Yes, although in theory a threefold substitution is possible, the replacement should be process-specific.
Thiourea Dioxide is a powerful reducing agent that becomes strongly reducing under alkaline and elevated-temperature conditions. It can therefore be evaluated as an alternative to sodium hydrosulfite in:
Polyester reduction clearing
Disperse-dye stripping
Dyeing-machine cleaning
Color correction
Textile reductive bleaching
Selected pulp/paper deinking and bleaching applications
Published technical literature also identifies thiourea dioxide as one of the major reductive stripping agents alongside sodium hydrosulfite.
Recommended test starting point: do not replace 4 kg sodium hydrosulfite with exactly 4 kg Thiourea Dioxide. Start with a laboratory dosage matrix and optimize according to residual color, whiteness, ΔE, fastness and fabric strength.
Send us your current sodium hydrosulfite recipe. We can design a Thiourea Dioxide replacement trial and provide free samples for laboratory evaluation.