Polystyrene foam and Acetic Acid
Does Lemon Juice release any harmful chemicals from
polystyrene foam cups? It obviously does something to the polystyrene foam.
You are very correct in your observation that lemon, especially fresh
lemon, obviously does something to polystyrene. For those of you who wish to
observe this: Prepare a cup of hot tea in a polystyrene foam cup and squeeze a
lemon into it -- both juice and rind. The polystyrene at the surface of the
hot cup of tea quickly begins to "melt", in much the same way that can be
observed by putting a drop of acetone on a piece of polystyrene foam.
In the case of hot tea and lemon, is the lemon OILS in the skin that are
squeezed and leached out of the lemon rind that dissolve the polystyrene foam cup.
The "experiment" can be confirmed by putting a few drops of lemon oil
furniture finish on a piece of polystyrene foam.
Polystyrene foam used in food contact applications, cups, packaging,etc.,
contains few impurities. It has to in order to pass FDA regulations, and the
polystyrene foam itself is very high in molecular weight, so it is probably not
toxic. But from experience I can attest that it can cause quite a mess if
you like a lot of lemon in your tea and you walk away while the tea to cools
Click here to return to the Chemistry Archives
Update: June 2012