POLYURETHANE-51 is graded A (Safe) by Expert·ING, based on COSING regulatory data.
POLYURETHANE-51
Safety grade: A
Polyurethane-51 is a synthetic film-forming polymer that creates a protective coating on nail surfaces. It helps nails stay strong and flexible by forming a breathable shield.
This ingredient conditions and protects nails by forming a flexible, adhesive film that strengthens nails, reduces brittleness, and helps prevent chipping and breaking.
Graded using: COSING.
Last verified: May 26, 2026
Other Nail Conditioning ingredients
- COMMIPHORA MYRRHA RESIN EXTRACT — Grade A
- ECHINACEA ANGUSTIFOLIA ROOT EXTRACT — Grade A
- VACCINIUM MYRTILLUS LEAF EXTRACT — Grade A
- 2-METHYLPROPANAL — Grade A**
- 4,4'-ISOPROPYLIDENEDIPHENYL/EPICHLOROHYDRIN COPOLYMER DIACRYLATE — Grade A
- ACETALDEHYDE — Grade F**
- ACRYLIC ACID — Grade A**
- AMP-ISOSTEAROYL HYDROLYZED SILK — Grade B