In March 2011, China's Ministry of Agriculture said the government would launch a one-year crackdown on illegal additives in pig feed, after a subsidiary of Shuanghui Group , China's largest meat producer, was exposed for using clenbuterol-contaminated pork in its meat products. A total of 72 people in central Henan Province, where Shuanghui is based, were taken into police custody for allegedly producing, selling or using clenbuterol.  The situation has dramatically improved in China since September 2011, when a ban of clenbuterol was announced by China’s Ministry of Agriculture. 
Pediatric Subjects Aged 4 to 11 Years: The efficacy of Ventolin HFA was evaluated in one 2-week, randomized, double-blind, placebo-controlled trial in 135 pediatric subjects aged 4 to 11 years with mild to moderate asthma. In this trial, subjects received Ventolin HFA, CFC 11/12-propelled albuterol, or HFA-134a placebo. Serial pulmonary function measurements demonstrated that 2 inhalations of Ventolin HFA produced significantly greater improvement in pulmonary function than placebo and that there were no significant differences between the groups treated with Ventolin HFA and CFC 11/12-propelled albuterol. In the responder population treated with Ventolin HFA, the mean time to onset of a 15% increase in peak expiratory flow rate (PEFR) over the pretreatment value was minutes, and the mean time to peak effect was approximately 90 minutes. The mean duration of effect as measured by a 15% increase in PEFR over the pretreatment value was greater than 3 hours. In some subjects, duration of effect was as long as 6 hours.