The deep amber hue of a freshly brewed cup of tea is considered a marker of quality, strength and freshness. But what if that colour is manufactured and toxic? The recent seizure of 3,000 kg of adulterated tea powder and 1,500 kg of expired tea powder in Hyderabad pulls back the curtain on a food scam: Using synthetic dyes to make inferior or even expired tea look premium.The accused procured low-quality tea powder from vendors in Kolkata, Kerala and Assam and adulterated it with synthetic dyes like Sunset Yellow FCF and Tartrazine before repackaging it under different brand names and selling it as genuine product, police said. Here’s how they can affect your health.Sunset Yellow FCF: When appearance overrides safetySunset Yellow FCF, a synthetic azo dye, is commonly used to impart a warm orange-yellow tint to processed foods and pharmaceutical products. In regulated quantities, global food safety authorities consider it safe. However, its presence in tea is a clear violation, since tea is not a category where such colouring agents are permitted.What makes Sunset Yellow particularly concerning is not just its misuse, but the spectrum of health effects associated with it. In sensitive individuals, it has been linked to allergic reactions ranging from mild itching and hives to nasal congestion and eczema. Over the years, scientific studies have also raised questions about its role in behavioural changes among children, especially increased hyperactivity. While the evidence is still debated, the concern has been strong enough to influence labelling norms in several countries.Emerging research has also explored how long-term consumption of such dyes may affect gut health, potentially altering the balance of beneficial bacteria and weakening intestinal integrity. Animal studies have pointed to possible immune suppression and, at very high doses, damage to organs like the liver and kidneys. Regulatory bodies maintain that these risks are associated with excessive intake, far beyond permitted levels.From a regulatory standpoint, the Food Safety and Standards Authority of India permits Sunset Yellow FCF (INS 110) only in specific categories of processed foods and within strict limits. It must meet high purity standards, be free from toxic contaminants, and be transparently declared on product labels. Crucially, its use in tea is not allowed, making its presence in the seized stock a textbook case of adulteration.Tartrazine: A familiar additive with unfamiliar risksTartrazine, another synthetic dye identified in the Hyderabad seizure, is widely used to give foods and beverages a bright lemon-yellow colour. Like Sunset Yellow, it occupies a legally permitted space in the food industry but within strict limits.Story continues below this adThe controversy around Tartrazine largely stems from its potential to trigger allergic reactions. For some individuals, particularly those with aspirin sensitivity, it can cause hives, skin rashes, and even respiratory symptoms such as asthma. Concerns have also been raised about its possible link to hyperactivity and attention-related issues in children, echoing findings associated with other azo dyes. Scientific investigations into high consumption levels have gone further, suggesting possible oxidative stress and adverse effects on organs in experimental settings.Under FSSAI norms, Tartrazine (INS 102) is allowed in certain processed foods such as flavoured drinks, confectionery and desserts, subject to maximum permissible limits. Like all synthetic colours, it must be clearly labelled and adhere to stringent purity criteria, including limits on heavy metals. Its use in tea, however, falls outside these permitted categoriesThe hidden danger of expired teaThe seizure also included a significant quantity of expired tea. Now tea may not spoil in the same obvious way as perishable foods, but over time, especially when stored in humid or unhygienic conditions, it can become a breeding ground for mold and bacteria. For individuals with allergies or compromised immunity, this can cause digestive discomfort. Besides, expired tea gradually loses its beneficial compounds, particularly antioxidants that are central to its health appeal.Next time, watch the colour of tea. It should not be instant or unnaturally bright, and packaging should always be scrutinised for transparency.