Acid dyes are extensively used for dyeing protein fibers and polyamides due to their affinity for amine groups and ability to produce intense, level shades. However, many conventional acid dyes contain sulfonated structures and auxiliary substances that present risks to aquatic environments when not properly treated. Additionally, some dye formulations may contain impurities such as aromatic amines or metal-based mordants, triggering regulatory and reputational concerns. Sustainability-focused dye manufacturers are innovating to improve dye exhaustion, reduce water and energy usage, and increase biodegradability. Modern acid dyes are engineered for high fixation rates and low salt dependence, improving process efficiency and minimizing dye loss in wastewater. Coupled with closed-loop water systems and improved filtration technologies, these dyes support cleaner production in compliance with environmental standards. Certifications like OEKO-TEX® and GOTS now scrutinize acid dye formulations for residual toxins and safe disposal potential. Brands sourcing textiles dyed with acid dyes must consider not only color performance but also chemical traceability and post-process water treatment. Sourcing platforms are instrumental in identifying acid dyes that balance color richness with compliance and environmental safety. These tools help technical and sustainability teams align performance with responsibility across fiber types and end-use applications.