Police are seeking a "hugely irresponsible" man who yelled "I've got acid" before squirting what is believed to be cleaning fluid at drinkers outside a West Midlands pub.
Officers have released CCTV images of the man they wish to speak to who is suspected to have sprayed liquid from a bottle at a group of people outside The Chalice pub in Dickens Heath, Solihull.
The substance hit one man in the face, which prompted him to quickly wash it off with water from a nearby dog bowl. The man was not hurt during the incident as he was wearing glasses and the liquid was believed to be cleaning fluid.
The suspect was then driven away by an accomplice in a car.
The incident occurred following a series of acid attacks in the UK, including five people who were hit in the face by a corrosive substance across north and east London in less than 90 minutes.
PC Dave Spencer, from Solihull Police's Investigation Team, urged anyone who recognises the man to get in touch.
He said: "Given the recent spate of acid attacks in London this was a hugely irresponsible act and very scary for the victim. The attacker shouted 'I've got acid' but we believe it was actually an ammonia-based cleaning fluid.
"The victim was wearing glasses, which prevented the substance going into his eyes and he reacted quickly by picking up a dog bowl of water and throwing it over his face. He didn't report feeling any burning sensation and was thankfully unhurt.
"It's understood the attacker was in a car being driven anti-socially in Main Street and, when the group shouted for them to slow down, the pair jumped out and confronted them.
"We need to know who this man is and I'd urge anyone with information to contact me on the 101 number or call Crimestoppers anonymously."
The man in the CCTV is described as wearing a blue T-shirt, beige shorts, shoes and with a 'man bag' across his shoulder; he has dark hair, a closely cropped beard and is believed to be in his 20s.
West Midlands Police have already arrested a man suspected of driving the car, seized a vehicle and recovered a bottle containing a clear liquid.
A 21-year-old man from Solihull has been charged with a public order offence and is due to appear at Birmingham Magistrates Court on 16 August.