What is Hydrogen Peroxide (H₂O₂) and why can overexposure be harmful?
Understanding the Risks Behind a Common Sterilization Chemical
Hydrogen peroxide (H₂O₂) is widely known as a sterilant used across healthcare, food processing, and industrial environments. In sterile processing departments (SPDs), vaporized hydrogen peroxide plays a critical role in sterilizing medical instruments that cannot tolerate the high temperatures of steam sterilization. However, despite its effectiveness as a sterilizing agent, hydrogen peroxide can also pose significant occupational health risks if exposure is not properly controlled.
Understanding both the benefits and hazards of hydrogen peroxide is essential for protecting sterile processing technicians and maintaining safe hospital operations.
What Is Hydrogen Peroxide?
Hydrogen peroxide is a colorless liquid composed of hydrogen and oxygen (H₂O₂). It is chemically unstable and acts as a strong oxidizing agent, meaning it reacts readily with other substances to break down organic material, including bacteria, viruses, and spores.
Because of these properties, hydrogen peroxide is used in many industries, including:
- Medical device sterilization
- Surface disinfection
- Food and beverage processing
- Textile and paper bleaching
- Environmental remediation
In healthcare, sterile processing departments often use hydrogen peroxide in vapor form to sterilize heat-sensitive medical instruments. The vapor penetrates device surfaces and destroys microorganisms through oxidative damage.
This powerful antimicrobial activity is exactly what makes hydrogen peroxide both valuable and potentially dangerous.
Why Hydrogen Peroxide Can Be Harmful
Although hydrogen peroxide is effective for sterilization, exposure to highly concentrated liquid or vapor can cause significant health effects. The risks arise from its oxidizing chemistry, which can damage human cells in the same way it destroys microbes.
Overexposure to hydrogen peroxide can cause irritation to the skin, eyes, and respiratory tract. Workers are particularly at risk when vapor is released during sterilization cycles or when sterilizer doors are opened. Because of this, personal protective equipment (PPE) is essential in areas where hydrogen peroxide sterilants are used.
Hidden Exposure Risks in Sterile Processing
One challenge with hydrogen peroxide exposure is that it may not be readily detected by workers because it is odorless and colorless at concentrations that can cause both acute and chronic health concerns. This means workers may be exposed without realizing it.
Published studies have shown that significant vapor spikes can occur during sterilization processes, especially when a sterilizer door is opened at the end of a cycle. In some cases, short-term concentrations as high as 40 ppm have been measured, posing potential exposure risks to staff working nearby.
Even brief spikes can increase occupational risk when repeated throughout a workday.
Why Exposure Limits Are Being Reexamined
Traditional occupational safety limits often focus on 8-hour time-weighted averages (TWA). However, real-world sterile processing workflows involve short bursts of exposure rather than constant levels.
Outdated limits may not fully capture these real-world scenarios. Monitoring exposure during routine SPD activities is critical to understanding actual risk.
As a result, updated guidance, such as AAMI ST58:2024, places greater emphasis on protecting staff from sterilant vapor emissions.
Reducing Hydrogen Peroxide Exposure
Healthcare facilities can reduce exposure risks by implementing a combination of engineering controls and monitoring strategies, including:
- Adequate ventilation in sterile processing areas<
- Proper sterilizer maintenance and operation
- Use of PPE for technicians handling sterilants<
- Continuous or real-time hydrogen peroxide monitoring<
- Sterilization technologies that reduce residual vapor emissions
Some sterilization systems also use plasma technology to break down hydrogen peroxide into water and oxygen, reducing residual vapor after sterilization cycles.
The Bottom Line
Hydrogen peroxide is a powerful sterilization tool that helps healthcare facilities protect patients from infection. However, the same chemical properties that make it effective against microorganisms can also pose risks to the workers who use it.
Key takeaways:
- Hydrogen peroxide is a strong oxidizer widely used for sterilization.
- Exposure to highly concentrated hydrogen peroxide vapor can cause both acute and chronic health effects.
- Because it can be odorless at harmful concentrations, exposure may go unnoticed.
- Short-term vapor spikes during sterilization cycles highlight the importance of monitoring and safety protocols.
As sterile processing workloads increase and technologies evolve, understanding and managing hydrogen peroxide exposure will remain a critical component of workplace safety.
This paper was co-authored by Dr. Ivan Salgo, Chief Medical and Scientific Officer at ASP, and Dr. Richard Warburton, Chief Technology Officer at ChemDAQ.