Sudan dye contamination in Indian chilli and turmeric: What consumers need to know

Concerns over food safety have resurfaced after multiple international regulators flagged the presence of Sudan dyes, industrial colourants banned for use in food, in consignments of Indian spices, particularly chilli powder and, to a lesser extent, turmeric.

Over the past few years, a growing number of border rejections, recalls and advisories issued by agencies in the European Union, Singapore and Hong Kong have pointed to recurring contamination, prompting tighter scrutiny of Indian spice exports and renewed questions about adulteration controls at home.

What are Sudan dyes, how are they used illegally in food, and what health risks do they pose?

Sudan dyes are a group of synthetic, fat-soluble azo compounds, most commonly Sudan I, II, III and IV, originally developed for industrial use. They are used to colour plastics, textiles, waxes, oils and petroleum products, and are also employed in laboratories to stain lipid-rich samples. Because of their vivid red-orange hue and low cost, these dyes have been illegally used to enhance the colour of food products, particularly spices such as chilli, paprika and curry powders, as well as sauces and palm oil.

Also read | How customs duty exemption on 17 cancer drugs will impact patients

Their presence in food poses serious health concerns. Sudan dyes are classified by the International Agency for Research on Cancer (IARC) as Category 3 carcinogens and are banned as food additives in many jurisdictions, including the European Union and the United States, due to their carcinogenic and genotoxic potential. Food safety authorities routinely monitor for these compounds, especially Sudan I to IV, using analytical techniques such as high-performance liquid chromatography (HPLC) and mass spectrometry, as they are among the most frequently detected illegal dyes in imported and domestically sold spices.

Sudan dyes were named so to evoke a sense of exoticism and the intense, fiery red-orange hues they produce. The name is not related to the country of Sudan; instead, it reflects the perceived “hot” and tropical imagery associated with the region, highlighting the dye’s vibrant colour.

Why is Indian chilli powder under global scrutiny for Sudan dye contamination, and what about turmeric?

A series of such cases were reported across the European Union, Singapore and Hong Kong between 2022 and 2024. In Singapore, the Singapore Food Agency (SFA) detected the presence of Sudan I and Sudan IV dyes in chilli powder imported from India. The findings led to the recall of multiple consignments, with importers also facing penalties. The SFA flagged Sudan dyes as illegal food colourants with carcinogenic potential, clarifying that the action was based on routine border surveillance rather than any targeted measure against India.

In Hong Kong, the Centre for Food Safety (CFS) found Sudan Red I in packaged chilli powder sourced from India. The affected products were withdrawn from retail shelves immediately. The CFS said the dye was likely added to enhance colour in low-grade chilli, a practice commonly associated with adulteration.

Under the European Union’s Rapid Alert System for Food and Feed (RASFF), several consignments of Indian chilli powder were rejected after tests detected Sudan I and Sudan IV contamination. Most of these detections occurred at ports in Italy, Germany and the Netherlands. Indian chilli is already classified as a high-risk product by the EU, requiring pre-export testing and certification before shipment.

While Sudan dyes are far less frequently detected in turmeric than in chilli, regulators have flagged related concerns. Food safety agencies in the UK and the EU have issued alerts over the presence of illegal dyes, including Sudan dyes and metanil yellow, in turmeric of South Asian origin, including India. Indian authorities have acknowledged that adulteration risks are higher in unbranded, loose turmeric, particularly at the retail level.

What steps have Indian regulators taken to curb the use of banned dyes in spices?

In India, the Food Safety and Standards Authority of India (FSSAI) has repeatedly warned spice manufacturers against the use of Sudan dyes, Rhodamine B and metanil yellow. Several state food safety departments, including those in Tamil Nadu, Telangana and Maharashtra, have seized chilli powder samples that tested positive for non-permitted dyes and filed cases under the Food Safety and Standards Act. Authorities have also tightened testing norms for export consignments of chilli and turmeric to curb adulteration.

Beyond issuing warnings and ordering seizures, the Food Safety and Standards Authority of India (FSSAI) has stepped up on-ground surveillance across the spice supply chain. State food safety commissioners have been asked to intensify inspections at spice grinding units, processing facilities and wholesale markets, particularly those supplying loose and unbranded chilli and turmeric powders. FSSAI has also launched periodic special sampling drives targeting high-risk products such as chilli powder, turmeric, curry powders and blended masalas, with random samples lifted from retail markets as well as manufacturing units.

At the regulatory level, the authority has expanded and upgraded its network of NABL-accredited laboratories to improve detection of synthetic dyes at lower thresholds, aligning testing protocols with international standards. FSSAI has also focused on capacity-building through its Food Safety Training and Certification (FoSTaC) programme, training food business operators, inspectors and laboratory personnel to identify chemical adulterants such as Sudan dyes. In parallel, it has issued consumer advisories urging people to avoid unnaturally bright spices and coordinated with customs authorities, APEDA and the Spices Board to strengthen traceability and compliance for export consignments, especially in the wake of repeated overseas rejections.

How does Sudan dye contamination affect consumers, and how can you protect yourself?

Even though most recent detections of Sudan dyes have occurred in exported consignments, adulterated spices can still make their way into the domestic market, particularly loose, unbranded chilli and turmeric powders. These synthetic dyes are added to enhance colour, making spices appear brighter than they naturally are, but long-term consumption poses serious health risks. Classified as carcinogenic and genotoxic, Sudan dyes can increase the risk of cancer and DNA damage, with children, pregnant women, and people with pre-existing health conditions being particularly vulnerable.

Also read | Chronic kidney disease affecting millions of Indians; doctors explain how to prevent

Consumers can take several steps to protect themselves. Choosing branded, packaged spices with the FSSAI logo and licence number is one of the most effective safeguards, as these products are more likely to be tested and certified. Spices that appear unnaturally bright or glossy should be avoided, as excessive colouring can indicate adulteration. Purchasing from trusted retailers rather than bulk or local markets reduces the likelihood of exposure.

In addition, proper storage and vigilance help minimise risk. Spices should be kept in airtight containers away from heat and moisture, and any suspicious products can be reported to local food safety authorities. By staying informed and making careful choices, consumers can enjoy their spices safely while the authorities continue efforts to monitor and curb the use of banned dyes.