Freudenberg Sealing Technologies Hygienic Usit washer seals screw and bolt heads to protect aseptic isolators and areas that make contact with both the product and external influences from contamination. The washer's sealing bead is made of 70 EPDM 291 material, which is compliant with Food and Drug Administration's EC 1935/2004 requirements, and is biologically safe according to United States Pharmacopoeia Class VI criteria up to 121 C, according to the company. It is available in standard sizes: M5, M6, M8, N10, M12 and M16.