Study on the Sanitization Efficacy for Safe Use of 3D-Printed Parts for Food and Medical Applications

Sanitization efficacy for safe use of 3D-printed parts for food and medical applications has been established in a 4-month lab study and controlled tests. The present study examined the continued use of sanitation techniques across 3 more months of testing and experimentation. Multiple specimens of the most common thermoplastics for Fused Filament Fabrication (FFF), were printed with a range of settings to test for bacterial/biofilm, masking (hiding) in the layer lines, gaps, and other imperfections of said prints. This study investigates methods of sanitation and cleaning to reduce or eliminate pathogens along with its biofilms from the defects and interstitial spaces that naturally occur in FFF printing. Results from various testing methods used in labs, indicate that 3Dprinted parts of PLA/PLA + (Polylactic Acid), and PETG (Polyethylene terephthalate glycol) can be cleaned to safe levels using warm water (120 °F), and non-concentrated dish soap. Examination and verification of cleanliness were completed via Petri dish preparations, and protein residue testing. It was found that Colony Forming Units (CFU) and Plaque Forming Units (PFU) had been reduced by 90%. Experimental results indicate that baking soda, when used with soapy water, may eliminate biofilms by chemical and physical action. It was also found that a 2-minute room temperature bleach water soak (200ppm), after a wash and rinse with soapy water, dissolved biofilms and pathogens to safe levels when tested by surgical technicians. It is noted to the reader that sanitation in this context refers to the method of bringing a surface or object to safe levels of cleanliness for food or medical preparation and storage.