Warning: Chlorinated paraffins in immersion blenders (stick blenders)

Since these are popular for making fat bombs, emulsified drinks and many things we would be interested in for a high-fat diet, I was alarmed when I discovered this:

http://www.thedoctorwillseeyounow.com/content/public_health/art4511.html

I haven't looked in detail at where exactly the chemical leaches from, but maybe there is a way to know based on construction whether a blender will have food-contacting parts that contain it.

The scientific study perhaps is not the most rigorous.

"Due to the analytical difficulties associated with quantification of CPs no actual amounts or concentrations are presented. Further, the present study does not include any study relating potential decreasing leakage of CP with usage time of the hand blenders."
_http://www.su.se/polopoly_fs/1.208355.1414491286!/menu/standard/file/Report%20on%20hand%20blenders%20leaking%20CPs%20%28Eng%29.pdf
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Interesting that you mention this, because we have noticed a dark coloured liquid leaking from the base that smells really chemically. It usually happens when we use it for a long time and it begins to overheat. We decided to change to a better quality metal one to see if anything changes

Just being metal doesn't guarantee that it is free of chlorinated paraffins. I'm not sure if the risk of contamination has anything to do with the "quality" of the blender either. The results seem to indicate it depends more on the country of manufacture than anything. Some of the safest tools are also very cheaply built. Hopefully more information will come out eventually.

Here is a useful document to explain what Chlorinated Paraffins are used for and why they might end up in a hand blender.

http://www.midbrook.com/assets/PDFs/WhitePapers/Cleaning-Chlorinated-Paraffins.pdf

The short of it is that Chlorinated Paraffins are a type of thick wax which is heavier than water and used to lubricate metalworking tools like cutters, stamps, grinders, etc. I think it is something like a cutting fluid that is applied directly to the metal where it is to be cut, or on the tool doing the cutting. It is sometimes added to lubricants such as motor oil because it can reduce friction between moving parts. The qualities that make them so helpful in making clean cuts also make them very hard to clean off. Guidelines are given as to how to clean them off. This would explain why the contamination presence seems to have little to do with quality or construction of the blender - the factories may each have varying levels of success in cleaning.

One very telling comment is that if the high-PSI sprayers and chemicals don't work, then the only solution is to "rub it off with a cloth by hand".

So I see two uses of Chlorinated Paraffins in immersion blenders: for cutting the blade and other metal parts, and for lubricating the blade seal. They can be used in other areas of the blender such as the motor but if so should not contaminate the blade section.

The commentary on their presence in immersion blenders seems to assume they are used for stamping and cutting the metal parts, not as a lubricant. If this is so, then the levels should diminish over time and the best solution may simply be to clean the food-contacting parts thoroughly by hand.

Some immersion blenders have very rough "brushed" finish which increases the surface area of the steel and would seem to impose more contamination risk and cleaning difficulty.