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Old 10-19-2003, 11:29 AM
Faith Faith is offline
Join Date: Nov 2002
Posts: 13
Does Sulphate contain sulfa

I am trying to find out about a product cleanser with Sodium Lauryl Sulfate. I am allergic to sulfa, does anyone know if it would be okay to use a cleanser for your face that contains Sodium Lauryl Sulfate?

Old 10-19-2003, 11:53 AM
Squink Squink is offline
Join Date: Oct 2000
Location: Yes
Posts: 20,327
Sodium Lauryl Sulfate, also called sodium laureth sulfate, or SDS is the major ingredient in most shampoos. If you were allergic to it, you would already know. SDS has a completely different chemical structure from the sulfa drugs, so an allergy to one is not likely to translate into an allergy to the other.
Old 10-19-2003, 12:16 PM
MasterChief MasterChief is offline
Join Date: Oct 2003
Posts: 40
I am working on my thesis in Chemistry.

Sulfa drugs have nothing to do with SDS, rest assured.
Old 10-19-2003, 01:01 PM
Roches Roches is offline
Join Date: Aug 2003
Posts: 987
Sodium lauryl sulfate is also known as sodium dodecyl sulfate; 'lauric acid' is the old name for dodecanoic acid (CH3-(CH2)10-COOH). Sodium laureth sulfate is not the same; it's an ether of sodium lauryl sulfate with poly(ethylene glycol). It's used in 'high foaming' detergents and shampoos.

Sodium lauryl sulfate has been used for some time in detergents, and is quite harmless. It's more effective than ordinary soap -- the sodium salt of a fatty acid, e.g. sodium laurate -- because the 'sulfate' part makes the polar end (the one that attracts water) more polar. Thus, SDS isn't affected by hard water as much as soap, and is generally better at cleaning things. A few years ago, there was an urban legend that SDS was carcinogenic.

As Squink explained, allergy to sulfa drugs (sulfonamides) is unrelated to allergy to SDS. You'd certainly know if you were allergic to SDS -- it's everywhere. True allergy to SDS is probably extremely rare -- if it exists at all -- though some people with very sensitive skin might find that it irritates them, especially their face. If that's the case, SDS-free facial cleansers are available and generally say they're SDS-free very clearly on the label.
Old 10-19-2003, 01:14 PM
Squink Squink is offline
Join Date: Oct 2000
Location: Yes
Posts: 20,327
Sodium laureth sulfate is not the same; it's an ether...
Oh, CRAP I knew that. Don't know where my head is this morning. Probably OD'd on too much shampoo.


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