On December 1, 2013, the new United States Pharmacopeial Convention (USP) labeling standards for ferrules and cap overseals were adopted. Unless a notation is explicitly required for safe use on the vial cap ( eg: dilute before using ), words cannot appear embossed in a vial seal. Words such as “FLIP OFF” cannot be present in the plastic cap of a flip off seal under these new USP standards. The top of a “flip off / flip cap” style seal must be blank (no logos, no words, etc). To maintain compliance with this new standard, your facility should be using either our West Pharmaceuticals brand Matte flip off style seals or our 13mm West Smooth Gloss flip cap vial seals. The West Pharma Matte flip cap seals have a textured matte finish, while the West Smooth Gloss seals have a smooth glossy finish. Both of these flip cap style seals have no words or logos embossed in the plastic, and are available in numerous colors. Send us an email to see what colors are available. CLICK HERE TO ORDER WEST MATTE FLIP OFF SEALS