Electrostatic discharge on ungrounded components
The damaging happens when you touch the component. Just at that moment a spark can hit between your hand and component's leg. If that hasn't still happened and the component is inside your hand it's in safe. The next dangerous moment is when you let the component touch something. For ex. you keep it between your fingers and one of the legs touches something that you do not touch. 

If it happens that you haven't an ESD safe workplace nor an ESD safe package and you must handle a component there, have at least a metallic platform for the component. Touch the platform at first when you take the component from it and touch it also before you leave the component on the platform. It's not fully safe because it's far too easy to have one second time gap between the touches. That's enough for you to generate a new potential difference for ex. by moving your feet on a plastic floor.

Components are often in ESD.safe bags which are said to be conductive. That can be true for the interior of the bags, but the outer surfaces can be of normal plastic. Thus placing a component in an ESD safe bag is effective if the component is placed inside and you touch the interior when you place or take a component.

BTW all semiconductor parts and circuit boards can be damaged by ESD. A  component can stil work after ESD hits but it's operation can be less reliable. It's operating voltage range and temperature range can be reduced substantially. Handling a computer circuit board with poor ESD protection is a waterproof way to get a computer which either does not work at all or it suddenly stops and must be reset.