70% IPA (ISO) is more effective for cleaning your herbal vaporizer than 99% IPA: Why Less is More, According to Science

70% IPA (ISO) is more effective for cleaning your herbal vaporizer than 99% IPA:  Why Less is More, According to Science

Onsen Labs is in the business of manufacturing and marketing dry herb vaporizers and accessories. Our research provided herein is for the benefit of our customers in the cleaning of their Onsen Labs equipment.  

by Gaurav Dubey (MS Biotechnology)

Optimizing your herbal vaporizing experience will almost certainly entail routine and proper maintenance of your equipment. Be it dab rigs or dry herb vaporizers, the time and need to clean and disinfect your devices will inevitably arise. Like most things in the herbal multiverse, such a task generally does not come with detailed, evidence-based instructions. The general consensus and practice is to use alcohol for such a purpose. More specifically, the best candidate among the various types of alcohols is IPA or isopropyl alcohol (not to be confused with the deliciously malty adult-beverage, india pale ale aka “IPA”). Culturally our community refers to this as “ISO”, however the prefix “iso” refers to the molecular structure of various different types of alcohol, not just isopropyl alcohol. As a result, for the sake of accuracy, we will refer to isopropyl alcohol as IPA in this blog. 

But is IPA (ISO) really the best candidate for the job and if so, why? Additionally, IPA comes in different concentrations depending on the amount of purified water it was diluted with (excluding 99% IPA). Herbal aficionados generally reach for the highest purity (~99%) product, assuming it will be the most efficacious at killing bacteria and cleaning their device. But is this really the case? While 99% IPA may be more effective at removing large, globs of oil deposits, however, for optimal disinfection and long-term vaporizer maintenance, 70% IPA has shown to be the most efficacious. In this blog, we will explore the science behind why this is true. A closer, scientific look at this question ends up revealing a rather curious phenomenon: less (IPA) is more when it comes to the optimal IPA concentration for disinfection. 

This article will dive into the scientific reasoning behind the use of isopropyl alcohol as a disinfectant and why 70% IPA is actually a more effective cleaning agent than 99% IPA. Adequate and routine cleaning and maintenance of herbal vaporization devices is critical to cultivate a successful and efficacious experience for maximal health and wellbeing. The idea behind this piece is to further inform and educate the community on how to best do that.

The Benefits of Alcohol as a Disinfectant and Cleaning Agent

Alcohol has been used as a disinfectant and antimicrobial cleaning agent for many, many years. This is especially true in the healthcare and scientific industries and has been particularly prevalent in hospitals and laboratories for many years. It has become standard practice in fact for physicians to use an alcohol-based disinfectant on their hands after finishing with their previous patient and before engaging with their new patient. 

The same is true for the biologist working with cells in a “chemical hood” who is constantly in need of disinfecting the materials they are using. While this may not be a big surprise to the average reader, it is worth posing the question inquiring as to why alcohol of all chemicals is the preferred disinfecting agent today and, given the varying formulations and types of alcohol, which one is the most effective at eliminating harmful bacteria, fungi and viruses along with exploring the scientific reason as to why that is the case.  

What is Isopropyl Alcohol or IPA?

Isopropyl Alcohol (also known as 2-propanol or IPA for short) is one of the most commonly used disinfectants with a vast variety of industrial applications. IPA is used in hospitals, pharmacies, medical device manufacturing plants and other areas that require a sort of “clean room” due to various bureaucratic regulations as well as varying customer needs and demands. 

IPA is one of many alcohol-based solutions, each of which vary along a spectrum of purity and have unique properties that provide varying benefits when correctly used as a cleaning and disinfecting agent. Generally, IPA solutions are somewhere between 60-90% alcohol. All isopropyl alcohol graded under 99% is diluted with 10-40% purified water to create more dilute solutions. As this piece continues to explore the science behind IPA as a disinfectant, the counter-intuitive benefits of partially dilute IPA versus 99% IPA will be discussed. 

In the world of herbal vaporizers, repeated use of smoking and/or vaporization devices will eventually require adequate cleaning and disinfecting to optimize the experience for maximal health and wellbeing. The need to eliminate harmful bacteria in such devices is crucial, as is the proper knowledge on how to do so. 

Less Is More: Why 70% IPA is the Most Superior Concentration for Disinfection

It’s certainly a natural assumption to believe that stronger concentrations of alcohol would be increasingly more effective at killing pathogens and unwanted microorganisms. This, however, is simply not the case. Studies have shown that 70% IPA is actually far more efficacious at eliminating harmful microorganisms such as bacteria, fungi and viruses than 99% IPA. 

The reason that strong but still dilute concentrations of IPA are deemed the most effective disinfectants and antimicrobials is in fact not due to the alcohol itself, but to the purified water it is diluted with instead! Scientists have found that 70% IPA is the most ideal for these applications as it contains the optimal balance between IPA and water. But why is water necessary in the battle against bacteria and other harmful microorganisms? 

The answer is complex yet fascinating as the optimal presence of water in IPA opens the door to several novel mechanisms that demonstrate antimicrobial, antiseptic and antifungal activity that simply cannot be exhibited by pure 99% IPA. 

Novel Mechanisms by Which Water Boosts the Disinfectant Properties of IPA

Water Denatures Pathogenic Cell Membranes By Acting as a Catalyst

When utilizing isopropyl alcohol as a disinfectant, the role of water in diluted concentrations cannot be overlooked. In fact, the water used to dilute various concentrations of IPA plays a crucial role in destroying and inhibiting the growth of pathogenic microorganisms by effectively acting as a catalyst in denaturing (or destroying) the proteins used to make up the cell membranes of pathogenic cells in a vegetative state. 

The cell membrane is its “outermost layer” and is composed of proteins that help the cell retain its structure, provide protection from the external environment and facilitate the transport of molecules inside and outside the cell (among other vital functions). The presence of water essentially breaks down these walls, the pathogenic cells first line of defense. This allows for the 70% IPA to penetrate the cell wall more completely and permeate the cell more fully, coagulating the proteins and causing the microorganism to die. 

More Water Equals Slower Evaporation Times & Greater Surface Contact Time

In comparison to 99% IPA, which contains virtually no water, the extra water content in 70% IPA results in slower evaporation times as water evaporates much slower than pure alcohol. As such, this allows for greater surface contact time thus enhancing the ability of the IPA to permeate the entire cell and coagulate all the proteins and neutralize the microorganism. On the contrary, IPA above 91% in concentration instantly coagulates proteins, which results in the formation of a protective layer that protects other proteins from further coagulation.1 This is yet another established mechanism by which 70% IPA is more effective than 99% IPA as a disinfectant.

70% IPA Is Less Likely to Explode Than IPA that is 91% and Up

It should come as no surprise that alcohol is an incredibly flammable substance. A 70%/30% IPA solution produces less vapor and less odor than higher concentrations of IPA. This is a critical benefit as the risk of generating toxic fumes and combustion is also significantly lowered. When IPA is exposed to air, light and oxygen, volatile free radicals form which increase the likelihood of explosion. Over time, higher concentration IPA that is stored becomes even more volatile, especially when exposed to light after opening. As such, working with slightly more dilute forms of IPA is magnitudes safer than attempting to handle highly concentrated IPA. Additionally, 70% IPA is slightly little more affordable than those that are 91% and greater (about 3.3% cheaper, so nothing too crazy!). This is particularly useful when it comes to large surface disinfection. Overall, the safety profile and price point of 70% IPA, in addition to its aforementioned superiority as an efficacious disinfectant, make it a significantly more appealing choice as a disinfectant than highly concentrated IPA formulations. 

A Brief Note Regarding Safety

In following up on the previous paragraph, it’s worth restating what is likely obvious yet important advice: alcohol should be handled with caution, as it is an extremely flammable substance. The higher the alcohol concentration of IPA, the more flammable it is due to the reasons mentioned earlier. While handling lower concentration formulations of IPA decreases the risk of combustion, there are other key factors to remember when utilizing IPA as your disinfectant: 

  • Always handle IPA in a well-ventilated area
  • Thoroughly rinse and dry your herbal vaporizer before activating the heating element or taking a heat source to it. 
  • Open stored bottles of IPA away from excess light 
  • Always handle IPA with caution 

Sterilization Versus Disinfection

The CDC defines sterilization as being sporicidal whereas disinfection does not have sporicidal attributes. Some bacteria, under conditions of extreme stress, will reduce their metabolic activity and transform from a vegetative state into spore cells, thus increasing their immunity to alcohol-based disinfectants. While IPA has been shown to intermittently be effective at eliminating fungus, it cannot exhibit sporicidal properties and, as such, is not considered a sterilizing agent but a disinfecting agent instead. 

Can I Use Scotch Whiskey (Ethanol) as My Primary Disinfectant Instead?

All forms of alcohol have beneficial disinfectant properties. Indeed, the same is true for the recreational, commonly consumed form of alcohol known as ethanol. In fact, popular forms of ethanol such as scotch and whiskey do have some favorable antiseptic properties and is likely the reason it has been effectively used when more ideal options, such as IPA, are unavailable. However, unlike more effective disinfecting agents such as IPA, the low volume of alcohol in scotch and whiskey would take several hours to do the job of killing certain bacteria and microbes such as gas gangrene. 

In fact, eliminating such agents such as gas gangrene would take up to 18 hours with scotch whiskey. On the flip side, a 50% ethanol solution would only take, on average, 15 minutes to kill E. coli bacteria and only 45 minutes to eliminate streptococcus bacteria in a “cooked-meat broth”. Even more interesting is the fact that scotch whiskey only needs 20 seconds to wipe out pneumonia and strep on a glass thermometer.2,3 Isopropyl alcohol is far superior for rapidly and completely eliminating such unwanted microbes due to its chemical structure and high volume alcohol content.  

Not only do these results speak to the benefits of ethanol and more generally, alcohol as an effective disinfectant, these findings also help illustrate the nuanced and complex versatility of different bacterial, viral and fungal agents and the significant variation each one presents with respect to neutralizing them. When it comes down to selecting the best disinfecting agent (in particular, for your herbal vaporization device), the science claims it’s best to leave the recreational booze in your glass and reach for the IPA instead. Since such devices generally require the individual to inhale smoke or vapor through the instrument, utilizing the best cleaning agent to most effectively eliminate bacteria, viruses and fungi as best as possible are ideal for a healthy, safe and optimal herbal vaporizing experience.  

Do I Really Need To Clean My Herbal Vaporizer?

Short Answer? Yes, absolutely! All materials, even glass, can absorb “junk” from the air in their surroundings, at least in the few micron layers depending on material composition. When it comes to inhalation as a route of administration, it is important to understand the lungs do not exhibit the same level of “filtration” as the stomach and liver do, for example, when herbal remedies are consumed orally. As such, the need for adequate disinfection of vaporization devices prior to inhalation is crucial for adequate hygiene! 

Why Good Hygiene for Dry Herb Vaporizers Is Important

One particularly interesting analogy is that of washing one's dishes to remove the dirt and food from yesterday as to not tarnish or taint of the flavor of our meals the next day. Indeed, eliminating the buildup of oils and particulate matter on the sides that line vaporization devices is critical for the optimal physiological experience and flavor profile. This becomes further true when considering the fact that saliva from our mouths combines with the oil from past sessions in these devices. Unlike oil cartridges and disposable vape pens, which are disposed of with the mouthpiece after completion, quality dry herb vaporizers are investments to be used and well-maintained for many years to come. 

The Desktop Pro: High Quality Experience for the Hygiene Minded Enthusiast

At Onsen Labs, we’ve utilized the evidence-based application of advanced thermodynamic and engineering principles to create a high-quality, easy to clean dry herb vaporizer for hygiene minded people. Our vaporizer features high quality materials including 99.8% alumina oxide (Al2O3), unreinforced medical grade peroxide cured silicone tubing, grade 2 titanium and, depending on the model, a heat shield featuring either a poly-carbonate (clear plastic) or borosilicate glass heat shield. The Desktop Pro utilizes the clear plastic heat shield while the Desktop Pro Elite model features a borosilicate glass heat shield and also comes with a carbon, smell-absorbing bag. These high grade and inert hot zone material properties help minimize unpleasant offgassing and side reactions. 

Closing Thoughts

Sometimes, less is more. When it comes to finding the best solution to clean your herbal vaporizer, the science says 70% IPA is superior to solutions concentrated at 91% and above. So next time you want to clean your herbal vaporizer, put your bottle of whiskey away and reach for a better solution (pun intended)!

Works Cited

  1. Why Is 70% Isopropyl Alcohol (IPA) a Better Disinfectant than 99% Isopropanol, and What Is IPA Used For? Production Automation Station https://blog.gotopac.com/2017/05/15/why-is-70-isopropyl-alcohol-ipa-a-better-disinfectant-than-99-isopropanol-and-what-is-ipa-used-for/ (2017)
  2. Can liquor be used as an emergency antiseptic? – The Straight Dope. http://www.straightdope.com/columns/read/2978/can-liquor-be-used-as-an-emergency-antiseptic/
  3. Block, S. S. Disinfection, Sterilization, and Preservation. (Lippincott Williams & Wilkins, 2001)


1/8/2020: Edits made to reference the cultural vs scientific use of 'ISO' vs IPA and IPA vs india pale ale, and the use of 99% IPA for large globs vs disinfectant properties. 

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