Difference between the measured O/Hs of z ∼ 0.2 cluster galaxies and the expected O/Hs from the formulations of Lilly et al. (2013) for three regions at different distances from the cluster center (red, green, and blue) and field galaxies (cyan). The median value of the differences in metallicities of Mlow cluster galaxies inside R₂₀₀ (large red filled circle) indicates that measured O/Hs are higher inside R₂₀₀ compared to the Lilly et al. (2013) predictions with inflow of pristine gas. The median O/Hs of Mlow field galaxies (large Mlow cyan filled circle) and the median O/Hs of Mlow cluster galaxies at R >  R₂₀₀ are quite consistent (1.3σ) with the predictions. This indicates that the environment has an influence on gas metallicities with slow quenching (strangulation) likely initiated when galaxies pass R₂₀₀.