The Pueblo City-County Health Department says no specific cause has been identified for the health reactions experienced by the workers at Integrated Document Solutions on Friday.
16 people became ill after they were exposed to an unknown substance. The health department says the reactions by victims were not considered serious.
Earlier, investigators found three different chemicals that could have caused a reaction, including pesticides, burnt jet fuel exhaust, and fertilizer.
The health department say as a precautionary approach for the safety of the workers, cleaning of the inside of the building will begin and the air exchange system of the building will be tested to ensure it meets national standards.
PCSO told 11 News that initially, nine employees of Integrated Document Solutions showed symptoms at work and went to the emergency room at Parkview Medical Center in Pueblo West. Seven non-employees were "indirectly exposed," and showed symptoms.