The magical Magna-Tiles® Glow in the Dark 24-Piece Set is completely safe to play with. Each magnetic shape is composed of a food-grade ABS plastic, and there are zero BPAs, phthalates, latex, or other toxic materials. Meanwhile, sonic welding keeps the high-quality ceramic magnets securely contained in the tile. With their durable construction, scratch- and dent-free finish, and safe materials, Magna-Tiles® stay looking great after years of play – both indoors and outdoors. Magna-Tiles® aren’t just fun and safe – all sets are mutually compatible! The Magna-Tiles® Glow in the Dark 24-Piece Set can be combined and used with other sets for even more fun. Remember, though, the longer you expose these tiles to the light, the longer and brighter they will glow in the dark!