Silly String

Silly String is a colored, string-like substance that is shot from an aerosol can. It dries almost instantly, but can still be tacky and have a gooey texture. It is used at parties, parades and other festive occasions.

Though Silly String has been a popular party novelty since the 1970s, it may not be innocuous. First, when large amounts of it are sprayed at parades, it can interfere with urban infrastructure, especially by clogging up storm drains. Moreover, off-brand silly string often contains the Chlorofluorocarbon (CFC) compound Freon-12. This material can be very cold, even dangerously so, when it evaporates, and has been identified as a long-term environmental hazard due to its ozone-depleting properties. (Note: the Crazy String brand does not contain CFCs.) Also, Silly String should be used away from open flames—it can be somewhat flammable as it's being sprayed from the bottle.