Polyaminopropyl Biguanide

Andi Asks:

Hi Steph,

Sorry to bug you, but I was wondering if you could tell me about Polyaminopropyl Biguanide. I've heard that is is a safe preservative, but I'm assuming it's synthetic and not really that healthy. Thanks for the help and take care!

Answer:

Thanks for your question!  I've just posted my analysis of Polyaminopropyl Biguanide to the blog.  Check it out: http://chemicaloftheday.squarespace.com/todays-chemical/2009/9/5/polyaminopropyl-biguanide.html

Sodium Bicarbonate

Arlene Asks:

How do you feel about sodium bicarbonate in deodorant and toothpaste?

Answer:

Sodium bicarbonate is just plain old baking soda.  Some people find it irritating to their skin when used straight on their skin, or in a higher concentration, but other than that, you're totally safe with it in deodorant and toothpaste!   

Sodium Cocoyl Glutamate & MSM

Q.  My question is actually in regards to 2 of the ingredients...Sodium Cocoyl Glutamate and Methylsulfonylmethane (MSM). Any ideas? Thanks!

-Alicia

A.  That's a great question.  MSM is not a dangerous ingredient; in fact many people take is as a supplement to improve joint health.  Sodium Cocoyl Glutamate scores a 0 in the Cosmetics Database, but I'm hesitant to give it a passing grade just yet.  It scores low just because it's a new chemical that hasn't been studied much.  It's derived from glutamaic acid, which is very similair to MSG.  Even though on skin it's not going to have the same effect as MSG, but I'm holding out to see if there are more studies done before I give it my stamp of approval.  There has only been one published study done on the ingredient.  They found that a blend of Sodium Laureth Sulfate and Sodium Cocoyl Glutamate was more gentle on skin than a blend of Sodium Laureth Sulfate and Coco Betaine.  So, it looks like it could be a safer detergent alternative, but it's still a synthetic ingredient.

Citric Acid

Q. I have noticed that citric acid is in quite a few "natural" products. From shampoo to bar soap. Is it bad for you? It always seems to appear at the bottom of the ingredient list....so I am guessing that there are minimal amounts of it. Just curious....Thanks!!

A.  Citric acid is a weak acid present in all citrus fruits; it's what gives citrus that nice sour zing!  If it were dangerous, we couldn't eat oranges!  As a cosmetic ingredient, it depends on how it's used.  Citric acid at full strength can burn skin and eyes (you know the phrase...lemon juice in a paper cut), that's why it gets a little higher risk score in the Cosmetics Database.  But used in shampoos and soaps, it's a minimal amount that's used just to "balance" the pH.  Soap is naturally alkaline, so some companies add citric acid to lower the pH so it matches skin's natural pH a little more.  However, in this case, there's no leftover citric acid because it's combined with the alkali in the soap.   When you combine an acid and an alkali, all you get is water and a salt.  So, really it's not even present in the soap.  Shampoos, if they're detergent based, are different because the citric acid is used to make the shampoo actually acidic.  However, it's not really going to be acidic enough to worry about, and having citric acid in it is not going to pose any health risk.  The bottom line: you probably don't want to put citric acid on your skin at full strength as it stings a bit (kind of like vinegar) but as used in shampoos and soaps, it's a safe and natural ingredient.

Grapefruit Seed Extract (GSE)

Q. ---grapefruit seed extract. My favorite hair conditioner (Nurture My Body) which is also too expensive for me to buy anymore, contains this ingredient as a preservative. Is it toxic? Or simply likely to be contaminated with toxins?

Philip

A. I've just added it as my "Chemical of the Day" here.  Check it out!