Hasbro is trying to trademark the smell of Play-Doh in the US
It describes Play-Doh’s particular smell as “a unique scent formed through the combination of a sweet, slightly musky, vanilla-like fragrance, with slight overtones of cherry, and the natural smell of a salted, wheat-based dough”
It is rare for smells to be successfully trademarked in the US, it is not unheard of as long as it is capable of functioning as a trade mark. Most smells do not meet this ground but Hasbro arguably have a unique smell that has been known to children for generations. A container of Play-Doh was sent to the USPTO as part of the application process.
Hasbro has previously partnered with other companies to develop products that use the Play-Doh scent. In 2008 it worked with Demeter Fragrance Library, which makes and sells fragrances inspired by familiar everyday scents, to create an ‘eau de Play-Doh’ perfume to mark the putty’s 50th anniversary.