The requirements for medical face masks, such as filtration efficiency, breathability and biocompatibility, and the corresponding test methods are defined by legal test guidelines. The official standard for evaluating medical devices (DIN EN 10993) addresses biological effects, such as toxicity, irritation and allergy, resulting only from the medical device/material coming into contact with the skin or bodily fluids. Breathing through masks can trigger adverse respiratory toxicological effects caused by airborne substances that are released from the masks and then enter the lungs – even at very low concentration levels in the inhaled air. This can lead to long-term irritation or inflammation of the airways and even to allergies or asthma. A standard for evaluating airborne exposure in terms of respiratory toxicology does not exist.
Culture and exposure system for investigating airborne substances
Based on a culture and exposure system for airborne test substances patented by Fraunhofer ITEM, a unique in-vitro test battery to investigate the biological respiratory effects of face masks has been developed. The P.R.I.T.® ExpoCube® facilitates the exposure of cells at the air-liquid interface (air-liquid interface (ALI) cultures). This enables relevant endpoints of respiratory toxicological mechanisms to be investigated.