A security guard who had an unknown substance sprayed in his face during a robbery in Brighouse has escaped serious injury.
Police said the substance had yet to be identified but that the victim suffered only a “mild skin irritation.”
The man was kept in hospital overnight as a precaution.
It was feared he was the victim of an “acid attack” and he was taken to Calderdale Royal Hospital in Halifax for treatment.
Det Insp Gary Stephenson, of Calderdale CID, said: “Extensive enquiries into this incident are continuing. Whilst the victim did not sustain serious injuries, clearly the incident was incredibly distressing for him, and people who witnessed what took place.
“We have spoken to a number of witnesses already who were around the location when the incident took place, but would ask anyone who has not yet spoken to the police who has any information to come forward.
“I would seek to reassure the public that this appears to have been an isolated, targeted incident, however we always would encourage anyone with any concerns to speak to their local neighbourhood policing team.”
Anyone with information should contact Calderdale CID via 101 using the reference 13180037476.
Information can also be passed to Crimestoppers, anonymously and in confidence, on 0800 555 111.