Halt or limiting production for Yellow Warning
New version of Beijing Emergency Plan for Severe Air Pollution shall be released with duration of pollution being calculated by "hour". Upon yellow warning, enterprises shall halt or limit production. Upon blue warning, outdoor operations for spraying, paining, or whitewashing for slope protection shall be stopped. Criterions on halt or limiting production for manufacturing enterprises have been changed to Yellow Warning from Orange Warning. Besides, the concept of "hour" has been introduced in starting conditions, for example, heavy pollution for one day or 24 hours shall be subject to Blue Warning.