A paper in the most recent International Journal of Cosmetic Science has just drawn attention to a little noticed issue that has been bubbling away in the background of the cosmetic science world for a while. The issue is the use of long chain hydrocarbons in lip products. This sounds pretty formidable, but it is not really that complicated. Mineral oil is largely composed of long molecules that are composed of nothing more than chains of carbon atoms surrounded by hydrogen atoms. This is about as simple as chemistry gets, and the chemistry of hydrocarbons has few surprises. The most interesting thing about them is that they make a good source of fuel. And the biggest use we put them to is to put them into cars and aeroplanes.
In principle they can also be a source of fuel for humans as well. The body is capable of breaking down hydrocarbon chains to provide an energy source at a pinch. But our metabolism is much better suited to using fats. Fats as it happens are pretty closely related to hydrocarbons. The difference is that in fats the hydrocarbon chains have an acid group on the end. As we tend to eat fats from animal and plant sources rather than eating hydrocarbons our bodies have got all the enzymes they need to efficiently process fats with their acid groups. We do a much worse job of dealing with the rather simpler hydrocarbons.
The upshot of this is that if we ingest hydrocarbons, they tend to get stored rather than used. This has been used in the past to produce slimming products. If you replace fat with a hydrocarbon then you can eat a lot more calories without putting on weight. This approach is now out of fashion, and I have a feeling it would probably now be illegal, though don’t quote me on that.
Mineral oil isn’t the only source of hydrocarbons. You get them from quite a lot of natural sources as well. People haven’t really given them too much thought in the past. When I was a kid it was routine to coat raisins in mineral oil to stop them sticking together. They don’t do this any more, and raisins taste a lot better – but they tend to stick together. There were other food uses of mineral oil as well, and you can still get what are called food grades. But the use of mineral oil as a foodstuff has become much less fashionable and it is now no longer approved as a food additive. That doesn’t necessarily mean you aren’t eating it though, because it remains approved for use in food processing. I’m not a food scientist and I really don’t know how widespread this use is, but it is common enough to trouble the EFSA Panel on Food additives and Nutrient Sources added to Food to carry out an investigation into its safety.
The problem is basically the slow speed at which the body processes hydrocarbons which in turn leads to them tending to accumulate in the body. It isn’t at all clear that this has ever done any particular harm to anyone, but it is the sort of thing that raises alarm bells. Mice have been fed quite large quantities without any obvious ill effect. But that doesn’t mean that in a larger animal like a human that adverse effects of a subtle nature won’t occur. In fact it is quite easy to come up with plausible harmful effects. Do they prevent the absorption of important vitamins? Do they form oil droplets that can block important processes? Do they interfere with important enzymes?
In all likelihood this is one of those cases where the dose makes the poison. There is probably no harm in small quantities, but if you put enough into your diet you might well find that at some point your body can no longer cope with it. The trouble is that this is exactly the kind of thing that animal testing is rubbish at determining. It is really hard to extrapolate from one species to another if you aren’t even very sure what it is you are looking for in the first place. And you can’t really do this kind of testing on humans either. Feeding people mineral oil until they start to show symptoms isn’t going to get past any ethical review process.
So not surprisingly the food regulators have played it safe and just banned the stuff. It isn’t as if there are no alternatives. This sounds like a good decision to me. I can easily believe that a small amount mineral oil won’t do me any harm, but the idea of eating it just doesn’t appeal to me.
The same issues don’t arise in cosmetic products that are applied to the skin. Hydrocarbons with long chains don’t really get through the skin, and the short chain ones are much less of a problem anyway as they can be processed much more quickly. But what about lipsticks and lip balms? On the face of it, these don’t really represent any big issue. You don’t apply very much of them, and most of what you do apply isn’t ingested in any case. So until relatively recently nobody took too much notice.
But in 2014 Cosmetics Europe, the trade body for the European cosmetic business issued some recommendations on the subject. These are just what they say, recommendations. Cosmetics Europe is a worthy and respected organisation that does a lot of good work. But it doesn’t have the power to pass laws. And as recommendations go it was, how can I put it, not especially decisive. It simply said that only hydrocarbons for which an Acceptable Daily Intake (ADI) had been determined should be used. It also defined the hydrocarbons that it was talking about, so it only applies to relatively long chain ones.
This was all sensible enough, except that ADI figures for mineral oil grades are thin on the ground and when they do exist aren’t always recognised as particularly useful. In a review of the use of mineral oil in food, the European Food Standards Agency managed to assign an ADI to one type of food grade mineral oil, but the caveats and disclaimers filled nearly half a page.
So where does this leave the consumer? My summary is that mineral oil is a bit yucky and I don’t think I want to use lip products that contain it. But it seems vanishingly unlikely that you are going to get any kind of harm from it. The ADI I mentioned above is way higher than even the most hardened lipstick enthusiast is going to get anywhere near. So if you have a favourite product that uses mineral oil you haven’t done yourself any harm and you can carry on using it without any need to worry. If like me you just don’t like the idea, here are the ingredient names to look out for –
And if you really, really dislike the thought of hydrocarbons they are pretty high in candelilla and carnauba waxes as well – though these aren’t mineral oil derived.