Important Safety Information | NIOX VERO® User Manual (PDF)

For US Healthcare Professionals Only


Safety of FeNO by NIOX® in the COVID-19 pandemic

Since the onset of the COVID-19 pandemic, there have been concerns about performing objective tests for asthma diagnosis and management due to potential contamination with aerosols generated during the testing procedures.

FeNO by NIOX® is not an AGP

A study published in November 2021 looked at the risk of aerosol generation from common test procedures (spirometry, peak flow and FeNO). During testing with NIOX VERO®, the investigators found that “FeNO measurement produced negligible aerosols” and that they “could not elicit any aerosol emission from the FeNO device”. They concluded that FeNO testing “does not generate significant aerosol concentrations compared with coughs in healthy volunteers and patients with lung disease”, supporting the removal or omission of FeNO from lists of aerosol-generating procedures (AGPs).1

Another 2021 paper, which also excludes FeNO from the list of tests to avoid during the COVID-19 outbreak, said: “FeNO measurements do not cause significant risk of aerosolization and may be permissible. FeNO may be used when available as the risk of transmission is lower.”2 The authors cited an editorial that notes FeNO “does not require forced manoeuvres and reduces the potential for coughing and droplet formation, [and] could represent a possible first functional approach to diagnosis and assessment of patients with asthma.”3

A December 2020 review examining potential alternatives to pulmonary function testing during the pandemic stated: “Institutions familiar with FeNO testing may therefore consider using this technology as a potentially safer, ie less likely to generate aerosols, method in inpatient and outpatient settings for diagnosing and following patients with asthma characterised by Type 2 airway inflammation”.4

In addition, there have been no spontaneous reports of cough using NIOX VERO® and no coughing-related adverse events during NIOX VERO® clinical trials.

NIOX® patient filters are exceptionally effective

Using a NIOX VERO® is safe, easy and non-invasive. Every volunteer or patient taking a FeNO test with a NIOX VERO® receives a mouth filter in a sealed package that is unwrapped and attached to the device’s breathing handle. The single-use mouthpiece filter must be changed for each new patient but may be used on multiple occasions in the same session (by the same patient).

The patient completely closes their lips around the mouth filter before inhaling and exhaling steadily through the breathing handle.

NIOX VERO® mouth filters meet international standards of filtration performance for “Breathing System Filters for Anaesthetic and Respiratory Use” (ISO 23328-1, EN 13328-1), to which many other respiratory devices in hospital settings also adhere. The filters have been tested for bacterial filtration efficiency (BFE) and viral filtration efficiency (VFE) to the highest ASTM standard F2101.

Cleaning and disinfecting NIOX® products is easy

NIOX VERO® should be regularly cleaned and decontaminated, as with all surfaces in a patient-care setting.

Alcohol (such as ethanol and isopropyl alcohol) and alcohol-containing disinfectants must not be used for cleaning the NIOX VERO® device or breathing handle, as this will affect both the performance and results.

Patients and physicians may disinfect their hands with alcohol-based hand sanitisers and make sure their hands are completely dry before touching the NIOX® device or accessories, such as the breathing handle.

However, several products are compatible with NIOX® devices, including:

  • Sodium hypochlorite or household bleach (<0.65%),
  • Quaternary ammonium compounds (<5%),
  • Biguanides (<1%),
  • Isothiazolinones (<0.01%).

For COVID-19 specifically, sodium hypochlorite 0.5-0.65% and benzalkonium chloride 0.05-0.2% are effective against SARS-CoV-2 (the coronavirus causing COVID-19) and can be used to clean NIOX® products.

Access our comprehensive list of chemicals and wipes that can be used to effectively clean NIOX® products.


Learn more about the gold standard FeNO testing device.

Get started with NIOX VERO®

Join the thousands of healthcare professionals who have already performed over 50 million FeNO tests with NIOX®, and improve patient outcomes.

Click to learn more today


1. Sheikh S et al. Are aerosols generated during lung function testing in patients and healthy volunteers? Results from the AERATOR study. Thorax Published Online First: 02 November 2021. doi: 10.1136/thoraxjnl-2021-217671. 2. Christopher DJ et al. Pulmonary function testing during the COVID-19 pandemic. Lung India. 2021;38 (Suppl 1):S91-6. 3. Lombardi C et al. Rethinking respiratory function laboratories in the era of coronavirus disease 2019, Considerations for today and the day after. Ann Allergy Asthma Immunol. 2020;125(2):210-1. 4. Kouri A, et al. Addressing reduced laboratory-based pulmonary function testing during a pandemic. Chest. 2020; 158(6): 2502-10. 5. Data on file C-NIOX-0009. ­© Circassia Group PLC.