While some can withstand tens of thousand of volts before damage, some can be damaged by less than 200 volts. To avoid this, it is important that proper precautions and handling procedures be understood and followed.
People tend to believe their senses.
If they don't see or feel it, they assume nothing happened. While they may not feel the event, the circuit did. All IC manufacturers and users should be aware of the adverse results ESD can have on product reliability, along with the impact on product quality and cost. To help with this awareness, National Semiconductor prints ESD caution and warning symbols on the protective packaging containing its products. These industry standard ESD symbols are printed on the packing material to notify distributors and users that ESD precautions and proper handling procedures must be utilized to insure the reliability and quality of both the IC's inside as well as the electronic end products that will utilize them.