When I said detergents are in everything these days, I guess I didn’t know the half of it.

The Whole Foods web site lists “ingredients that are commonly found as inactive ingredients, or excipients, in dietary supplements.”  Sodium lauryl sulfate is listed as an “emulsifier; also used to aid in the making of tablets.”  It’s also listed as GRAS (generally recognized as safe, though a lot of dermatology patients would beg to differ).  Does this mean supplements, especially tablets, are a potentially hidden source of detergents?

What about over-the-counter and prescription medications?  I just found SLS listed in the “inert ingredients” of Doryx, an important delayed-release formulation of doxycycline.  Here I’m guessing the SLS is necessary for the time release.  If so, the benefits might outweigh the consequences.  Tetracyclines aren’t generally given to children anyway.

But if the posters to this Wisegeek.com article are correct, SLS is in such common medications as aspirin, ibuprofen, and Zyrtec, which are given to children.   Poster #5 found SLS in one generic formulation of Zyrtec but not another.  It probably pays to ask the pharmacist for a detailed manufacturer’s insert to identify inert ingredients of prescribed medications.  Taking the medication prescribed by one’s doctor is the more important consideration, but often there is a choice of formulations, and different pharmacies often have very different options.

Check out this EPA document:   “Sodium lauryl sulfate is used as a flea and tick repellant in one registered pesticide product — a flea and tick shampoo for cats and dogs.  Sodium lauryl sulfate also is a widely used component of many non-pesticidal consumer products currently marketed in the United States, including shampoos and fruit juices.”

Fruit juices?! I had assumed the eczema from some processed juices had been from washing the fruit in food-grade detergents.  Now I wonder about SLS as an additive!

The document above is from 1993, so the assessment may have changed since then (though I doubt it).

It continues:

“Sodium lauryl sulfate is a detergent-like substance that employs a non-toxic mode of action in controlling fleas and ticks on household pets. The potential for dermal and/or inhalation exposure exists to people applying the registered pet shampoo product. However, this exposure is not considered significant and does not create a health risk concern. Published reports suggest that sodium lauryl sulfate has low acute mammalian toxicity and no known chronic effects. EPA has no reports of adverse effects resulting from its use. Both exposure and health risks to people using the product are expected to be low.

EPA also believes that since the pesticide is used only on pets, negligible exposure to the environment and to nontarget organisms will result. The Agency concludes that the registered product and use of sodium lauryl sulfate should not result in unreasonable adverse effects to human health or the environment.

Yet one more source of detergent for Solveeczema users to watch out for — reading the labels of flea collars, too.  However, since the collars are used externally, I wonder if they even have to list the “inert” ingredients?  If pet owners had problems, would it seem like an allergy to the pet?

On that score, here’s an interesting paper from a veterinary journal:  Influence of inert ingredients in pesticide formulations on dermal absorption of carbaryl by RE Baynes and JE Riviere (PMID 9492931), Feb 1998.

“The SLS also enhanced [the carbamate insecticide] absorption, especially at low solvent concentrations.”  and in conclusion , “Inert ingredients can modulate percutaneous absorption of toxicologically important pesticides…”

And lastly, a paper from Environmental Health Perspectives from 2006 (PMID 17185266):   “By statute or regulation in the United States and elsewhere, pesticide ingredients are divided into two categories: active and inert (sometimes referred to as other ingredients, adjuvants, or coformulants). Despite their name, inert ingredients may be biologically or chemically active and are labeled inert only because of their function in the formulated product. Most of the tests required to register a pesticide are performed with the active ingredient alone, not the full pesticide formulation. Inert ingredients are generally not identified on product labels and are often claimed to be confidential business information.”  (emphases mine)