Nothing makes a woman feel as sexy as a slimming, golden tan. And owing to awareness of the harm caused by the sun’s UV rays, fake tan and its just-back-from-the-Med glow have never been more popular. One in three women now use fake tan products and the industry is worth £100 million a year – with sales rocketing 38 percent over the past year alone. And with formulations improving all the time, orange streaks, blotchy legs and stained hands are less of a worry. It would seem we’ve finally got this tanning lark cracked. Or have we? For ask around, and users have all manner of health concerns, ranging from wrinkles to skin irritation and cancer. Added to this, experts aren’t convinced ingredients in fake tan – or the methods of application – are good for us. That’s because fake bakes work by reacting with your skin’s outer layer, which is mainly comprised of dead skin cells. Known as the Maillard reaction, it creates compounds that turn the cells brown. The active ingredient in this reaction is dihydroxyacetone, or DHA. Derived from sugar beet or cane, it’s been used since the ’20s as a skin colorant. It is also responsible for giving fake tans their characteristic biscuit smell. While dermatologists and cancer experts agree artificial tans are safer than real ones, they are still not risk-free. The Maillard reaction causes oxidative stress – a type of damage much like you’d get from pollution or even sunbathing – in the superficial layers of skin. “We don’t know the long-term effects,” says Dr Stefanie Williams, dermatologist and founder of London’s Eudelo skin clinic. “They may be insignificant, but oxidation is linked to ageing and disease.” In other words, fake tans may cause lines, wrinkles and sagging by damaging the skin – which users wanted to avoid by staying out of the sun. But is DHA safe? A review in 2012 suggested it could cause DNA damage, which is linked to cancer. Although a finding from animal cell tests, rather than human, toxicologists said it raised concerns. DHA was approved by the US Food & Drug Administration – a globally recognised benchmark of safety – for external use in the Seventies. But this excludes inhalation, which can happen when sprayed on to skin. Experts say this is where the biggest danger lies. Dr Williams says, “If DHA is inhaled into the body, or enters membranes in the eyes and mouth, it can reach cells in the respiratory tract and lungs.” In 2012, Dr Rey Panettieri, a toxicologist and lung specialist, warned, “The lungs have a huge surface area and these compounds could get into the bloodstream and promote the development of cancers. Regular inhalation could potentially lead to cancer or the worsening of asthma or other lung disease.” He added the risk was highest for people having regular spray tans or the staff applying them. Spray booths should have adequate ventilation, and the FDA recommends wearing eye protection, nose filters and a mask over the mouth. But those measures are rarely taken, not least because they’d cause some very strange tan lines on your face. “There’s no conclusive evidence that spray tans are dangerous or safe,” says Dr Williams. “But I’d advise against regular visits.” So are lotions, gels, mousses and creams safe? Again, say critics, that depends. “As a cancer-causing agent, there are no issues with DHA applied externally,” says cosmetic scientist Ian Taylor. “It’s the other ingredients that can creep into the production process that may cause problems. Cheaper processes using synthetic raw materials, such as solvents, may result in accidental contamination. So the resulting product may end up containing harmful ingredients.” A plant-based tanning agent called Erythrulose lacks the biscuit smell and seems less streaky. It’s often found mixed with DHA, but it’s hard to find products that use it alone. “Erythrulose typically takes longer to develop, has a less intense colour and doesn’t last as long,” says Taylor. Wash-off products are another option. They’re essentially make-up – a bronzer or tint that doesn’t dye the skin. Some products contain penetration enhancers, such as ethanol alcohol, which are designed to speed up or deepen the tanning process. But Taylor says they can disrupt the skin’s barrier, “increasing moisture loss and making skin more vulnerable to pollutants”. This can result in dryness, irritation – and wrinkles. Lots of moisturiser is therefore a must if you use fake tan, says Dr Williams, as well as exfoliation beforehand. As for skin irritation, there have been extreme reactions. This year, Kirsty Reeves, 27, of Essex, told how St Tropez Dark Bronzing Mousse left her face bright green.