Our team decided to perform air quality testing before occupancy on a recently completed building. We have had some question over which method is required for tVOC testing and for what compounds. The manual states that the testing protocols should follow the guidelines in the EPA Compendium of Methods for the Determination of Indoor Air Pollutants. This guide references methods IP-1A and IP-1B for tVOCs, however when we got the results back from the lab, they referenced method TO-15 and included a separate list of compounds called Tentatively Identified Compounds (TICs). The TO-15 method comes from a much later EPA publication, the Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air. So now we have two VOC totals - one tVOC without TICs and another tVOC with TICs included. The list of VOC compounds in the TO-15 method contain the same compounds as listed in the IP-1A and IP-1B methods. None of the three methods talk about or list the TIC compounds. Are TICs required to be included in tVOC?