Several cannabis users have been taken ill after smoking a batch which has been contaminated with glass.
The cannabis has been contaminated by an industrial spray
Staffordshire Police issued a warning about the cannabis after several people in the Chase area were taken ill during the last week.
The cannabis, or grit-weed, looks normal but has tiny glass beads embedded into the leaves and can leave smokers with mouth ulcers and coughs.
Police are urging anyone with the grit-weed to destroy it.
Officers are concerned the cannabis is being produced on an industrial scale and that a glass frosting spray is being used.