A hazmat team responded to the area of Pueblo and Tenth avenues, southwest of Corcoran, at about 9:30 a.m.
They learned that the group had been working in a field that had been sprayed with a fungicide the night before.
It was not recommended that anyone enter the field until 9 a.m. Friday, but the workers entered sometime between 5:30 and 6 a.m.
As a result, they got secondary contamination, and two people experienced symptoms. That's when their supervisor called for help.
"The operation was stopped and everybody got out of the field immediately and that was the right thing to do, and we try to work as quick as we can but also while being safe to make sure everybody is cared for and taken care of as quickly as possible," Kings County Battalion Chief Blake Adney said.
Everyone was decontaminated and checked by emergency personnel.
Two people experienced headaches and some nausea.
They were not taken to the hospital but instead took themselves to a local clinic. All are expected to be okay.