Thomas Charnley hurled liquid from a jar at a man in a supermarket in Viewpark, North Lanarkshire in April this year.
His victim, who he claimed had threatened him and his partner, suffered blisters to his skin as the toxic liquid began to burn.
The 44-year-old fled after the attack which was captured on CCTV.
At the High Court in Glasgow today Charnley admitted assaulting the man to his severe injury.
Jailing him, judge Lord Burns told Charnley: “This was a bad attack on a man in a public place with acid. It is fortunate he was not more seriously injured.
“I consider you pose a serious risk of harm to the public.”
Lord Burns ordered Charnley to be monitored in the community for three years after his release from prison.
Charnley waved to family and friends as he was led away to the cells.
Prosecutors believe the substance used in the horrific attack was sulphuric acid or a similar liquid.
The court heard he threw the acid over the victim as they both shopped in the Scotmid Store in Viewpark.
He received hospital treatment, but did not suffer permanent scarring.
Ronnie Renucci QC, defending, said: “He cannot recall putting the jar in his pocket. He left the house and was going to buy beer.
“This is not a case where he left looking for trouble.”
Charnley was jailed in 1997 after he beat a man to death in Coatbridge.