Anne Marie Simpson, 35, produced a bottle and told her female victim, “I’ll use this ammonia. It will burn your eyes, you’ll not be able to see”, a court heard.
Simpson, of Hazlitt Avenue, Biddick Hall, then threw the bottle after leaving Tesco Express in Whiteleas Way, Whiteleas, hitting the employee on an arm and leg.
The attack at 10.40pm on Wednesday, May 11, caused temporary skin reddening, though any substance present was not ammonia.
Drug user Simpson could remember nothing of her crime and refused to answer police questions, but admitted her guilt at South Tyneside Magistrates’ Court.
District Judge Paul Currer jailed her for a total of 24 weeks after also activating an existing 16-week suspended sentence imposed in April.
Prosecutor Clare Irving said: “The defendant is seen in the store. She comes in carrying a Sports Direct bag for life.
“Because of this, she was watched by staff who tried to prevent her from walking around.
“She was putting meat products from a fridge into her basket and then into the Sports Direct bag.
“After 7pm, the doors are on an automatic lock which means customers have to be let out.
“Near the door, the defendant produced a bottle and said, ‘I’ll use this ammonia. It will burn your eyes, you’ll not be able to see’.
“The police were called. She was let out of the store and threw the bottle towards the employee, hitting her left arm and left thigh.”
The court heard Simpson was quizzed at Sunderland’s Southwick police station but refused to answer questions.
Elizabeth Dunbar, defending, said Simpson was under no illusions her suspended sentence would be activated and she would be jailed.
She added: “She knows that the only place she is going today is Low Newton. She commits these offences soon after the suspended sentence.
“This is a young lady who had problems with drugs, she still has problems with drugs.
“In relation to the assault, it seems horrible but what she says to me is that she has no recollection of saying those words.
“She threw something, but it certainly wasn’t ammonia. It’s full credit for an early guilty plea.”
Simpson pleaded guilty to assault and theft from a shop, with the value of the items taken being unknown.
She was handed the suspended sentence in April at the same court on admitted charges of shop theft.
Judge Currer described the new offences as “unpleasant” and jailed Simpson for eight weeks for each, to run concurrently.
The suspended sentence will run consecutively, giving a total sentence of 24 weeks. Simpson must also pay a £128 victim surcharge.