Restricted substances, labeling, and material-content limits are cleared at material selection, not the week production starts. Inks, films, threads, foils, and trims are documented per program, with factory disclosure supplied alongside the quote.
Where it goes wrong: foil, reflective film, and plated trims are the usual late failures. Each one introduces a material a standard apparel submission does not cover, and finding that out at production means starting the gate over.