The incident occurred in north Belfast.
A thief barged into a premises on Oldpark Road in north Belfast on Saturday at 7.15pm.
A man - described as being around 30 years old, approximately 5’10” tall, of medium build, with dirty fair hair and a Southern Irish accent - entered a shop and threatened a female worker with a bottle of liquid he said was acid.
The worker in the shop managed to raise the alarm and the thief made away.
The PSNI are appealing for anyone who witnessed the incident or anyone with any information to contact Detectives in Musgrave Police Station on 101, quoting reference 978 05/01/19.
Alternatively information can be given to independent charity Crimestoppers anonymously on 0800 555 111.