Sodium lauryl sulphate (SLS) is a common component of our toothpastes and shampoos. It is responsible for the foaming action... is it necessary? is it harmful, does it cause cancer? should we use it or not? I have been trolling the literature and research to try and find some evidence for its sinister reputation.
I am afraid there is very little. There are no articles that have been correctly refereed (meaning that the articles are peer reviewed and have been carried out with correct scientific protocol) that substantiate the cancer causing effects of SLS. At it's worst, it is a skin irritant. It has been used in many cancer testing experiments because it dissolves the agents being tested well and assists in the experiment. Yes it is an irritant, and as with most chemicals natural or otherwise if you put it in your eye it will have a negative effect. What I have found is that many "natural, organic, health" companies use the urban myth to fan a niche market for themselves. They all cite the one article which has absolutely no scientific merit.
Having said that is having SLS in your toothpaste necessary. SLS's work by emulsifying oil and water. This lowers the surface tension and allows better penetration, it also is useful for stopping a mixture separating into is components. Is its's foaming action important in helping us clean our teeth? My personal opinion is that it is a very minor factor in the benefits of toothbrushing. The mechanical action of the bristles is much more important. Plaque is extremely easy to remove when it first forms, a bit like fairy floss, just the action of the bristles are effective. Dental Care Products does stock a SLS-free toothpaste Closys but we stock it for its breath freshening capabilities not because it doesn't contain SLS.
So there you have it. I would welcome any discussion or questions.