SF2H Recommendations: Air Quality, CO₂, and the Prevention of Healthcare-Associated Infections

May 29, 2026

Why the 2024 SF2H Guidelines Marked a Turning Point in the Prevention of Healthcare-Associated Infections

The Recommendations for the prevention of respiratory transmission of infectious agents in healthcare settings published by the SF2H (French Society of Hospital Hygiene) in October 2024 marked a significant shift in the consideration of indoor air quality in healthcare facilities.

In addition to standard precautions and personal protective equipment, these recommendations now emphasize the importance of ventilation, air exchange, room ventilation, monitoring of isolation measures, and indoor environmental testing in the prevention of healthcare-associated infections (HAIs), formerly known as nosocomial infections.

This development is a direct result of the lessons learned from the COVID-19 pandemic and a better understanding of the airborne transmission of certain infectious agents.

Today, prevention no longer relies solely on individual behavior. Controlling indoor environments is gradually becoming an additional tool for ensuring the safety of healthcare settings, and it always begins with a step that is too often overlooked: measuring before taking action.

Elderly people receiving care from medical staff

Air Quality and Respiratory Transmission: Key Takeaways from the SF2H Recommendations

The recommendations from the French Society of Hospital Hygiene note that certain areas can promote the accumulation of respiratory aerosols when air exchange is insufficient: patient rooms, waiting rooms, treatment rooms, reception areas, meeting rooms, and break rooms.

In hospital settings, respiratory transmission is a major concern for both patients and healthcare professionals.

Indoor air quality thus becomes a cross-cutting issue that encompasses the prevention of healthcare-associated infections, occupational health, occupant comfort, building performance, and the management of airborne risks.

The recommendations therefore emphasize the importance of proper ventilation, adequate air exchange, and better management of lockdown situations.

Why measure CO2? What are dangerous CO2 levels in ppm? What is the maximum CO2 level in a room or in the air?

Why is CO₂ becoming a key indicator in healthcare facilities?

One of the key changes in the SF2H guidelines is the use of CO₂ as an indicator of indoor air quality.

Carbon dioxide (CO₂) cannot be used to directly measure the presence of viruses or bacteria in the air. However, it serves as a simple indicator for indirectly assessing air exchange, actual occupancy of the premises, and the potential accumulation of exhaled aerosols.

SF2H Recommendation R5 states that it is strongly recommended that fresh air supply rates be sufficient to maintain a CO₂ level in occupied spaces below 1,300 ppm, and if possible, below 800 ppm. This 800 ppm threshold is also the maximum level set for rooms housing patients at high risk of infection.

In its commentary on Recommendation R3, the SF2H also highlights the value of using CO₂ sensors (permanent or temporary) to verify a room’s ventilation parameters, in addition to other tools such as anemometers or flow meters.

Monitoring CO₂ levels over time thus makes it possible to identify situations that require improved ventilation or a more in-depth analysis of indoor environments. This approach applies to hospitals, clinics, nursing homes, medical-social facilities, and doctors’ offices alike.

Is CO₂ sufficient for assessing indoor air quality?

Although CO₂ is an excellent indicator of airtightness, it alone is not sufficient to assess all issues related to indoor air quality.

The SF2H guidelines also note that CO₂ does not directly measure the concentration of infectious respiratory particles in the air.

In healthcare facilities, other pollutants may be present, including fine particulate matter, volatile organic compounds (VOCs), formaldehyde, biological agents, and chemicals generated by healthcare activities. Furthermore, two rooms that appear similar at first glance may have very different conditions depending on their use, the number of occupants, ventilation practices, and the actual performance of the ventilation system.

That is why many organizations today want to objectively assess their environments before taking corrective action or making technical investments.

Why conduct an indoor air quality assessment in a healthcare facility?

Installing an air purifier or modifying a ventilation system without first objectively assessing the existing conditions is precisely what the SF2H recommendations seek to avoid. R10 requires a formal risk analysis before any portable unit is installed. R7 recommends mapping actual ventilation under real-world occupancy conditions. This mapping must be performed under real-world occupancy conditions when CO₂ is used as an indicator, and updated whenever there is a significant change to the premises.

The starting point is therefore always the same: understanding what is actually happening on the ground before taking action.

An indoor air quality assessment makes it possible, in particular, to:

to analyze CO₂ levels over time and under actual occupancy conditions,
to identify areas under lockdown,
to measure certain pollutants in the air,
to gain an objective view of indoor environments,
to help prioritize corrective actions based on the level of risk to patients and residents.

This is the approach NatéoSanté : first, an on-site assessment to objectively evaluate the situation, followed by tailored solutions, including continuous monitoring of CO₂ levels and air quality over time and, if the analysis warrants it, the installation of HEPA H13-certified air purifiers.

This approach makes it possible to prioritize the most effective measures based on the actual level of risk: improving air circulation practices, optimizing ventilation, raising staff awareness, or implementing additional solutions. It also allows for monitoring their effectiveness over time—something no single piece of equipment can guarantee on its own.

I would like to have my indoor air quality tested

What role do air purifiers play in the SF2H guidelines?

The SF2H recommendations emphasize that priority should always be given to air exchange, mechanical ventilation, and the ventilation of indoor spaces. Portable air treatment units are used as a supplementary measure.

Recommendation R10 is clear: it is strongly recommended that a risk assessment be conducted before installing any mobile device, taking into account the room’s basic ventilation parameters, its intended use, other possible measures to improve ventilation, the supply of fresh air, and the patients or residents being cared for.

If this analysis concludes that a mobile unit is appropriate, Recommendation R11 specifies that it must use at least HEPA H13 filtration in accordance with standard NF EN 1822-1. The SF2H adds that it should be positioned so as not to draw airflow toward the entrance to the patient’s or resident’s room.

Finally, R9 reminds us that all ventilation systems must undergo annual preventive maintenance with documented records. This is an important reminder: equipment installed without ongoing monitoring does not guarantee controlled air quality. This is precisely why NatéoSanté its solutions on an operational lease basis—air quality monitoring sensors and air purifiers with HEPA filters—with integrated maintenance, so that compliance is not a one-time event but an ongoing reality.

Toward a more comprehensive approach to infection control

The SF2H recommendations from October 2024 outline a clear roadmap for the prevention of healthcare-associated infections: prioritizing ventilation, mapping non-compliance, conducting a risk analysis before taking any further action, and monitoring over time.

What these recommendations highlight is that no single solution—whether an air purifier or a change in ventilation—is sufficient without a detailed understanding of indoor environments. Air quality cannot be dictated; it must be measured, monitored, and adjusted.

This is exactly the approach NatéoSanté to healthcare and medical-social facilities: starting with an on-site assessment to identify actual conditions and prioritize the areas most at risk, then deploying tailored solutions, including continuous air quality monitoring and the operational rental of HEPA H13-certified air purifiers, all backed by long-term support.

Why is air quality important in preventing healthcare-associated infections?

Indoor air quality plays a critical role in preventing healthcare-associated infections (HAIs), as certain infectious agents can be transmitted through the respiratory tract in the form of aerosols. When ventilation is inadequate or air exchange is limited, these particles can accumulate in occupied spaces and increase the risk of exposure for patients, visitors, and healthcare workers.

What does SF2H recommend regarding air quality?

The SF2H 2024 recommendations emphasize the importance of ventilation, room air exchange, and indoor environmental control in preventing the respiratory transmission of infections in healthcare settings. They also stress the importance of measurement campaigns, particularly CO₂ monitoring under actual occupancy conditions, to identify high-risk areas and prioritize corrective actions.

Why is CO₂ monitored in healthcare facilities?

CO₂ is used as an indicator of indoor air quality. High levels may indicate insufficient air exchange and a greater accumulation of exhaled aerosols.

What CO₂ level does the SF2H recommend?

SF2H Recommendation R5 states that it is strongly recommended that fresh air supply rates be sufficient to maintain CO₂ levels below 1,300 ppm in occupied spaces, and if possible, below 800 ppm. This 800 ppm threshold is also set as the maximum occupancy level for rooms housing patients at high risk of infection.

Do the SF2H guidelines mention air purifiers?

Yes. Recommendation R10 requires a formal risk assessment prior to the installation of any mobile air-handling unit. If the assessment is favorable, Recommendation R11 specifies that the unit must be equipped with at least H13 HEPA filtration in accordance with standard NF EN 1822-1, and positioned so that the airflow is not directed toward the room’s entrance door.

Which portable air treatment units does SF2H refer to?

The recommendations specifically mention systems equipped with HEPA H13 filters or higher, in accordance with standard NF EN 1822-1, provided they are properly sized and maintained.

Do air purifiers replace ventilation?

No. Air purifiers are not a substitute for air exchange or proper ventilation. They can be used as a supplementary measure to help reduce certain airborne particles.

Can CO₂ be used to detect viruses in the air?

No. CO₂ does not directly measure infectious respiratory particles in the air. It serves as an indirect indicator of air exchange and the degree of enclosure in a space.

Why conduct an air quality assessment in a healthcare facility?

An indoor air quality assessment provides an objective assessment of indoor environments, analyzes CO₂ levels and certain pollutants, and identifies appropriate measures to improve air quality and reduce risks associated with confined spaces.

What is the ventilation mapping recommended by the SF2H?

SF2H Recommendation R7 calls for a mapping of actual ventilation to be established in all healthcare and medical-social facilities. It must be conducted under actual occupancy conditions, shared with management and infection control teams, and updated whenever there are significant changes to the premises. It serves to identify non-compliance issues and prioritize work based on the level of risk to patients.

Where should you start to comply with the SF2H recommendations on air quality?

The first step recommended by the SF2H is to determine the actual state of ventilation and CO₂ levels in your facilities under real-world occupancy conditions. This is the starting point for the mapping required by R7 and the risk analysis mandated by R10 prior to any deployment of additional equipment. NatéoSanté an air quality assessment specifically designed for healthcare and medical-social facilities to help you objectively assess your environments and prioritize your actions.