Titanium Dioxide in Foods and Cosmetics

It’s everywhere, from candies to paints, to toothpaste, sunscreens and mineral foundation. Is it safe? And does titanium dioxide (TiO2) equates to nanoparticles?

For years I entertained the reassuring idea that most TiO2 applications involve fairly large particles of this substance. After all it’s only sunscreens that require invisible, nano-form TiO2. The food industry uses this mineral as a colouring agent – to make the milk look  whiter and the marshmallows shimmery. If it’s opacity and coverage you’re after, nano particles, being transparent, are useless. The same applies to most cosmetic applications – mineral make up, toothpaste and many other toiletries. So manufacturers don’t need TiO2 in nano form for anything except sunscreens. Right? Well, not quite. Although nano TiO2 is not useful as a colouring agent, recent research has nevertheless found that about 36% the particles in food grade TiO2 is nano size. Research info

In view of this find, the question about nano TiO2 becomes even more important.

TiO2 nanoparticles in food

There is conflicting research data on the effects of ingested TiO2 nanoparticles. A few experiments have shown that ingested titanium dioxide does not get absorbed from the guts into the bloodstream. These are the experiments which have informed the decisions of food industry regulators to approve TiO2 as a colouring agent. More info

However, a more recent study has concluded that ingested nano TiO2 induced DNA damage and genetic instability in mice. Research info 

Also, a few scientists have broadened the discussion to include questions like:

  • What is the long term, cross-generational  effect of exposure to nano TiO2?
  • What effects do nanoparticles have on the gut absorption of nutrients?

We do not know the answers to these questions specifically for humans exposed to dietary TiO2, but a couple of experiments have shown surprising results, highlighting our lack of knowledge on long term effects of nanoparticle ingestion:

  • An experiment on water fleas has shown increased sensitivity to TiO2 nanoparticles in the next generation although the parents did not display any adverse reaction to the substance. More research info
  • An experiment on chickens has revealed that ingesting polystyrene nanoparticles affect the uptake of iron in the gut.  More research info

Since TiO2 is of no nutritional value whatsoever, I can’t help wondering: Is any level of risk worth taking just for the sake of colouring our food with white pigment? If you take the view that this is an unwarranted risk, you can avoid foods containing TiO2. That is if you are prepared to check on ingredient lists. TiO2 appears on food labels as E171.

TiO2 nanoparticles in cosmetics

More than one experiment has shown that nano TiO2 is not absorbed through healthy skin. (Research details 1 and 2) The research data available at this point consistently supports the idea that the risk posed by TiO2 as a sunscreen ingredient in creams and lotions is negligible.

TiO2 in sprays and loose powders TiO2 is not as safe - there is evidence that inhaling TiO2 nanoparticles causes pulmonary emphysema (research details). Moreover, titanium dioxide particles of various sizes (nano and above) are a known hazard to workers in factories processing this substance. Of course applying powdered foundation or sunscreen is not the same as prolonged exposure in a factory. The question remains open as to how many times you can breath in mineral powders before your exposure to TiO2 becomes significant. Balance this against the preservatives and other questionable ingredients in many creams and lotions and the healthiest choice is not so obvious.

Environmental concerns

Worldwide production of TiO2 is on the up. We are dumping increasing amounts of TiO2 nanoparticles into the environment. Experiments on water fleas (link as above) and woodlice (research info)  have shown these organisms to be affected by nano TiO2. The truth is we have no idea what long term effects nano TiO2 waste may have on the environment.

Many scientists agree that lot more research on this issue necessary. TiO2 it is clearly useful as a UV blocker (there are a lot worse sunscreen ingredients in use today) and there are countless other useful applications. It is the nano TiO2 that raises the difficult questions. Will we be able to limit the more superfluous applications (e.g. food pigment)? Could we reduce the number of nanoparticles we are releasing into the environment mixed with the larger, safer ones?

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