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Sterilization by Heat

Autoclave Steam Sterilizers Are the Best Tool for Sterilizing Body Jewelry, Tattoo Supplies and Piercing ToolsMicroorganisms are a tattoo and piercing shop's worst enemy. Left to their own devices, they would take root in clients getting tattoos and piercings and potentially cause them a host of problems ranging from irritations to infections or worse. As a shop owner, tattoo artist and/or piercing artist, it's your responsibility to protect your clients from harmful microorganisms. To do that, you have to keep your work space properly sterilized at all times.

In Sterilization Methods, our introduction to the various ways microorganisms can be killed, we listed the most common sterilization methods and explained how they all fall into one of two broad buckets: heat-based sterilization methods and non-heat sterilization methods. Since heat-based sterilization is the more practical option for use in tattoo and piercing shops, we'll explore the benefits and drawbacks of each type of sterilization by heat and identify the ones that are most efficient and effective in the paragraphs below.


Ways to Sterilize With Heat

There are five primary heat-based sterilization methods that can be used to kill the microorganisms that thrive in normal temperatures:

  • Flaming
  • Incineration
  • Boiling
  • Application of Dry Heat
  • Steaming

The first three options are only effective sterilization methods in some instances, and never in tattoo and piercing shops. When it comes to sterilizing body jewelry, piercing tools and tattoo supplies, only sterilization by dry heat and steam are proven to be 100% effective means of sterilization.

Sterilization by FlameFlaming Is Not an Appropriate Heat-Based Sterilization Method for Tattoo and Piercing Shops

Flaming is the oldest known sterilization method--the one that kept our ancestors alive and healthy enough to birth and raise children for generations predating science and modern medicine. In those early days, no one knew about microorganisms and the many ways they can infiltrate an otherwise healthy immune system and destroy it. They did, however, discover that meat cooked over an open flame tasted better, and with time, they deduced that fewer people got sick when eating cooked meat.

Flaming can be an effective way of, say, sterilizing a needle at home before removing a splinter. It is not a good way to sterilize a needle before piercing or tattooing someone, though. Even if you managed to kill every organism clinging to a needle with a flame, you'd have to do the flaming in open air rather than a contained environment. That means the needle could pick up new microorganisms in the time between when it's flamed and when it's used, even if that time span is mere seconds.

It's best to purchase EO gas-sterilized piercing needles and tattoo needles. EO gas, or Ethylene Oxide gas, is a non-heat sterilization method used to sterilize products after they're packaged. The paper backing on each needle blister pack is just porous enough to allow the gas to permeate it and sterilize the needle contained within. If the sterilization process is successful, a dot on the packaging turns blue. The needle is then kept sterile until the package is opened or until the expiration date on the packaging passes.

  • Advantages: Flaming is a convenient way of killing many, but not necessarily all, microorganisms clinging to small metal objects, and it can be used to kill all microorganisms in meat.
  • Disadvantages: There's no way to know if 100% of microorganisms have been killed when you flame something like a needle. Also, not everything you need to sterilize in a tattoo and piercing shop can be flamed (e.g. things like acrylic and PTFE body jewelry and rubber bands would likely melt).


When you incinerate an object, you totally destroy it along with any microorganisms clinging to it. Incineration is a good way to dispose of certain types of medical waste and some single-use things, like contaminated paper disposables. You can't safely incinerate disposables or anything else in a tattoo and piercing shop, though.

Incinerators can be very costly, and only highly-trained personnel can operate them. They're high maintenance, too; not properly maintaining an incinerator can result in issues ranging from incomplete cycles to dispelling of poisonous gases. For these reasons, even hospitals and laboratories typically send waste away to be incinerated off-premise, in a proper incineration center.

  • Advantages: Incineration destroys 100% of microorganisms and reduces the volume of waste significantly. It's also the ideal way to prevent contaminated items from being reused.
  • Disadvantages: If you incinerate an object, you completely destroy it. Incinerators are also costly, and not just anyone can operate them. You have to fuel an incinerator to use it, which adds to the cost. Incinerators also have to be repaired frequently and require constant maintenance.

Boiling as a Sterilization Method

There are a variety of materials that can withstand boiling. Metals and PTFE can all be partially sterilized this way, but it's not a 100% effective sterilization method. It may be the only method a person can utilize at home to sterilize their body jewelry, but it is not an appropriate way to sterilize tools and jewelry in a tattoo and piercing shop.

Boiling works on microorganisms by changing the physical properties of proteins, causing them to coagulate and stop functioning. Think about an egg that's been submerged in boiling water--how the innards coagulate to form a tasty hard-boiled egg that's safe to eat, unlike it was prior to boiling it.Water Boiling in a Beaker

Utilizing boiling as a sterilization method requires adjusting temperatures for altitude, adding washing soda at just the right concentration, covering the container in which water is being boiled, and boiling the object(s) within for a minimum of 30 minutes. Even then, you can't be sure you've killed 100% of the microorganisms clinging to the object(s) you're boiling. Some microorganisms are heat-resistant, like endospores, which can require 20 hours or more of boiling to completely kill. There are also a variety of microorganisms that haven't been researched enough yet to know how long it would take to kill them with boiling water, or if boiling water would kill them at all. That renders boiling a completely ineffective and inappropriate method for sterilizing piercing tools, tattoo supplies and body jewelry.

  • Advantages: Boiling utilizes moist heat, which penetrates materials more quickly than dry heat because air doesn't conduct heat as well as water. It also requires lower temperatures and less time to boil an item than to sterilize it via dry heat.
  • Disadvantages: You can never know if you've killed 100% of the microorganisms clinging to an object you've boiled, even if you boil it for 20+ hours. It just isn't a practical or safe sterilization method for a tattoo and piercing shop to use.

Dry Heat SterilizerApplication of Dry Heat

Dry heat sterilization requires raising the temperature of an object to a controlled 170° Celsius (338° Fahrenheit) for at least one hour to kill all microorganisms clinging to it. Dry heat is the ideal way to kill microorganisms attached to fats, oils and powders, which can't be sterilized in an autoclave because they either resist water or are destroyed by it. That's why an oven is the perfect place to cook meat, which contains fats and oils that can be penetrated by the dry heat an oven emits.

It is possible to purchase an electric dry heat sterilizer for your tattoo and piercing shop. However, it may not be the ideal way to sterilize body jewelry, tattoo supplies and piercing tools for several reasons. First, dry heat sterilizers have to run for at least an hour to kill all microorganisms, which is too much time when you have a client waiting to be tattooed or pierced. Second, you can't effectively sterilize things in bulk in a dry heat sterilizer, since a cluster of objects may prevent air from flowing around each item in the manner needed to bring it's core temperature up to a consistent 170°C. Finally, dry heat is less efficient than moist heat energy-wise.

  • Advantages: Fats, oils and powders that can't be sterilized with moist heat can be sterilized with dry heat. A dry heat sterilizer is typically cheaper than an autoclave in terms of the initial investment, and it's a safe and effective method for sterilizing most tools and body jewelry in a tattoo and piercing shop.
  • Disadvantages: Dry heat sterilizers require higher temperatures and more time to sterilize tools and body jewelry than do autoclaves, or steam sterilizers. They're also more likely to damage tools, and their heating elements tend to break more quickly than autoclaves' heating elements do. Plus, you can't sterilize as many things at once in a dry heat sterilizer. That means you'll spend more money on energy to sterilize shop supplies, you can't serve as many clients in a day as you could if you used an autoclave, and you'll likely face repair costs sooner than you would with an autoclave.

    Whatever you save by buying a dry heat sterilizer instead of an autoclave will likely be eaten up in energy bills and lost business within mere weeks of purchasing it.

Sterilization by SteamAutoclave Steam Sterilizers

An autoclave is the most effective tool for sterilizing tattoo supplies, piercing tools and body jewelry. It utilizes steam under pressure to kill microorganisms on a variety of surfaces ranging from metal to PTFE quickly and efficiently. Autoclaves require less time and energy to run than dry heat sterilizers, making them the ideal tool for high-volume tattoo and piercing shops that need to move clients through at the fastest pace possible.

A steam autoclave that's run at 121°C kills all microorganisms within 15 minutes. This is possible because steam transfers heat more efficiently than anything, including dry heated air and boiling water. Water in general is more effective at transferring heat than anything else, but steam is the most efficient form of water to use to transfer energy. Here's why:

Within the contained environment of an autoclave, steam penetrates the object(s) being sterilized deeply thanks to its ability to condense. Whatever you're sterilizing, it's initially colder in temperature than the steam around it, so it attracts and collects condensation as steam is released. As the steam condenses, it shrinks in volume, creating a suction-like effect that draws even more steam towards the object(s) being sterilized. Throughout this process, the steam penetrates any microorganisms clinging to the object(s) being sterilized. As the microorganisms become fully saturated, their core temperature rises, cooking and then obliterating them.

  • Advantages: Steam is the fastest, most efficient way of sterilizing body jewelry, tattoo supplies and piercing supplies. It requires less energy to run an autoclave steam sterilizer than it does to run a dry heat sterilizer, it can sterilize more items at a time, and a broader range of materials can be placed in an autoclave without fear of them melting, since steam sterilizes objects at a lower temperature than dry heat.
  • Disadvantages: Autoclaves typically require a more significant initial investment than dry heat sterilizers. However, they make up for that initial higher cost by saving money over time. Your energy bills will be lower than if you had a dry heat sterilizer, the heating elements are likely to last longer, and you can see more clients in a day since it takes less time to sterilize piercing supplies, tattoo tools and body jewelry in an autoclave.


No Heated Debate Required

Of all the heat-based sterilization methods, sterilization by steam is by far the best option for tattoo and piercing shops. Dry heat is always an alternative, but it's more likely to cost you money in the long-run. You'll spend more on energy bills, you won't be able to see as many clients in a day, you'll likely have to repair or replace it sooner than you would an autoclave, you won't be able to sterilize objects in as many materials, and you're more likely to damage tools in a dry heat sterilizer. It doesn't require a heated debate to declare a winning heat-based sterilization method; sterilization by steam gets the blue ribbon every time.


More Sterilization Information

This article on sterilization by heat is part of a 6-part Sterilization Series. You can get an overview of all sterilization methods, learn more about sterilization by steam specifically, gain a better understanding of the different sterilization classes, or learn about affordable sterilization alternatives for smaller tattoo and piercing shops by reading our other Sterilization Series articles below.