After finding it nearly impossible to get a job he decided to forge his own future. Now, over 20 years since he kicked his drug-habit, the Singaporean is the successful owner of a chain of restaurants called Eighteen Chefs.
While the restaurants focus on providing quality food, from the beginning Teo was determined that his business venture would also concentrate on helping those marginalized by society.
"I realized that in society there is this gap. Where once you have a criminal record you are unable to live a normal life, you are unable to integrate back to society," he says.
"We are able to provide training and give them their self-respect which they lost many, many years ago."
Before setting up Eighteen Chefs, Teo trained at Fifteen, Jamie Oliver's London restaurant. He then went on to run a 200-seater Chinese restaurant, with 80% of the staff having a criminal record.
However, Teo found that the high number of ex-offenders was too difficult to manage. His first Eighteen Chefs establishment started off with a smaller proportion, 35% in 2012, and now 50% of his employees are troubled young people and people with criminal records.
There have been a number of success stories among staff, one of Teo's employees began as a server and is now a regional manager at an international restaurant earning more than $6,000 a month.
Teo does not even mind if his employees steal recipes and ideas from him to start up their own small businesses, he's just happy they aren't going back to their old ways.
While his new life is free of his old habits and addictions, his restaurants retain an allusion to his former ways: the number 18 refers to a well-known Singaporean street gang.
But rather than advocate his breaking bad past, he would rather young people tempted by a thug life would pick up a pan and chopping knife rather than a switchblade.