Are TruDesign Skin Fittings certified ?

YES
The TruDesign Skin Fittings (Thru Hulls) are compliant to

ISO 9093-2 and certified by the International Marine Certification Institute (IMCI) and Bureau Veriitas.
ABYC H-27. (American Boat and Yacht Council) - Seacocks, Thru-Hulls Fittings and Drain Plugs..