A number of Fire appliances along with a DIM unit and officers could be seen arriving at the Queen Elizabeth hospital that is being used as a holding area whilst tests are carried out on the substance.
A spokesman for the Met Police said at 1.37pm on Sunday, 8 November, police were called to an address in Shooters Hill Road, SE10, to reports of a suspicious package.
Officers attended, along with London Fire Brigade and London Ambulance Service.
The package was assessed as non-toxic and non-hazardous. The premises has now re-opened and the crime scene is closed.
This incident is not being treated as terror-related.