Using effective chiral Lagrangians, we consider the occurrence of quadratic terms in the ΔI=1/2 K→3π matrix element. The inclusion of higher-derivative Lagrangians leads to a significant improvement over the usual current-algebra analysis. This allows an extraction directly from experimental data of Λχ, a measure of the scale of chiral symmetry. We give an operational definition of the chiral scale, and find Λχ≈1 GeV. The issue of uncertainty in the phenomenological determination of the B parameter is clarified.