Both ethylene oxide (EtO) sterilization and plasma sterilization are widely used methods for sterilizing medical devices, but they have different safety profiles and applications. Here’s a comparison to help understand the relative safety of each method:

Ethylene Oxide (EtO) Sterilization
Advantages:
Effectiveness: Highly effective at killing a wide range of microorganisms, including bacteria, viruses, fungi, and spores.
Compatibility: Suitable for a variety of materials, including plastics, rubber, and electronics that cannot withstand high temperatures or moisture.
Penetration: Excellent penetration capabilities, making it ideal for complex devices with lumens or intricate parts.
Disadvantages:
Toxicity: EtO is toxic and classified as a carcinogen. Direct exposure can cause respiratory irritation, headaches, nausea, and long-term health effects.
Residuals: Requires thorough aeration post-sterilization to remove residual EtO gas from the products.
Environmental Impact: Strict regulations are in place to control emissions due to its environmental impact.
Plasma Sterilization
Plasma sterilization typically uses hydrogen peroxide vapor that is activated by an electric field to create reactive plasma species that kill microorganisms.

Advantages:
Safety: Generally considered safer for both operators and patients because it does not leave toxic residues on the sterilized items.
Speed: Faster cycle times compared to EtO sterilization.
Environmentally Friendly: Produces water vapor and oxygen as by-products, which are harmless to the environment.
Disadvantages:
Material Compatibility: Not suitable for all materials; some plastics and certain types of rubber may be damaged by the process.
Penetration Limitations: Less effective at penetrating long lumens or complex device geometries compared to EtO.
Safety Comparison
For Operators:
EtO Sterilization: Requires stringent safety measures such as proper ventilation systems, personal protective equipment (PPE), leak detection systems, and strict adherence to regulatory guidelines due to its toxicity.
Plasma Sterilization: Generally safer for operators as it does not involve handling toxic gases; however, appropriate safety measures should still be in place.
For Patients:
EtO Sterilization: Residual EtO must be thoroughly removed through aeration processes before the product is safe for use on patients.
Plasma Sterilization: Leaves no harmful residues on sterilized items, making it inherently safer for patient use immediately after processing.
Regulatory Compliance
Both methods are regulated by agencies such as the FDA (U.S.), OSHA (Occupational Safety and Health Administration), EPA (Environmental Protection Agency), and international standards organizations like ISO:

Regulations ensure that both EtO and plasma sterilizers meet stringent safety criteria regarding effectiveness and operator/patient safety.
Summary
While both EtO and plasma sterilizations are effective methods with their own advantages:

Plasma sterilization is generally considered safer due to its non-toxic nature and lack of harmful residues.
However, EtO remains indispensable for certain applications due to its superior penetration capabilities and material compatibility.
The choice between these two methods often depends on specific application requirements balanced against safety considerations for both operators and patients