1. Male and female subjects aged 18 through 45 years in good general health other than asthma that is consistent with the definition of mild (intermittent or persistent) asthma by the 2002 Expert Panel report of the NAEPP: Night time symptoms no more than once weekly and day time symptoms <1 per day; lung function, FEV1 or PEF ≥ 80% of predicted value and PEF variability ≤ 30%. Note: the Principal Investigator must determine that the subject's asthma is consistent with this definition e.g., it is not required for the Investigator to obtain historical PEF values to calculate variability.