Gamma radiation for sterilization of textile based materials for personal protective equipment

In a pandemic context, personal protective equipment (PPE) as protective clothing is essential to ensure the safety of health professionals, caregivers and patients. Although most of the PPE is disposable, it can be effectively and safely reused once sterilized and washed, as long as they keep an adequate performance. The reuse of PPE also brings unquestionable benefits both in economic and environmental terms. This work aims to evaluate the possibility of using gamma irradiation to sterilize textile materials, with different compositions, intended to be used in the production of PPE. It was determined the number of cycles of sterilization followed by washing + drying that each material was able to withstand, while keeping adequate properties. Changes in morphology, colour, wettability, liquid permeability, and mechanical resistance of the materials were evaluated after different number of cycles and related with modifications in their chemical structure and eventual physical degradation. It was found that two materials, a Jersey knitted fabric 50% cotton/50% polyester and a Twill woven fabric 100% polyester, both coated with a 100% polyurethane membrane (samples A2 and A6, respectively) were able to withstand at least 20 cycles without suffering significant morphological or structural modifications. More, sterilization tests proved that even after that number of cycles, the materials can be efficiently sterilized by gamma irradiation. These results will allow more time to refill supply stocks, in case of an exceptional event such as a pandemic outbreak.