Is Silly String dangerous?

By: Valentina Caval
Wajeeha Jafferalli
• Silly String was invented by Leonard A. Fish and
Robert P. Cox
• A patent was issued in 1972
for foamable resinous composition
• Originally it was
• named as :“squibbly.”
• A resin forms the plastic structure of the strand. The original formula used
polyisobutyl methacrylate— an acrylic resin.
• A surfactant—or surface-active agent—helps the resin foam and modifies the
stickiness of the strands.
Propellant: 75% liquid in the can :
forces the other ingredients out of the aerosol can,
and causes them to foam and helps form the skin.
The propellant described in the patent is Freon-12.
• The Silly String manufactured today uses
other propellants –Freon-12 is an ozone
depleting substance that is no longer manufactured.
Dibutyl phthalate makes it sticky to the touch.
Silicone fluids such as dimethyl siloxane make the finished
streamers easier to peel away from most targets.
A bit of solvent such as dichloromethane keeps everything
as a one-phase mixture.
dimethyl siloxane
Chemical Structures
Dibutyl phthalate
At normal air pressure the propellant
in Silly String would be a gas. The
high pressure inside the can keeps it
in its liquid state.
When you press the nozzle, a valve
opens inside the can, giving the
highly compressed liquid a chance to
escape. Liquid rapidly moves up the
tube inside the can, and travels from
the high-pressure environment inside
to the lower-pressure environment
Outside of the can, the liquid
propellant becomes a gas, causing
the remaining ingredients to foam.
• It was used by American and British
forces to detect tripwires for
explosive booby traps.
• The soldier would stand in the
doorway and spray the material
over the suspect area. If the
string fell to the ground there
were no tripwires. However, if
there was a tripwire, the string
would be suspended in the air
without pulling the wire
• They can not use silly string in the
current war because you cant ship
aerosol over seas
• Family Games
• Parties:
welcome home
• Child activities
• Its large proportion of propellant can also
give Silly String two seemingly opposite
safety hazards:
• Some propellants are flammable, and others
become so cold when leaving the container
that they can freeze a person's skin.
• Silly string can clog storm drains and take up space
in landfills.
• Silly String is banned in Hollywood on Halloween
night : If you are
caught with
silly string you could
be faced with a
$1,000 fine!

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