Non-polarized fixed capacitor. A non-polarized ("non polar") capacitor is a type of capacitor that has no implicit polarity -- it can be connected either way in a circuit. Ceramic, mica and some electrolytic capacitors are non-polarized. You'll also sometimes hear people call them "bipolar" capacitors.
Correspondingly, what does it mean when a capacitor is said to be polarized?
In a polarized capacitor the insulating material is a dielectric, meaning it becomes a dipole when the capacitor is charged. Ordinary capacitors do not have a positive and negative side, but polarized capacitors do have a positive side and a negative side.
Are capacitors toxic?
Whether it is toxic or not, you should treat it as though it is toxic! But there is no need to get paranoid about it. The capacitor people use a variety of electrolytes and some could be mildly toxic. All are corrosive because they contain things like boric acid and salycilic (sp) acid.