I Can Has Science Hair Straightener?

My apologies, I really do not want to turn this into a Brazilian Blowout Blog.  However, I am super swamped this week and am writing on borrowed time, and Brazilian Blowout keeps falling into my lap.  The last week and a half, I’ve been talking about the formaldehyde/methylene glycol controversy surrounding the hair product Brazilian Blowout.

Doug Schoon, the guy confronting OSHA on their use of “methylene glycol” as a synonym for “formaldehyde”, wrote a comment on my last post.  He made one correction to my post: he is not representing Brazilian Blowout per se (not sure where his funding comes from, he didn’t specify).   For the rest of his comment and my previous post, see here. The following is my response:

Dear Mr. Schoon,

I appreciate your concern for safety in the cosmetics industry, especially if you are not being funded by Brazilian Blowout or other companies.  However, I think you may be going down rabbit trails worrying about the semantics of formaldehyde vs. methylene glycol.

To begin with, you expressed concern that I was propagating misunderstandings by claiming that methylene glycol and formaldehyde are in a 3 to 1 ratio.  However, I think if you’ll read what I wrote, you’ll see that the 3 to 1 ratio was used to describe an example system between hypothetical “yellow and green molecules” to explain the concept of equilibrium.  I clearly state in the text and in the next graphic that the methylene glycol:formaldehyde ratio is >1000:1. (Actually, one K_eq I’ve seen published is 1.82 x 10^3, which means there are 1820 molecules of methylene glycol for every one of formaldehyde.)

But I think you’re missing the point here.  It does not matter that only 0.05% of the molecules exist as formaldehyde proper in solution. Given sufficient flesh-exposure time, or if water is removed with a hair dryer, 100% of the methylene glycol could convert into formaldehyde. (According to Le Châtelier’s, and I’m rounding 99.999-repeating to 100; see previous post.)  As far as I know, there is no way to prevent this reactivity of methylene glycol.  I believe this is why OSHA considers the two compounds to be the same.

Next, in your letter to OSHA, you bring up the existence of two different CAS numbers for formaldehyde and methylene glycol.  However, I think that is irrelevant.  For example, sodium chloride (table salt) and sodium bicarbonate (baking soda) have two different CAS numbers.  Yet for the purposes of nutritional information, the amounts of both are summed up to tell you “sodium content.”  (And nobody gets upset about the technicality of the word “sodium” there, even though to be completely correct we should specify that it’s sodium ion.  Any food with non-cationic sodium would be a fire hazard. And there’s no such thing as “sodium ion” by itself anyway.)

Let’s face it Mr. Schoon, methylene glycol is going to be formaldehyde if it comes in contact with your body.  Now if you want to really help out the hair-straightening companies, figure out a way that formaldehye/methylene glycol can be used with as minimal risk as possible.

I would be happy to discuss this further with you in the future.  I feel reasonably confident about my understanding of chemistry principles, but I have no experience with the cosmetics industry and I’ve had only minimal exposure to the ins and outs of safety regulations.  So this is all rather interesting to me, despite our difference of opinions.

Thanks for explaining your side a bit,

Sharon
(M.S. Chemistry… T – 1.5 years to PhD (fingers crossed))