Razor gangs were criminal gangs that dominated the Sydney

Sydney

Sydney is the most populous city in Australia and the state capital of New South Wales. Sydney is located on Australia's south-east coast of the Tasman Sea. As of June 2010, the greater metropolitan area had an approximate population of 4.6 million people...

 crime scene in the 1920s. With the passage of the Pistol Licensing Act (NSW) 1927, the New South Wales State Parliament imposed severe penalties for carrying concealed firearms and handguns. Sydney gangland figures then chose razors as preferred weapons, for their capacity to inflict disfiguring scars.
The upsurge in organised crime was caused by the prohibition of sale of cocaine by chemists (under the Dangerous Drugs (Amendment) Act 1927), the prohibition of street prostitution (under the Vagrancy Act NSW 1905), the criminalisation of off-course race track betting (under the Betting and Gaming Act 1906) and the introduction of six o'clock closing

Six o'clock swill

The six o'clock swill was an Australian and New Zealand slang term for the last-minute rush to buy drinks at a hotel bar before it closed. During a significant part of the 20th century, most Australian and New Zealand hotels shut their public bars at 6 p.m. A culture developed of heavy drinking...

 for public bars after passage of the Licensing Act 1927 (NSW)
By the early 1920s, almost sixty years had passed since German chemists Friedrich Gaedcke

Friedrich Gaedcke

Friedrich Georg Carl Gaedcke was a German chemist. He was the first person to isolate the cocaine alkaloid which happened in 1855....

 and Friedrich Wohler

Friedrich Wöhler

Friedrich Wöhler was a German chemist, best known for his synthesis of urea, but also the first to isolate several chemical elements.-Biography:He was born in Eschersheim, which belonged to aau...

 and Wohler's doctoral chemistry student Albert Niemann

Albert Niemann (chemist)

Albert Friedrich Emil Niemann was a German chemist. In 1859 - about the same time as Paolo Mantegazza - he isolated cocaine, and he published his finding in 1860.-Life:...

 had isolated the first pure cocaine in 1855 and 1859, and since Italian doctor Paolo Mantegazza

Paolo Mantegazza

Paolo Mantegazza was a prominent Italian neurologist, physiologist and anthropologist, noted for his experimental investigation of coca leaves into its effects on the human psyche. He was also an author of fiction.-Life:...

 had discovered its euphoriant and stimulant effects as a recreational drug.

Initially, cocaine was incorporated into consumer products and beverages, until concern grew about its addictive properties.