I am working with a conductive appliance that a user will be in constant contact with over extended periods of time and the appliance is constantly earthed. These two facts cannot change, other than in a circumstance where the user may be in danger.
My question is whether or not it is safe for someone to be in constant contact with the earth line over extended periods of time.
I have heard some people saying that if there is a power fault or some sort of electrical issue (even a lightning strike) that this could in fact be dangerous, yet I have also heard that it is completely safe and that bathtubs are earthed and completely safe.
I recall that in the past I have felt some sort of low voltage tingle when directly contacting a ground pin which was possibly a result of an electrical fault somewhere in the house and this concerned me a bit for this application.
Is it possible to detect stray currents in the earth line and activate an earth circuit breaker at such an event? Is there a sort of safety feature to prevent unlucky circumstances occurring when in contact with earth? Also, would a setup like this break any health and safety regulations?