Hundreds of people were caught up in the evacuation of Brean Sands' Pontins holiday park because of a suspected chlorine gas leak.
Holidaymakers were forced to leave their rooms and wait outside as the Somerset resort was shut.
Fire crews, including a special environmental unit, were called after a possible leak yesterday evening (Tuesday 27 August).
Two people were treated with oxygen before fire fighters found no abnormal gas readings and discovered no leaking chemicals. Holidaymakers were allowed back in about an hour later.
Devon and Somerset Fire and Rescue service said:
A full evacuation of the site took place and 2 casualties were treated with Oxygen therapy after it was suspected they may have been exposed to gases. Two fire fighters in breathing apparatus gained access in to the plant room to take gas readings. No abnormal readings were detected and no leaking chemicals found. The incident was handed back to the police and the staff of the holiday park.