Having tackled skin lighteners I thought I had better write something about the opposite. Most people on the planet want to look paler, but here in the UK quite a lot of us want to look darker. You are saying that you are a member of the jet set just back from your latest trip to sunnier climes (which compared to Britain is just about everywhere).
Whitening the skin is a difficult thing to do safely and effectively and skin lighteners throw up all kinds of practical and ethical issues. Producing a fake tan on the other hand is a very straight forward, cheap and safe process. The only drawback is that it is a rather haphazard process that isn’t perfectly controllable. In some cases the results can border on the alarming. One fake tan fan I know usually comes out in a virulent shade orange. I wonder if having a chat with her counts as one of my five a day?
The reason for this wide person to person variation in how they work is down to the basic chemistry behind them. There are a number of chemicals that can be used to give a tanning effect, but one of them – dihydroxyacetone – is so much more effective than the others that it is almost universally found in commercially successful fake tans. This works by reacting with the proteins that are found in the upper layers of the skin.
The chemistry is quite interesting. What is going on is very similar to a process called Maillard browning. This is a very familiar every day happening, even if you haven’t heard the term before. If you bite into an apple and leave it a while it starts to go brown in places. The sugar in the apple is reacting with its proteins in the presence of oxygen. A lot of the brown colours you get in cooking and baking arise in the same way.
Although dihydroxyacetone isn’t actually a sugar chemically it is similar to one, and undergoes something very much like Maillard browning. Being a very reactive chemical, it reacts very quickly and doesn’t get past the upper layer of the skin. If any does it is quickly and easily mopped up by the body’s enzymes. So whatever else you think about fake tans, they are certainly safe.
The smell some people complain about is a side effect of the reaction – but most products have fragrances that mask it well enough.
The contrast between skin lighteners and fake tans is a striking one. Skin lightening products raise all manner of safety and ethical issues. The worst risk with a fake tans is becoming a laughing stock if you overdo it. One thing to note is that the colour you achieve is to a large extent controlled by your own particular skin chemistry. People who end up looking like they have been sponsored by the Satsuma Marketing Board generally do so because of the particular arrangement of amino acids in the proteins in the upper levels of their skin. Having said that, a degree of lack of self awareness probably is a factor. I think laughing at them is still legitimate – especially when they make a living on daytime television.
But for most people you can get pretty good results with fake tan. It does take a bit of practice to get just the effect you want. The reaction takes about an hour to fully develop so putting it on for the first time is a bit like trying to write with your eyes closed. Most formulatons will give good results if you apply them evenly, but some are easier to apply than others. You get most control from formulations that combine the ability to flow easily with the property of not moving much when you leave them be. The technical term for this is thixotropy, and a highly thixotropic formulation will give least streaking and the most even application. Another familiar example of a thixotropic product is tomato ketchup. It spreads easily onto your chips and then satisfyingly stays there while you eat them.
Fake tans are one of life’s great pleasures. You can get that sun soaked look without all that tedious lying around in the sun. I am sure I don’t need to remind readers of this blog that they don’t confer any protection against the sun. They are a more healthy option than using a tanning bed. UV radiation is definitely a cause of skin cancer quite apart from causing premature ageing. You might find yourself living with the consequences of overusing a sun bed for years to come. By contrast, once a fake tan has faded, it has no further effect. You can reapply it if you want to, or revert to your natural colour.
The Scientific Committee on Consumer Safety of the EU has extensively reviewed the safety of dihydroxyacetone and found it to be safe. You can find their full reasoning here.