Toxic chemicals in fast fashion supply chains: Risks, impacts, and regulation 

What are toxic chemicals in fast fashion?

The term “toxic chemicals” refers to substances that are hazardous to human health or the environment. In the fast fashion industry, these may include: 

• Azo dyes that release carcinogenic aromatic amines during degradation 

• Heavy metals such as lead, mercury, and cadmium used in dyes and finishes 

• Formaldehyde, used for wrinkle resistance 

• Phthalates used in prints and plastics 

• Per- and polyfluoroalkyl substances (PFAS) used in water- and stain-resistant treatments 

• Pesticides and synthetic fertilizers used in cotton cultivation 

In some cases, residual amounts of these substances may remain in finished garments and are not fully removed before clothes reach store shelves – an issue explored further in what’s hiding in your textile products. The result is that consumers may be exposed through skin contact or inhalation. 

How toxic chemicals enter fast fashion supply chains

Fast fashion relies on complex, globalized supply chains across multiple countries and production stages. Toxic chemicals can be introduced at nearly every step — from fiber cultivation to finishing and transport. 

Raw material production 

Chemical inputs begin at the fiber stage. 

Conventional cotton cultivation can involve intensive pesticide and fertilizer use, creating exposure risks for agricultural workers and nearby communities through spray drift and groundwater contamination. 

Synthetic fibers such as polyester also involve chemical-intensive manufacturing processes. Derived from petrochemical feedstocks, they may incorporate flame retardants, plasticizers, or other additives during production. 

Textile manufacturing and dyeing  

As fibers are spun, woven, and dyed, additional chemical inputs are introduced. 

Lubricants and solvents may be used during the spinning or weaving process, many of which contain harmful chemicals.  Dyeing uses large quantities of dyes and processing chemicals. Where wastewater is not properly treated, contaminated effluent can enter rivers and streams, carrying heavy metals and other hazardous substances.  

Finishing treatments add features such as wrinkle resistance or water repellency. To achieve these effects, manufacturers may use chemicals including formaldehyde or PFAS — substances that can be difficult to break down in the environment. 

Printing, decoration, and transport 

Decoration and finishing processes can further increase chemical complexity. Plastisol inks used in graphic prints may contain phthalates. Metallic finishes may involve heavy metals. During storage and international transport, garments may be treated with biocides to prevent mold growth in humid conditions.  

Structural drivers within the fast fashion model 

Beyond individual production steps, the fast fashion business model can influence how chemicals are selected and managed. 

Short production timelines can limit opportunities to reformulate or transition to alternative processes, particularly as chemicals and EPR regulations are increasingly shaping textile production requirements. Cost sensitivity across supply chains may constrain investment in advanced wastewater treatment or chemical substitution. High production volumes amplify total chemical use and environmental releases, even when per-garment inputs decrease. 

Global outsourcing adds another layer of complexity. Oversight, enforcement, and chemical management practices vary by region, making consistent implementation challenging across dispersed supplier networks. 

As a result, achieving full transparency and chemical control across the entire supply chain remains a persistent industry-wide challenge. 

Environmental and health impact of toxic chemicals in fast fashion

Fast fashion’s chemical footprint creates consequences that extend beyond factory walls. From polluted waterways to occupational health risks, the impacts affect ecosystems, workers, and consumers throughout the product lifecycle.

Environmental impacts 

The environmental toll of toxic chemicals in fast fashion is significant.  

Textile dyeing is widely cited as a major contributor to global industrial water pollution, second only to agriculture. Dye effluent discharged from factories without adequate treatment can contaminate waterways, affecting drinking water supplies and aquatic ecosystems. Persistent substances such as heavy metals may accumulate in soil and sediment, adversely affecting agricultural crops and biodiversity.  

Volatile organic compounds (VOCs) released from solvents and antimicrobial treatments contribute to air pollution and reduced air quality in manufacturing regions.  

Environmental impacts are not limited to manufacturing regions only. Pollution can travel through air and water currents, and garments may continue releasing microplastics and chemical additives during washing throughout their lifecycle 

Worker and consumer health risks 

Workers in textile factories face the highest risk of adverse effects from chemical exposure. Inhalation of dye powders and formaldehyde fumes may contribute to respiratory problems. Direct contact with acids and solvents can cause skin irritation or burns. Prolonged exposure to certain azo dyes and heavy metals – including substances discussed in our analysis of carcinogenic chemicals in textiles – has been linked to increased cancer risk over time. 

Consumers may also encounter residual substances in finished garments.  Studies have identified detectable levels of formaldehyde, phthalates, and azo dye byproducts in clothing sold in major stores. While concentrations are typically low, repeated dermal exposure may raise concerns, especially sensitive populations like infants and children. 

Regulatory efforts and voluntary efforts to address toxic chemicals in fast fashion

Governments, regulators, and industry initiatives have introduced measures to limit toxic chemicals in fast fashion supply chains:

• EU REACH restricts hazardous chemicals in products sold in the European market.

• California Proposition 65 requires warning labels for products containing listed carcinogens and reproductive toxicants above specified thresholds. 

• Regional wastewater standards, such as those enforced in Zhejiang Province (China), impose stricter discharge limits on textile dyeing facilities.  

• Emerging policy discussions, including calls for tighter chemical recycling rules, signal growing global scrutiny of textile chemicals.  

 Voluntary standards and industry initiatives also tackle the issues:  

• ZDHC (Zero Discharge of Hazardous Chemicals) operates a voluntary Manufacturing Restricted Substances List (MRSL) used by brands and suppliers worldwide. 

• OEKO-TEX® certification limits chemical residues in finished garments. 

Why regulatory oversight and voluntary standards both matter

Despite these efforts, regulatory enforcement and chemical oversight still vary significantly across jurisdictions. Many brands source from regions where enforcement and monitoring are weaker, and voluntary initiatives vary in uptake and transparency.  Continued progress will depend on stronger enforcement, broader adoption of best practices, and greater supply chain accountability. 

Brands can strengthen chemical management by auditing suppliers, requiring wastewater treatment and disclosure, and by adopting voluntary standards such as the ZDHC MRSL. Investment in cleaner production technology, such as waterless CO2 dyeing, or lower toxicity plant-based dyes and finishes – can further reduce reliance on hazardous substances.

The long view: Reducing toxic chemicals in fast fashion

Toxic chemicals in fast fashion supply chains remain a systemic challenge. They contribute to water pollution, create occupational exposure risks, and may leave residues in garments worn by consumers.  

Addressing these risks requires coordinated action across the value chain. Brands can strengthen supplier audits, require chemical disclosure, and invest in cleaner production technologies such as improved wastewater treatment, alternative dye systems, or lower-toxicity finishing processes. Policymakers can enhance regulatory harmonization and enforcement. Consumers can support greater transparency and responsible purchasing decisions. 

As awareness grows, continued progress will depend on integrating stronger chemical oversight, improved transparency, and safer production practices throughout the global fashion value chain — helping align industry growth with environmental and public health priorities.