In many national and international programs, where thousands of chemicals are screened, the relative ability of a chemical to be transported over long distances can be an important criterion in determining whether concern is warranted.  Preliminary screening can be conducted in terms of the effective travel distance (ETD), the characteristic travel distance (CTD) or the degradation half-life in air.  However, despite their relative merits, the use of multimedia screening approaches like the ETD and CTD is often inhibited by the limited availability of degradation data (for air and water, but particularly for soils and sediments).  Preliminary screening in terms of the atmospheric degradation half-life alone therefore remains the most practical approach.  The relationship of these three screening approaches and their suitability for screening is both theoretically and empirically evaluated in this paper.  A technique to reduce the degradation data requirements of multimedia measures like the ETD and CTD by approximately 64% is introduced and a screening methodology consisting of three tiers is proposed.  It is demonstrated that the predictions at each tier are conservative (no false negatives) but that the number of false positives is reduced with both increasing degradation data requirements and model complexity.