MOUNTAIN VIEW—According to the Mountain View Fire Department, three Starbucks employees reportedly got sick after inhaling toxic fumes in one of the coffeehouse’s bathrooms on Tuesday, December 13.

The MVFD was alerted at approximately 12:40 a.m after the employees began feeling “sick” and “short of breath” as they were cleaning the restroom. When officials arrived, two of the three employees were transported to a local hospital for treatment.

Lynn Brown, representative for the MVFD informed the Mountain View Voice that the fumes were caused by an “accidental combination of chlorine and ammonia.”

Chlorine from the bleach used to clean the restroom had mixed with ammonia from human waste as one of the toilets backed up, Brown said. It caused hazardous fumes to formulate, which can be life threatening if “enough builds up in a confined area.”

A gas monitor detected heightened levels of ammonia present in the restroom. Officials opened up all doors and windows to ventilate the coffeehouse, and requested that the manager open the shop early to assure that no traces of the fumes remained on site. The scene was cleared by officials at around 1:38 a.m.