Are glow-in-the-dark pajama safe?

Likely safe to wear. Glow-in-the-dark clothing is probably safe. The material that glows is not radioactive, and does not emit any light unless it first absorbs some light. Over time, the material fades as it emits out the light energy that it absorbed. Since glow-in-the-dark pajamas are a novelty item, they need not be used if one has concerns about long-term or environmental effects of glow-in-the-dark materials.