I enjoy being a cosmetic chemist, but like every job some things can be a bit tedious. None is more so than complying with legislation. In California they have a particularly irritating example of this in the form of a thing called Proposition 65, which includes a list of chemicals that California has decided are linked to cancer. If you sell a cosmetic containing any of these chemicals you have to go online and notify the state of this fact via a particularly user-unfriendly database. The list is quite long and is comprised mainly of chemicals I have never heard of, or that would have no use in any cosmetic product.
But I was surprised to see titanium dioxide listed. Surprised and annoyed actually, because it was one of only two ingredients on the list that were in products I was working on that were intended for sale in California. This meant that I had to register for the database and spend and very large amount of time filling in online forms. Nobody likes filling in forms at the best of times and this one was a stinker. The most frustrating bit was that you had to get in touch with the people who supply you with the ingredient and get them to confirm to you that what you are saying is correct, and to give the date you did it and their contact details. I suppose the intention is that somebody in California can check that you are not just making it all up.
This meant that not only was I wasting a lot of time, I was also wasting time of my friends in the business as well. And the state of California was officially treating me as if I was dishonest in the process. I had thought it was Europe that was supposed to be full of bureaucratic anti-business regulations? I thought Californians are all free thinking and entrepreneurial? Clearly not all stereotypes are accurate.
I was curious as to what exactly they thought was the problem with titanium dioxide. Knowing it to be an insoluble mineral with a very inert kind of chemistry that is widely used in pharmaceuticals as a colourant, I found it a bit surprising that there would be any question about its safety. So I did a quick google to see what the problem was. I wasn’t surprised to find plenty of scaremongers denouncing it. Any chemical that gets onto an ingredient list comes in for that kind of treatment. But it turned out that there was indeed a proper scientific paper linking titanium dioxide to lung cancer. This came from the occupational health literature and related to experiments on titanium dioxide dust. They were investigating how much dust could be safely permitted in factories where titanium dioxide was being made.
It turned out that breathing in high levels of titanium dioxide dust could indeed cause lung cancer in lab animals. There was no sign that the same happened in humans, but nonetheless it does show that like most things titanium dioxide can be harmful if handled badly. It also shows that a lot of work goes into making sure that workers are safe nowadays, which is a good thing. If I was responsible for a plant where fine dust particles were being produced, whatever they were made of, I’d be looking at the details of that study closely.
What it doesn’t suggest is that using titanium dioxide poses any risk when used in cosmetics. Indeed it strongly suggests exactly the opposite. If you have to grind it up and breath it in to do any damage, it hardly poses a risk in normal use. I find the approach of the California state legislature here to be bordering on the passive-aggressive. If they think something is carcinogenic, then get on with it and ban it. I may not agree, but if you really think that the link between titanium dioxide and cancer is serious then surely you shouldn’t be allowing it. Getting manufacturers to fill in tedious databases hardly seems like an appropriate response.
I have done a more general post about titanium dioxide.
Baan, R., et al. Carcinogenicity of carbon black, titanium dioxide, and talc. The Lancet Oncology. Vol. 7 (Apr. 2006). P. 295-296
(This paper is free but you have to register with the Lancet.)
The EU official name for titanium dioxide is CI 77891 – you’ll see that on a lot of ingredient lists.