Development of a process for obtaining non-mutagenic madder root (Rubia tinctorum) extract for textile dyeing

•Exposure to mutagenic anthraquinone compounds of madder dye extract is not a fact.•A safe madder dye was obtained by optimizing several process parameters.•The process was carried out both at lab scale and 5000 L industrial scale.•Through Ames bioassay-guided fractionation all mutagenic compounds were identified.•Migration of anthraquinones while wearing clothes dyed with madder is zero.