From the Texas Medical Association COVID-19 Task Force: Decision Tree for COVID-19 Exposure
Exposure: This means you were within 6 feet of someone who tested positive (and was contagious*) for more than 15 minutes with or without wearing a mask.
*People are contagious two days before they started having symptoms until at least 10 days after they started having symptoms. People who have no symptoms are considered contagious starting
from two days before they got tested, through at least 10 days.