Hydrocarbon Refrigerants and Risk

This month’s SSGM has an article about a subject that has stirred controversy across the repair aftermarket: hydrocarbon refrigerants. Yes, it’s the middle of winter, but I’ve written it in February to get this issue out there before the spring rush to prepare for the summer A/C season. For the few of you who don’t know what hydrocarbon refrigerants are, they’re normally blends of propane and butane that act as drop in replacements for R12 or R134a in automotive A/C systems. The other thing they are is controversial. No one seems to have a neutral opinion about HC refrigerants. I’ve tested them in my personal car, and yes, they perform well. I’ve also had them removed and replaced with R-134a by people concerned about my safety. Both the tech who put the HC in and the one who took it out were trained, competent techs, and both had lots of experience. One reported years of use with lots of happy customers and no problems. The other regarded the products as accidents waiting to happen. Part of the problem is the way we assess risk in our culture in general. Unfortunately, the public, and we in the media are partly to blame here, want to know whether or not a product is “safe”. The reality is that safety is always a relative term, so the real question should be, what is the acceptable level of risk for this product? When we’re immunized against a disease, there’s a small chance that we’ll get sick, maybe even die. It’s worth it to get the protection against the disease, given the small chance that the shot will make us sick. But it could happen. Researchers use tools like qualitative risk assessment to generate numbers like “3.5 x 10 -7” which is meaningless to most people. It’s better described as “one in three million” but even that is difficult to assess objectively. For some reason, the “struck by lightning” scale seems the most popular. If the risk is of the same order as the chance of being struck by lighting, most people assume it to be safe. I saw a recent stat that said that over a driving lifetime in Europe, the chances of being injured in a car accident are about one in a hundred. That’s one percent, which is about three thousand times more likely than the number I quoted above. What does this mean? At its simplest, it means that the riskiest aspects of driving are so much more likely than safety issues such as the type of refrigerant you use or the brand of brake fluid in the master cylinder that we have to prioritize what we worry about and what we don’t. Personally, I’ll accept 12 ounces of propane in my air conditioning system, but I won’t install white box ride control or brake components. Brake failures are very rare today, even with the giveaway garbage brake friction out there, but I perceive the risks to be too great, so I spend a little more. I also perceive that the likelihood of a fractured evaporator venting enough HC refrigerant into the passenger compartment of my car to be small enough that I’ll accept blends in my long-suffering Dodge Caravan. You may choose differently, and so may your customers. Keep in mind, though, that nothing is “safe”, or “unsafe”. Everything is a risk; knowing the level of risk is where wise choices begin.