c2d Spitzer survey of interstellar ices. I.

The sample is complemented with previously published Spitzer spectra of background stars and with ISO spectra of well-studied massive YSOs (L~10^5^L_{sun}_). The long-known 6.0 and 6.85um bands are detected toward all sources, with the Class 0-type YSOs showing the deepest bands ever observed.

The 6.0um band is often deeper than expected from the bending mode of pure solid H_2_O. The additional 5-7um absorption consists of five independent components, which, by comparison to laboratory studies, must be from at least eight different carriers. Much of this absorption is due to simple species likely formed by grain surface chemistry, at abundances of 1%-30% for CH_3_OH, 3%-8% for NH_3_, 1%-5% for HCOOH, ~6% for H_2_CO, and ~0.3% for HCOO- relative to solid H_2_O.