An extensive subjective test has been carried out to establish static control needs by carpet end use. Results from the test have been analyzed to establish a stochastic relationship between chance of objectionable shock and carpet-static test rating. The relationship, first established under laboratory conditions, was modified to include the effects of key environmental factors such as relative humidity, soiling, and traffic patterns. The effect of each factor on the basic relationship was analyzed separately. The cumulative results show that Antron®III carpets rated ≤3.5 kV by AATCC static propensity test offer shock-free performance in commercial applications. Similar performance in residential areas is achieved with carpets rated ≤4.5 kV.