Nonwovens and felts from synthetic fibers (polyester, polypropylene) or from glass fibers are the mostly used filter media in air filtration. These mterials offer high efficiency, long service life and a good price-performance ratio. However the modern growing trend to replacem petroleum-based fibers with bio-based and bio-degradable polymers dictates a new challenge for researchers, filter developers and manufatures. The research aims presented here at exploring PLA fibers as an alternative material for applications in air filtration. Particular focus is made on the characterisation of the mechanical properties of PLA under aging conditions, which are relevant for the applications as filter media. On the testing the filtration characteristics of the PLA nonwovens depend on the textile parameters as well as on the quantification of the biodegrabiity of the PLA-based materials...