Police, fire and rescue and the ambulance service were called to a block of flats in the city's Easter Road shortly before 11pm on Saturday.
There were reports of a cyanide leak, but a spokesman for the Scottish Fire and Rescue service said: "There was no cyanide identified."
Samples have been taken from the scene and are currently being tested.
A man was taken by ambulance to the Edinburgh Royal Infirmary, but the Scottish Ambulance Service was unable to give any details about his condition.
A Scottish Fire and Rescue spokesman said: "We received a report from the ambulance at 10.48pm. It was a suspected chemical incident.
"It was reported from one of the flats in Easter Road that there had been a leak of cyanide powder.
"A male was taken to hospital by ambulance.
"There was no cyanide identified. The Fire Service has taken samples and they are being tested."
The incident follows the cyanide suicide pact of a Russian couple in the luxury Scotsman Hotel in central Edinburgh in August of this year.
The bodies of 27-year-old Igor Pavlov and Daria Kuchuk, 35, were found by staff in a sixth-floor bedroom, sparking a major incident in the city centre, with part of a main route locked down as the Scottish Government's emergency resilience team oversaw the operation.
About 25 specialist firefighters were sent to the scene and guests staying at the five-star hotel were evacuated during the investigation.