Vapor intrusion determinations, real estate transactions, remediation decisions, and regulatory closures often hinge on a single question:
Is the air data defensible?
For decades, EPA Method TO-15 has served as the backbone of VOC air testing nationwide. Its broad compound coverage, regulatory familiarity, and analytical consistency have made it the reference method for vapor intrusion, indoor air quality, and environmental due diligence investigations.
TO-15 is a standardized GC/MS method that measures a predefined list of VOCs in ambient, indoor, and sub-slab air, most commonly using passivated stainless-steel (Summa) canisters. When applied correctly, it delivers low-level sensitivity and comparability across projects—providing a common technical language for consultants, regulators, and laboratories.
But TO-15 is not just a laboratory method it is part of an integrated sampling system.
Canister preparation, flow control, sampling duration, and field conditions all directly influence data quality. When sampling execution is aligned with site conditions, TO-15 provides reliable, decision-quality results. When it is not, uncertainty can persist regardless of method compliance.
This is why TO-15 performs best when target compounds fall within its defined analyte list and behave predictably in whole-air sampling systems. In more complex chemistries, alternative approaches such as sorbent-based sampling or TO-17 may be appropriate complements.
At AmSpec, TO-15 remains a foundational air-testing method across industrial, commercial, and regulatory-driven projects—selected not by habit, but by fit.
When air data carry regulatory, financial, or risk-management consequences, TO-15 provides a proven analytical foundation—when sampling strategy and site conditions are given equal consideration.
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