How Permanent Makeup Needles are Sterilized

If there is just ONE thing that is not optional in the permanent makeup industry, it is sterilizing needles.  There are two methods for sterilizing needles: gamma ray and EO gas. Find out what goes into each method and why sterilization matters. 

Gamma ray

Gamma sterilization uses radiation to kill microorganisms. The main advantage is the high penetration capability. It works best when the material allows radiation to travel through, such as clear plastic. This also ensures that harmful residue won’t be left behind. Gamma ray works with sealed products as well as both dry and moist materials. 

The process includes the following steps: 

1. Sealing the instrument in an air-tight bag.
2. Placing the bag in a field of radiation that can penetrate the bag to kill bacteria.
3. Keep the sterilized instrument in the air-tight bag until it’s used.

The turnaround time for this method is quick. Gamma ray is used for many single-use, disposable devices including PMU instruments.

EO gas

EO stands for Ethylene Oxide. This gas disrupts the DNA of microorganisms and prevents them from reproducing. However, in order for the gas to travel through to kill any bacteria, the sterilized product needs to have openings. To sterilize, products are exposed to EO gas under vacuum in a sealed chamber. The process works with most materials such as plastics, metals and gas. The more complicated the design is, the longer it takes to be sterilized and the higher the possibility of leaving gas inside the product.

EO sterilization controls four variables: gas concentration, humidity, temperature and time. The process includes 3 main phases:

1. Pre-conditioning: Preheat and humidify products. This ensures EO sterilization can work regardless of pre-processing storage conditions. 
2. Sterilization: The load is exposed to a required level of EO gas for that device or family of devices.
3. Aeration: To accelerate outgassing of exposed product loads and to contain and eliminate residual EO emissions

Some notes if you use EO gas sterilization: EO Gas requires a special type of packaging material that allows the gas to penetrate through. A lot of plastic bags are not compatible with EO Gas. The bag needs to be vented so they can inflate (and won’t burst.) This means sealed aluminum pouches cannot be exposed to EO. 

Shop needles on MEI-CHA! Make sure you get sterilization certificates for your needles wherever you shop for them.