Householders in Bradford are being asked not to put hazardous waste such as used hypodermic needles into their recycling or general waste bin.
Bradford Council says even when sharp objects are enclosed in other containers, they burst out during the compacting process and cause a risk of serious harm to recycling sorting staff.
The authority added that all hazardous clinical waste such as needles should be returned to the chemist or other health facility from where they came.
Coun Sarah Ferriby, Bradford Council’s Executive Member for Healthy People and Place said: “We really don’t want needles in our recycling bins.
“They should be disposed of in the proper containers and returned to where they come from so they can be destroyed without causing risk to anyone.
“Recycling collection and sorting staff have a very challenging job to do without having to put up with serious risks to their health from items which should not be in the recycling stream.”