Solid hydrogen is a volatile material. In its pure form it would sublimate rapidly under typical interstellar conditions, so it is widely believed to be absent from the diffuse ISM. But dust particles acquire surface charges, and for H2 these charges greatly attenuate the sublimation rate. It now appears possible for hydrogen grains to survive in the diffuse ISM, so their presence or absence has become an observational issue. Is it possible that solid H2 is a major component of interstellar dust?