Oxygen-carrying medical electrical equipment represents a critical intersection of necessity and risk. While these devices can save and improve countless lives, they also present unique safety challenges that manufacturers must understand and address.

In this article, Nic Linley, Senior Electrical Engineer at WHA International, Inc., offers guidance on understanding and achieving compliance following recent updates to the international safety standard IEC 60601-1:2020.

The Importance of Oxygen in Oxygen-Carrying Medical Electrical Equipment

Oxygen-enriched environments—defined by IEC 60601-1 as anything containing more than 25% oxygen at atmospheric pressure—create conditions where materials can become dangerous fuel sources. Even materials that perform well in normal air may readily burn in oxygen-rich conditions.

In the United States, the FDA requires manufacturers to meet IEC 60601-1 standards to access the market. Healthcare facility codes, such as NFPA 99, mandate that oxygen delivery equipment must be listed for use in oxygen-enriched atmospheres in accordance with these standards.

Of course, the consequences of failing to address these risks extend beyond regulatory compliance. Patient safety, corporate liability, brand reputation, and market access all hang in the balance.

How do these standards work? Let’s take a look.

Understanding the Framework

The IEC 60601-1:2020 provides a comprehensive framework for ensuring the safety of medical electrical equipment used with oxygen.

The standard outlines four distinct pathways for manufacturers to demonstrate compliance (subclause 11.2.2.1 b):

1. Manufacturers can show that both thermal and electrical energy levels are adequately limited within their equipment. They must not be able to generate sufficient heat or electrical energy to cause ignition.
2. They can demonstrate that their equipment’s ventilation system effectively prevents oxygen concentration from exceeding 25%, with adequate fault detection systems in place.
3. They can establish appropriate maintenance intervals, including regular inspection for potential oxygen leaks and other hazards.
4. They can conduct compartment fire testing to prove that even if a fire occurs, it will self-extinguish without propagating or releasing dangerous levels of toxic gases to the patient.

The Path to Compliance

Achieving compliance requires a systematic approach to testing and validation. Working with an oxygen safety expert like WHA International, manufacturers can implement comprehensive testing programs that address potential risk pathways, selecting the most suitable path for each situation.

The framework first considers the device design to identify all compartments potentially containing elevated oxygen levels, either by design or by failure modes such as a leak. Each compartment must show compliance with one of the four pathways mentioned above.

A variety of specialized oxygen tests may be required to demonstrate compliance. These can include:

• Autogenous ignition temperature (AIT) testing can indicate the temperatures at which materials may ignite in oxygen-rich environments. Since IEC 60601-1 does not provide guidance to establish the ignition temperature of a material, WHA recommends the guidance of ASTM G88 section 7.3.4, and testing the material against ASTM G72 section 8.2.3. In this test, a small sample of the material is installed in a test chamber pressurized with gaseous oxygen, and the chamber is heated until ignition of the material is detected.
• Drawn arc (or “spark”) testing helps evaluate ignition risks from electrical components. The test exposes a material sample to an electrical arc within an oxygen-rich environment. The material is exposed to the drawn arc 300 times, and if the material ignites, then a potential source of ignition exists.
• Finally, Compartment fire testing may be used to validate safety systems in case of a fire. If device manufacturers cannot sufficiently limit the risk of ignition, they must demonstrate that if a fire does occur, it safely self-extinguishes without propagating to the rest of the device or exposing the patient to toxic gases. The compartment fire test must be staged under the foreseeable worst-case scenario that an operator might encounter.

Case Examples

WHA’s experience in oxygen-carrying medical devices is based on over 30 years of hands-on testing and failure analysis experience. The following case examples demonstrate how WHA’s expertise has been applied to solve complex oxygen-related safety issues in medical devices.

Example 1: Advanced Failure Analysis Prevents Recurrence of Ventilator Fires

When a critical care ventilator manufacturer faced multiple field incidents involving smoke emission during patient use, WHA’s forensic investigation revealed that bearing failure in the turbine motor led to mechanical overheating and ignition of surrounding sound-dampening foam in an oxygen-enriched environment of the turbine (blower) box. Through systematic disassembly, analysis, and operational testing, WHA pinpointed the exact ignition sequence and oxygen pathway that created the hazardous conditions.

This comprehensive investigation enabled WHA to provide the manufacturer with targeted recommendations, including higher oxygen-index materials for key components, enhanced thermal protection around the blower assembly, and specialized ignition resistance testing protocols for worst-case oxygen exposure scenarios—translating the complex results of the failure analysis into practical safety solutions that protect both patients and manufacturers.

Example 2: Creative solutions for robust leak prevention and testing

A leading manufacturer of humidified respiratory devices sought to ensure that their blower motor assembly remained resistant to oxygen enrichment, a critical factor in preventing ignition hazards in oxygen therapy environments. WHA developed a customized testing program to verify the effectiveness of a silicone-based potting material as a protective barrier against oxygen ingress, while also evaluating its resilience under worst-case failure conditions. The testing was consistent with the intent of the compartment fire test in IEC 60601-1 11.2.2.1b 4).

Through comprehensive fault tree analysis and rigorous testing, WHA confirmed that the silicone potting compound effectively contained potential ignition events and prevented oxygen resupply. By combining advanced failure analysis with targeted testing, WHA enabled the manufacturer to confidently validate the safety of their blower assembly, ensuring compliance with IEC 60601-1 safety standards while reinforcing their commitment to patient safety.

Example 3: WHA utilizes quantitative risk analysis to support hazard analysis

A medical device manufacturer developing a humidified respiratory system required a failure rate analysis to assess potential electrical ignition risks. WHA International applied probabilistic risk assessment (PRA) methodologies to quantify the likelihood of ignition sources in an oxygen-enriched environment. The goal was to support hazard analysis, ensuring compliance with IEC 60601-1 safety standards.

WHA conducted a detailed review of critical electrical components, generated failure rate estimates using 217Plus™:2015 models, and performed Monte Carlo simulations to evaluate failure rate uncertainties at a system level. The analysis incorporated potential leak rates that could lead to oxygen enrichment inside the electronics compartment and calculated combined probabilities of electrical failures coinciding with an oxygen-rich atmosphere.

WHA’s quantitative approach provided the manufacturer with a robust risk assessment, leading to improved sealing around electronics, optimized maintenance schedules, and empirical reliability data to demonstrate compliance with IEC 60601-1’s specific oxygen requirements. By leveraging quantitative risk analysis and advanced simulation techniques, WHA enabled the manufacturer to confidently validate their device’s safety, ensuring patient protection in oxygen therapy applications.

Making Informed Decisions

For business leaders and decision-makers, understanding these requirements isn’t about mastering technical details—it’s about making informed choices about resource allocation, risk management, and product development strategies. Key considerations should include:

Early Integration: Safety considerations should be built into product design from the earliest stages, not treated as an afterthought. This approach is both more cost-effective and more likely to result in successful compliance.

Expert Partnership: Working with experienced oxygen safety specialists like WHA International can help navigate complex requirements and avoid costly missteps. Their extensive experience in investigating oxygen-related fires provides unique insights into potential failure modes and effective prevention strategies.

Comprehensive Testing: Comprehensive testing programs provide the strongest protection against both safety incidents and regulatory issues.

Looking Ahead

As medical technology and home healthcare continue to advance, the importance of oxygen safety will only increase. Companies that understand and prioritize these requirements position their organizations for success while fulfilling their fundamental obligation to protect patient safety.

As healthcare delivery becomes increasingly home-based, medical equipment must be even more foolproof. Equipment that might once have been used only by trained professionals in controlled hospital environments may now be operated by patients or caregivers in home settings.

WHA International stands ready to assist manufacturers in meeting these challenges, offering both testing services and deep expertise based on decades of experience in oxygen safety.