The breathing resistance test measures how easily air can pass through a mask when you inhale, which is an important factor for comfort and effective respiratory protection. During the test, the mask is placed on a calibrated testing machine and exposed to a controlled airflow of 85 L/min. The machine then measures the pressure drop across the mask material. A lower pressure drop means the mask is easier to breathe through, while a higher value means more effort is required.
The Cambridge Mask sample recorded an inhalation pressure drop of 193.77 Pa at 85 L/min. This is well within the GB 2626-2019 limit for KN95/KN100 masks (≤350 Pa) and also aligns with other global standards. For reference, NIOSH allows up to 343 Pa, while EN 149 requirements for FFP2/FFP3 respirators (tested at a higher airflow of 95 L/min) typically fall between 240–300 Pa.
Overall, even 5 years after production, the mask still maintains good airflow permeability and balanced breathing resistance. This indicates that the expired mask can still offer effective filtration performance without compromising user comfort during normal use.
If you have further question, please contact us by email at info@cambridgemask.com or Chat button on our sites to connect with our Customer Service Team.