ammonia refrigerant in large quantities then disaster can strike.

Before I go further I want to preface this with that I am going to get a lot e-mails on this article. It seems that whenever I bring up Ammonia I get a lot of feedback. Some folks for it and some folks against it. Most of the time though it is folks arguing for it. So, in this article I am going to go against the grain here and try to paint you a picture of what can happen when Ammonia leaks or spills can occur and why we should be looking at alternative refrigerants.

A few years back I wrote an article about an unfortunate event in Canada. An Ammonia leak had occurred at a small town’s ice rink. Three workers, who were trying to repair the leak, died due to Ammonia exposure. An entire city block was evacuated by the local fire department. It was a tragedy for the small town. This one event, while extreme, shows you what kind of damage Ammonia can do.

To give you an even clearer picture I searched around Google and pulled Ammonia leak related stories over the past eighteen months. While fatalities are rare, they can still occur. The common theme throughout these leaks is evacuations and injuries. The sheer amount of incidents below should give you an idea of why I am not for Ammonia refrigerant use. (In large charge applications.)


If you are looking at a new system for your plant, factory, ice rink, or whatever else please consider something other then Ammonia. Review the latest HFO refrigerants out there. Or, if you want to stay with natural refrigerants then take a good hard look at Carbon Dioxide R-744. CO2 has made great strides over the past decades and is quickly becoming one of the major players within the refrigerant industry.

If you do end up going with Ammonia though just know that there is a chance of any one of the events I listed above happening at your location. It could be a small leak that is handled right away or it could be a catastrophe like what happened in Canada. Be absolutely sure you schedule proper maintenance and take any and all precautions you can so that you can give your employees and your customers a safe place to work and visit.

Thanks for reading,

Alec Johnson


Well folks, as most of you know today is Earth Day. Personally, I don’t do anything to celebrate it besides walking around my property and enjoying the view. I just cleared an area by our pond this weekend and now I’ve got a nice quiet place to relax after a day’s work.

As I was reading the news today I saw a plethora of Earth Day stores. One that stuck out to me though was that the Environmental Investigation Agency (EIA) announced that they had launched a website in honor of Earth Day. This website aims at identifying retailers within the United States who have begun to use natural refrigerants instead of HFCs. The goal here is to have the companies who have started moving forward with natural refrigerants to be recognized for leading the pack.

Before we get to the website, let’s take a look at who the Environmental Investigation Agency (IEA) is. I have not heard of them before, and when I haven’t heard of something I like to research it. EIA is a non-profit organization that was founded back in 1984 out of the United Kingdom. Today they have offices in London and in Washington DC and focus on environmental crime and abuse across the globe. Their main website can be found by clicking here. They work on wide variety of things from endangered animals and poaching all the way over to climate change and refrigerants.

The new HFC website that EIA created can be found by clicking here. At first glance when looking at this website and the map that shows you where the natural refrigerant supermarkets are within the United States I couldn’t help but laugh. Nearly every location is in California or New York. This was expected as California usually leads the way in environmental progress, but still it was quite funny to see that the closest one to me is about one-thousand miles away (I’m in Kansas City).

Regardless of how far away they are progress is progress. According to IEA there are five main companies that have been pushing their locations to move away from HFCs and switch over to natural refrigerants. These companies are: Target, Aldi, Ahold Delhaize, Whole Foods Market, and Sprouts. Each of these companies has their own innovative ways of applying these alternative refrigerants. These range from:

  • Transcritical CO2 systems
  • Cascade or indirect systems using a combination of two low-GWP refrigerants
  • Micro-distributed systems using hydrocarbon condensing units on a chilled water or glycol loop
  • Stand-alone display cases using hydrocarbons

I won’t get into the details of what every company has done over the past few years to make this listing, but instead give you a quick highlight from each company. If you wish to read more on the subject feel free to visit our ‘Sources’ section at the bottom of this article to continue reading.

Aldi has been one of the leaders here in the United States. This isn’t surprising in the slightest as they are a European based company and have European ideals. (Europe is always ahead of us when it comes to environmental changes.) According to IEA Aldi has over two-hundred stores with transcritical R-744 systems with plans to add another one-hundred by the end of 2019. Along with that they have launched R-290 propane self-contained refrigerators/freezers and they have transitioned their warehouses over to R-717 ammonia based systems.

Target is another big driver of change. So far they have over one-thousand stores using self-contained hydrocarbon refrigerators/freezers (R-290 and R-600a). They have also begun experimenting with CO2 applications. They are piloting a transcritical R-744 application in two stores and they have also begun using CO2 cascade systems in their larger stores. Also, just like Aldi, they are using ammonia R-717 in their food distribution warehouses.

The other stores haven’t done as much as Aldi and Target, but they are still making strides to cleaner refrigerants. Whole Foods, now owned by Amazon, has begun distributing propane stand-alone refrigerators/freezers across their entire store network. They have also been piloting a transcritical CO2 system in their Brooklyn, New York store. The company Ahold USA was the very first store ever in the United States to begin using a transcritical CO2 system. Lastly, Sprouts was the first grocery store in the United States to use a R-744 ejection refrigeration system.


Along with these companies being environmentally friendly and being recognized by such agencies such as the IEA they also get the added benefit of increased energy efficiency. More often than not natural refrigerants are far more efficient than your standard HFC refrigerant. Ammonia, for example, is the most efficient refrigerant out there. All of this efficiency means decreased monthly energy bills for these stores and companies. So, while there may be a larger expense up front with a natural system the business owner will make it back month to month with lower operating expenses. They also get the peace of mind knowing that natural refrigerants will never be phased out by the Environmental Protection Agency as they have no, or extremely little, impact on the climate and the Ozone layer.

While looking at the map of all of stores using natural refrigerants was comical, we do all have to start somewhere. I’m willing to bet though that the map isn’t covering every store in the country. There’s a Whole Foods and an Aldi not far from me and I bet one of those stores are using a propane based refrigerator. With each year that passes the chance of running into these systems increases. If you haven’t already familiarized yourself with them I would recommend looking into it soon.

What is interesting though was after reading this I saw very little mention of HFO refrigerants from Honeywell and Chemours. Are the HFO refrigerants being eclipsed by natural refrigerants?  Will we begin to see the mass conversion away from R-404A before HFOs can be fully rolled out? Time will tell.

Thanks for reading,

Alec Johnson



When I first started writing articles about R-717 Ammonia being used in ice rinks and in industrial refrigeration I tried to keep an open mind. However, over the past year or so I have become less and less confident with R-717 systems. I try to make my articles unbiased and to show the Pros and Cons to both sides but this is proving more difficult with R-717. Maybe I need some of you to re-convince me to the benefits of this refrigerant but as of today I am very skeptical of it’s practical applications.

Ammonia has been used as a refrigerant for nearly ninety years. While the applications have varied over the years it has always been around. It is highly regarded as the most efficient refrigerant available due to it’s low boiling point. To give an example R-717’s boiling point is -28 degrees Fahrenheit. While R-22’s boiling point is -41.62 degrees Fahrenheit and R-410A’s boiling point is -55.3 degrees Fahrenheit. Compare R-717 and R-22 and that’s a forty-eight percent difference in boiling point. Along with that low boiling point you also get no Ozone depletion and a very low Global Warming Potential. I can see why this refrigerant is used but we have to be aware of the downsides. R-717 is toxic and is also slightly flammable. It is rated as a B2L from the ASHRAE group.

Greenwood, South Carolina

Today, March 25th, the Department of Health and Human Services is on the scene of an Ammonia leak in Greenwood, South Carolina. Upon finding the leak and determining how large it was a half-mile radius was evacuated for precaution. Local citizens were awoken by police alerts on their phone and at their door to evacuate the area at two this morning. Later that morning police and firefighters walked through the affected areas taking samples to ensure that the air quality had returned to normal. The all clear was given this morning as well. Luckily, this leak was handled correctly.

While the exact cause of the leak has not been released I did find that it came from a food processing plant known as Carolina Pride Foods. (Their website can be found by clicking here.) This plant is a meat processing and manufacturing center. In the past I have toured a few meat processing plants and just as anyone would assume, they need to be refrigerated as well as have a freezer section. Heck, it’s so cold there you have to wear jackets, mittens, and hoods just to walk around for any matter of time. Using R-717 as their main refrigerant logically makes sense due to the energy efficiency. (In fact you’ll see these used in most industrial applications like this.)

Luckily, with this leak in South Carolina there were no fatalities. However, this latest incident was very familiar to a leak at an ice rink that occurred in Canada towards the end of 2017. A leak occurred and a large radius was evacuated just like in today’s story. The difference though was that proper precautions were not taken in Canada and it resulted in three fatalities. This tragic event has caused a lot of business owners and contractors to reconsider using Ammonia in future applications. I wrote a story about this event that can be found by clicking here.


While today’s event ended well and with no injuries I still am quite skeptical on the reasonable application of R-717. If this stuff leaks, which all systems will at some point, then disaster can occur. Today Ammonia seems to have a monopoly on industrial refrigeration and a fair slice of the market on ice rinks especially over in the European Union. Here’s the thing though, even with it’s danger and risk to public safety the R-717 market isn’t expected to shrink over the next few years. In fact, just the opposite. With all of the pressure around the world to phase out or phase down Ozone depleting or high Global Warming Potential refrigerants the industry has only two options to turn two: HFO refrigerants from Chemours and Honeywell or Hydrocarbons such as Ammonia.

The question on my mind folks is when does saving the environment become more important then safety? Should we keep switching units over to Ammonia in an effort to reduce Global Warming, or should we begin switching to HFC alternatives until a more suitable refrigerant that provides low GWP and is non-toxic arrives into the market place?

I looked through Honeywell and Chemour’s website going over their Solstice and Opteon HFO lines but I did not see anything specifically referencing industrial applications. I’m wondering if the rush to find an alternative to R-717 is on the back burner because it doesn’t actually affect the climate whereas all of the other HFC refrigerants are affecting Global Warming. So, again, I feel like safety is taking a backseat to Global Warming.

Thanks for reading,

Alec Johnson



It’s always sad news when you see a story like this. This came up on my alerts earlier this morning and I felt that I had to take some time and write about it. There have been three confirmed fatalities after an Ammonia refrigeration leak at an ice rink arena in Fernie, British Columbia on Tuesday night. The ice rink and arena is now closed and to top it all off people have been forced to evacuate their business, homes, and even a retirement center due to the leak. The sight is more or less secure now but there are still emergency services on hand along with refrigeration consultants trying to figure out what went wrong. The news article can be found here.

This tragic event happened in the small town of Fernie, British Columbia. Fernie has a population of just over five-thousand and is located just north of Montana. When events like this happen in a small town it amplifies them because you know the victims. You know their families. The town suffers along with the victim’s families. I’m from a small town myself and this hits too close to home. I pray for the town and hope that they can recover quickly.


Ammonia, or R-717, refrigerant is rated as a B on the toxicity scale from ASHRAE. The Class B toxicity signifies refrigerants for which there is evidence of toxicity at concentrations below four hundred parts per million. Most refrigerants in today’s world are rated as an A toxicity, or no danger of toxicity, but there are exceptions out there like R-717 that are still widely used across North America and Europe.

Symptoms of Ammonia poisoning can include coughing, shortness of breath, difficult breathing or tightness in your chest. Severe exposures can cause immediate burning of the eyes, nose, throat, and respiratory tract. Ending results being blindness, lung damage, or even death as in the case in this story.

Way back in the day about one-hundred years ago Ammonia was used widely as a refrigerant. In fact Ammonia is more or less the founding refrigerant. It goes as far back as mid 1800’s when the very basic principles of refrigerant were being tested and theorized. In fact the first Ammonia ice rink goes all the way back to the year 1870 in New York. Along with ice rinks Ammonia was used in a variety of other applications including refrigerators, food processing, and industrial facilities.

In the 1930’s when the coming of R-12 and R-22 Freon began the use of Ammonia in refrigeration and air-conditioning began to lessen as CFCs and HCFC refrigerants provided a non-toxic solution. No one wanted a potential lethal refrigerator in their home.  There were a few industries however such as food, beverage, and chemical  that embraced Ammonia and have stuck with it throughout the past one-hundred years. Chances are that the meat or milk you are buying went through an Ammonia refrigeration system at one point in it’s supply cycle. Besides food and beverage industries ice rinks also stuck with the use of Ammonia. Manufacturers favored it over other refrigerants due to it being the most cost effective and energy efficient refrigerant out there. The downside as I mentioned above is the toxicity. Remember folks, there is no perfect refrigerant. Each one has it’s Pros and Cons.

Over the years R-22 chipped away at Ammonia’s dominance in the ice rink industry as well as food and drink processing. When the phase out of R-22 and other HCFCs were announced alternative refrigerants were introduced into ice rinks such as HFCs R-134a and R-404A. But now, here we are again with HFCs being phased out and 134a and 404A going away. So, what is left for ice rinks besides Ammonia? Is there a safe alternative that will stand the test of time?

CO2 to the Rescue

Carbon Dioxide refrigerant, or R-744, is now starting to compete with Ammonia on the ice rink market as well as many other applications. This is mainly due to the other competitors such as R-404A and R-134a being phased out across the world due to their high Global Warming Potential. That’s not even mentioning the old standby of R-22 which is practically completely phased out. There really wasn’t much left out there folks. I’m waiting for an HFO alternative from Honeywell or Chemours to be marketed towards ice rinks but so far I haven’t found one. (Maybe 1234yf?)

The first CO2 ice rink was installed in 1999. Since then the pace has been very slow. This is mainly due to the efficiency of Carbon Dioxide.  In the 2000’s a R-744 (CO2) ice rink would require fifteen compressors to operate. The Ammonia counter part only needed two. Fifteen compressors to two. The Carbon Dioxide was extraordinary expensive and just impractical. Can you imagine diagnosing that fifteen compressor monster if something went wrong?

The good news is that with most things all it takes is time. Over the years the new and better technology allowed R-744 refrigerant to be more competitive against Ammonia. Now, with each passing year the cost of R-744 refrigeration is shrinking and shrinking. While it is not at Ammonia energy and efficiency levels yet CO2 is non-toxic and the technology is only getting better.

Now, in 2017, there are more and more CO2 ice rinks opening up. Sourcing from Ammonia21.com there are approximately twenty-five to thirty CO2 ice rinks installed and running across the world with twenty of them being in Canada. Europe has been resistant to the change and has still been going strong with Ammonia but here in the United States and in Canada many new arenas have opted for the CO2 refrigeration. I can predict only more CO2 rinks in the future.


It’s hard to say if CO2 will take over the reigns of ice rink and other commercial refrigeration needs or if we will be using Ammonia for decades to come. While I agree Ammonia is a efficient refrigerant I feel that we need to put as much research and money that we can into CO2. It’s a safe, non-toxic, and non environmentally damaging refrigerant. The risk of Ammonia, albeit small, is still there. If it was me I’d worry about toxicity first and then the environment. It’s time we get away from the toxic refrigerants for everyone’s safety.

Thanks for reading,

Alec Johnson