Hasbro has successfully trademarked the smell of Play-Doh. It says there’s no plans to use the trademark for legal action.
The trademark is in the sensory mark category, which is far less widely used than visual marks such as logos. That’s partly because applicants have to describe the flavor, scent or texture in a way that’s specific enough to be protectable but not so detailed that it could make it easier to reproduce for people who ignore the trademark.
Another drawback is that because it’s a trademark, whatever’s being protected can’t be a functional part of the product. That’s why attempts to trademark distinctive flavors of drinks have usually failed and why it’s difficult to trademark a cologne or perfume’s scent (which is the core purpose of the product.)
The Play-Doh trademark covers a “sweet, slightly musky, vanilla fragrance, with slight overtones of cherry, combined with the smell of a salted, wheat-based dough.” It’s now one of only a dozen or so trademarked scents, with MentalFloss noting that others including strawberry scented toothbrush, some engine lubricants which are made to smell pleasant, a pina colada smell used on ukuleles, and a couple of scents used for atmosphere in retail stores.
Hasbro told Gizmodo that it has no current plans to use the trademark but that it allows for “a whole host of fun and creative opportunities in the future.” That could mean using the scent in other products as the trademark covers several broad product categories beyond just toys, though it likely wouldn’t protect a specific Play-Doh cologne.