Examples of fits of the CH bending band in the formamide:H₂O laboratory spectrum (in black, water contribution subtracted out) to the local-continuum subtracted observed spectra (in color) used to derive solid-state formamide upper limits. The peak position of the CH bend in the laboratory spectrum is marked with a dotted blue vertical line. These selected fits showcase the variation in the profile of the observed 7.24 μm band across the selected sources. In the observed spectra on the left, excess absorption on the blue wing of the observed 7.24 μm band allows for relatively high formamide upper limits (~≤1.5–5.1% with respect to H₂O), while the observed spectra on the right lack such a wing, resulting in lower formamide upper limits (~≤0.35–0.68% with respect to H₂O).