VOC testing frequency depends on the environment type, occupancy patterns, and contamination sources. New construction and renovated buildings should be tested before occupancy and again 3-6 months after completion when off-gassing from building materials peaks. Residential homes benefit from annual testing, with additional testing after major renovations, new furniture installation, or unexplained health symptoms. Office buildings should conduct baseline testing every 2-3 years with additional testing when introducing new equipment, furniture, or cleaning products. Healthcare facilities require more frequent testing every 1-2 years due to vulnerable populations and strict air quality requirements. Manufacturing facilities need quarterly or bi-annual testing depending on chemical processes and regulatory requirements. Schools and daycare centers should test annually to protect children who are more sensitive to VOC exposure. Any environment experiencing unexplained health complaints, new chemical odors, or significant changes in building materials should receive immediate testing regardless of scheduled intervals.