Inanna - without attempting to nitpick, or derail the thread from its intended purposes - I would genuinely be interested to see incontrovertible evidence that SLES (sodium laureth sulphate, not SLS, sodium lauryl sulphate - they are not the same) is a known carcinogen, as it is something that the available evidence does not support. (OK, anyone here who doesn't want to hear a whole bunch of science geekery can skip most of this post). But there is a point to derailing... I'll get to that later.

First, I should point out that I don't use products with SLS because it is a known irritant. I also use organic and synthetic free biodegradable products and only bi-carb and vinegar when cleaning. So I am not an advocate for synthetic use. If anything I am the opposite.

Secondly, I will not deny that SLS and SLES are both known irritants. But they are not recognised carcinogens by any agency, including all regulatory and cancer advisory bodies in Australia, and the FDA, EPA, CTFA, and the US College of Toxicology in the US.

So why the perception that SLS is a carcinogen?

Two reasons:
- Because of a widely spread internet rumour that SLS (as opposed to SLES) is a carcinogen. This arose because SLS is routinely used to solubilize chemicals used in carcinogen tests prior to injecting them into test animals. The solubilizer was mistook for the active ingredient.

- Secondly, because of a confusion with SLES.
Unlike SLS, SLES is synthesised by ethoxylation, and as a result can contain trace amounts of the 1,4-Dioxane (which can be and usually is removed during production, however, this is not mandated). This is listed as a probable human carcinogen by the EPA prompted studies on rats which have demonstrated that carcinoma rates increased with high doses of 1,4-Dioxane administered orally (in drinking water).

However, studies testing inhalation showed no increase in carcinoma amongst the test population, a result which correlates with epidemiology studies on workers exposed to high amounts of inhaled 1,4-Dioxane (cancer rates were on par with that of the general population). Most relevant to the cosmetic industry, tests on mice with skin absorption showed no increase in cancer rates where high doses of 1,4-Dioxane (well in excess of those found in products containing SLES) was used alone. (In combination with another substance, which is not used in cosmetic or domestic preparations but in industrial ones, it was found to be a carcinogenic promoter). However, it is noted by the FDA in their advisory notice that most of the dioxane in preparations applied to the skin evaporates into the environment and is not available for absorption.

So to recap, the evidence is:
- 1,4-Dioxane is a probable human carcinogen. But, the evidence suggests that it is carcinogenic when consumed orally (via drinking water) in high doses, with rates of cancer amongst subjects exposed by inhalation or skin exposure to doses much higher than what is found in human skin being consistent with a control population.
- 1,4-Dioxane can be found in trace amounts in SLES, but can be, and often is removed during the synthesising procedure. As it is not mandated that this is done, it is unknown exactly what percentage of raw SLES has been dioxane scrubbed.
- SLES and SLS are both listed as known irritants. There is no evidence to suggest that they are carcinogens, and the amounts of 1,4-Dioxane found in samples of cosmetic products containing SLES have been sufficient only to prompt further monitoring, they have been well under the amounts advised the EPA as being safe for oral consumption.

So why have I gone on this rather extensive ramble? Not to specifically debunk what you are saying, and I do get your point that cumulative effect of substances can be damaging, as can exposure to a wide variety of substances in combination.

And I also agree that it is absolutely critical to explore all avenues of research in the attempt to discover the cause of SIDS (amongst other things). And I will concede that sometimes respectable or mainstream research organisations or regulatory bodies will cherry pick data without qualm in order to support a political agenda (the AMA's recent exploits are a great example of that), or at the very least follow only conservative avenues of research.

But my concern is that like the SLS debate, or the recent claim that stillbirth can be partially attributed to fluoridated water but is unsupported by any of the stillbirth statistics in Australia (QLD, which has up until this year had a 4% uptake of fluoridated water compared to up to 100% in other states, yet has an identical if not higher rate of stillbirth), is that this research sounds great but is unable to be substantiated. Some of the claims that JellyBean has quoted (in the article from Dr Mercola's site) seem to be similar examples of cherry-picking, and the results of such research have not been able to be replicated at this point. I don't have any issue with the claims themselves, just their veracity. As an example, the work and qualifications of Dr Viera Scheibner (whose PhD was actually in Geology, not in any health sciences) has been almost universally debunked in peer review, and her bias as an anti-vaccination advocate is well known to the point that any claim that she makes that she was not initially looking for a link to vaccination as a cause for SIDS is dubious at best. Any article using the claims of such a scientist as a lynchpin of its argument holds no credibility for me.

So it is not possible to claim them as fact when most of this research is not supported either by peer review, by supporting research or by statistics (and I gave examples of these in my previous post). If these claims can be supported, then great. If they were presented as possible theories that were worthy of further research - that's great too. But I think that the way that this information has been presented sounds like conspiracy theory presented as fact rather than science; once it is presented as legitimate science I will take it much more seriously.

My issue with these claims have nothing to do with mainstream conditioning (which, if you knew me you'd agree is pretty funny as I am pretty close to the extreme end of raving anarchist sceptic), but with the veracity of the science behind them. Just like my issue with some of the claims behind SLES. Doesn't mean that they're not worthy of further investigation, but also doesn't mean that they will turn out to be the correct answer either.