Two men between the ages of 18 and 25 are believed to have sprayed the chemical inside the store Sunday night, reports news station KTRK in Houston.
Customers began coughing, sneezing and vomiting. More than 100 people were evacuated from the store, and five were hospitalized.
The store has since re-opened.
Authorities are using surveillance tapes to identify suspects, KTRK reported.