Formaldehyde is where you least expect it. If you ask most people, their first experience with formaldehyde arose in high school biology. Perhaps you recall biological specimens ominously afloat in jars of stinky liquid. (Formaldehyde is actually a gas, not a liquid, but because gasses are so inconvenient to deal with what with their flying around a room uncooperatively, formaldehyde is usually dissolved in water to make it more compliant—and if it is around 10% to 30% this mixture is then called formalin.) Or if you are like me, you associate formaldehyde with the smell of embalming fluid if you have spent any time hanging around cadavers (sometimes I teach anatomy).
Now what surprised me in researching formaldehyde was just how many modern products contain or release it, from cosmetics to building materials and even some common, chemically-treated forms of cotton, wool, and silk—what I'd presumed was "natural" fabric. The word "formaldehyde" does not appear in the ingredients list of any cosmetic that I am aware of, and I'd be startled to find it there. However, many lotions, hair products, deodorants, and other cosmetics contain preservative molecules that react to become formaldehyde, known as formaldehyde releasers. I have a list of these releasers below. (You could always copy the list to bring it to the store with you the next time you go shopping, to squint endlessly at ingredient lists to find them, as I now do. Think of it as a sort of un-treasure hunt.)
What you don't know can hurt you.
Exposing yourself and your family to formaldehyde in apparently benign consumer products is worth thinking about. This is because of excellent, what scientists like to call rigorous, evidence that formaldehyde causes, at best, contact dermatitis, allergic reactions, and rashes, and at worst, cancers like leukemia. You can bore yourself, as I have, reading lots of published, peer-reviewed, epidemiological and laboratory studies in reputable science journals to confirm there's sound evidence for this. Now, I don't think we need to panic, but it does make sense to educate ourselves and to limit our exposure to formaldehyde. That's just smart. We can also put pressure on companies to please sell us healthier alternatives, even if we (meaning me actually) are scared that some of them might snipe back with accusations that we are anti-business or that we are unpatriotic.
The real reason why a molecule is bad for you—it's never about where it comes from.
First of all, if you look around on the Internet at all the various sources of information and misinformation about whether or not formaldehyde is actually that bad, you could easily get confused. This is because we habitually judge molecules based on where we find them, rather than what they do, and my point is that this is a bad habit. This confuses everyone! People are always asking, "where did you get that molecule?" as if the original habitat of a molecule haunted it throughout its existence, and provoked it into good or bad behavior. Formaldehyde is found in cells, in plants, in our bodies, even in floating about in outer space, plus we can make it in a lab if we want to. Does this make it good or bad?
All formaldehyde molecules are identical, by the way. All formaldehyde molecules have one carbon that is attached to two hydrogens, and that one carbon is also attached to an oxygen by something called a double bond. These four atoms, when attached in this manner, are the whole thing. It is a tiny, inanimate object, without a memory or a motive, and, regardless of its origin, all formaldehyde molecules are the same and have this structure:
Stay with me here, I really do have a point with all this boring if-it-has-four-atoms-connected-in-this-exact-structure-it's-formaldehyde chemistry lecture.
It came from my body so it can't hurt you...?
Now, part of my researching formaldehyde and other molecules inevitably gets dragged down by running into a sort of disinformation campaign. It is one that tries to convince you that a molecule isn't really that bad because "it's found in your own body" or that it is "found in plants". Or you'll hear that it is bad because it was made in a nasty lab by nasty humans (even though humans are only extra-smart animals and thus a frighteningly integral part of nature, too.) What makes the Origination-Determines-Goodness argument even more confusing is that molecules found "in nature" are in every way identical to what we make in a lab if we want them to be. All you have to do is have the same connections of the same atoms, and it is the same molecule! A lab-made molecule behaves the same way as one extracted from the environment in every conceivable test as long as this is true. This has been proven unambiguously, repeatedly, since the first organic molecule was synthesized in 1828. (This was the molecule urea, which is found in your own body—it's in urine.)
People get very emotional about where a molecule comes from, too, and that makes me scared to recount the facts, sometimes. At one talk I even had a passionate audience member drag me aside afterwards to try to convince me that a person's intention of making a molecule, either for profit (bad) or to heal (good) affects the molecule's goodness. This notion sounds too mystical for me to imagine how you could go about scientifically testing it. Lots of money is at stake in selling, promoting or demoting and demonizing various molecules based on where the molecule comes from. But I feel I must address this repeatedly simply because it comes up repeatedly: What is most instructive to ignore where we find a molecule and just see what it does.
For example, the oil and chemical industry billionaire Koch brothers, whose companies incidentally profit from selling products that release formaldehyde, employ lobbyists who petition the EPA with reassuring statements like "formaldehyde is found in all organic life forms" (so are there other types of life forms? If so, please tell me about them!), and that "it does not accumulate in the environment".
But as you will soon see, formaldehyde doesn't accumulate in the environment because it is so unstable, it transforms into something else upon reacting with your tissues before it has time to do anything else like accumulate. Koch Industries also employs lawyers to complain about the un-American and anti-business-minded nature of any writer who quibbles with their pro-formaldehyde stance so maybe I had better watch myself here and keep to the topic.
This argument—that something isn't that bad because it is found in your own body—always makes me want to pound my head on my laptop. Our bodies also naturally make poo. And although E. coli is in my own body, and I will not suggest it is benign or that we should all bathe in it. Enough said.
Unfortunately we seem to be stuck in an old fashioned mind-set of judging the worth of a molecule by where it comes from, which is interesting, but rarely helpful. Nature makes both rash-inducing irritants and nourishing vitamins in the same plant. We know that we ought to judge people by how they behave, not where they are from, otherwise we are bigots and not very smart. We should do the same for molecules. Good questions to ask a molecule are, "Are you too stable or too unstable? Do you impersonate other key biomolecules? Do you play well with other molecules or do you destroy them randomly? How do you behave in children, animals, men, women, and the environment?"
How to think like a toxicologist: a molecule's structure and stability is key.
The toxicity of a molecule really does not have anything to do with where it comes from, even though some sources, like snake venom, are more reliable sources of toxins than others. The toxicity of a molecule often has to do with its structural stability, which is dependent on the arrangement of its atoms. Some molecular structures are more stable than others. Why is stability important?
If you live next to an unstable neighbor, you might worry, for example. An unstable neighbor could be is more likely to play with explosives in their garage, or put weird things in your garden, and it does not matter what country they come from. Stability is not the only reason for a molecule's actions—sometimes molecules engage in identity theft, so to speak, impersonating other similar-looking molecules in your body, which can actually be either good or bad depending on the situation. But toxicity always has to do with a molecule's appearance, it's structure, not where it is from. That's why I was going on about how "one carbon's attached to an oxygen and two hydrogens" in formaldehyde. It's important.
A molecule's bonds should be neither too stable nor too unstable.
Molecules have to have the right sort of stability to be benign. If they are too stable, organisms can not break them down easily, and they persist in our neighborhoods. This is only a problem if they also happen to be toxic, like PCBs, which have a structure similar to steroid hormones, and impersonate them, which ends up causing serious problems in a cell. So, it's good for molecules to be able to neatly break down and get recycled by cells of some sort of organism. However, some unstable molecules break down in a messy way that causes damage to other molecules near them. Formaldehyde is one of these, breaking down in a messy way, that like an explosion, hurts other innocent bystander molecules.
What determines stability has to do with what atoms are attached, and in what way. Some sorts of connections between atoms are more stable than others, and chemists learn how to recognize patterns that are either stable or unstable based on some simple rules. (If you can ever get through the grueling process of your first chemistry class, which I think is honestly the hardest chemistry class anyone can take, organic chemistry is next, which teaches you to recognize these simple patterns, and it is so much easier and more fun!)
The sad story of formaldehyde's naked, sticky carbon (warning: chemistry ahead. You can skip this section if you are in a hurry, but you are smart enough to understand it!)
The real reason why formaldehyde is bad for you is because the molecule is unstable, just like a two-legged chair is unstable. It doesn't matter where you find the two-legged chair, whether you buy it from a factory or make it by hand or if you happen to find it on Mars. If the chair has only two legs it will fall over when you sit in it.
There are two reasons why formaldehyde is unstable:
1) Its slightly positively charged carbon makes the carbon chemically "sticky", and
2) its carbon is more exposed than carbons in most other molecules.
In more detail:
1) Formaldehyde is unstable because the single carbon atom in it has what chemists call a strong "partial positive" charge. This isn't as positive as +1, but it isn't zero, either—you could imagine it as something like +0.5 but it's actual value is less important than the fact that it is not zero. For some reason (we actually don't know why!) nature predictably loves charges to be as close to zero as possible. We never see charges as high as +25 just hanging around in any object, for example. That would be very unstable and nature would find a way to mix that ridiculously positive charge up with any nearby negative charges to neutralize it, or nature would spread that large charge out over large area to make it the charge less localized and dense in one small region. We may not know why nature loves charges to be zero, but we can make fantastically good predictions about the behavior of charged things knowing that's the case.
That being said, some atoms comfortably tolerate small positive or negative charges and may even "prefer" (be more stable) to have charges on them (this is based on esoteric geometrical things like the atom's size and the distance from their positively charged centers to their negatively charged outer electron clouds.) But carbon just isn't one of those atoms that tolerates even a fractional charge.
The reason why this carbon has this strong partial positive charge in the first place has to do with its double bond to oxygen. Oxygen always pulls negative charge away from any carbon that it is directly bonded to, making the carbon less negative and therefore more positive (and if you want to know why oxygen does this, I'd have to tell you about something called electronegativity and risk losing the focus of this article.) In my mind this partial positive charge on carbon makes the carbon reactive or "sticky".
2) Now, not only is this carbon "unhappily" partially positive, but unlike most carbons in other compounds, it doesn't have much near it to physically block the approach of something negative that could neutralize its unstable charge. Most carbons in other molecules have bigger, bulkier atoms attached to them, like other carbons. Not only is formaldehyde's carbon sticky, but it is kind of naked, too. You can't see this in the structure above, but hydrogen atoms are the smallest of all the atoms, and the two teeny tiny hydrogen atoms bonded to the carbon are not big enough to physically shield the carbon from the interest of something that it could bump into and could bond with it.
The stability of massive objects like two-legged chairs is dependent mainly on the Law of Gravity. Since molecules don't weigh much, their stability is instead dominated by another natural Law: Nature's tendency to make charges as close to zero as possible, otherwise known as the Electrostatic Law. This second law, in my mind, explains almost all chemical phenomena, which is saying a lot.
Chemistry part over: now the biology. Formaldehyde breaks apart, crosslinking proteins.
There is a reason why formaldehyde preserves tissues. Remember that formaldehyde's unstable carbon "wants" to be stabilized by something negative? In biological tissues, the negative thing it will most likely to encounter is something called an amine. An amine is just a particular pattern of atoms commonly found around a nitrogen atom, and you can depend on that nitrogen to have negatively charged particles called electrons hanging out on it because that is always part of how an amine's structure is defined. Amines are abundant in living things, as you can reliably find them in proteins and DNA.
So, formaldehyde reacts with both proteins and DNA. More precisely, formaldehyde's carbon yanks on the amine's electrons and turns them into a strong bond, which helps carbon have a charge closer to zero. The remnants of the formaldehyde molecule remains unstable, so continues to self-destruct and eventually welds itself onto a second nearby amine. This bonding is the real problem.
Formaldehyde ties together proteins to other proteins, and occasionally to DNA too. This action is termed crosslinking. Crosslinking renders the fraction of vulnerable proteins and DNA that the formaldehyde was in direct physical contact with permanently dysfunctional or useless. If you were a protein, imagine you get some gigantic object permanently stuck to your hand. That would make you less able to perform your regular activities too, right?
Not only does this crosslinking stiffen and toughen the tissue and make it less likely to break down, it also makes too tough for bacteria that would like to eat it and decompose it, and formaldehyde tends to kill those bacteria, anyway, because it does the same thing to their proteins. That's why formaldehyde preserves tissues—nothing left alive can eat much of what is left of the tissues. The residual sugars, water, and small molecules remain encased in a gooey matrix of toughened, crosslinked proteins.
This crosslinking is all fine and good for tissue that's already dead, but what about having this activity going on in our own living tissue? Dysfunctional and useless proteins and DNA in our bodies? Should we panic about that? It depends.
Now, it isn't necessarily the end of the world if some of your protein or even your DNA is mechanically abused this way—it happens every day in the wear and tear of normal aging and we have evolved wonderful enzymes that zip around, repairing or breaking down and recycling our damaged molecules. (Yes, cells recycle. How about that! I am always reminding my students that cells have survived on earth for billions of years, so if we have any smarts we should copy this obviously brilliant energy strategy. Even our grandparents knew how to re-use things. But I digress...) So, our bodies can repair molecular damage to some extent. However, not all DNA damage is the same--some is harder to repair. Crosslinking is hard to repair.
Adducts Cause Cancer
This cross-linking form of damage involves the formation type of bond (called covalent) that is especially tough to break. The unwelcome addition to our newly appendaged molecule is called an adduct (pronounced ADD-uct). Literally an adduct gets stuck to valuable molecules and it won't come off, so those molecules malfunction. (Well, to be technically correct, the formaldehyde reaction is considered reversible and you could break the adduct off if you want to heat it to 203 F (95 C). But because it is insane to burn yourself this is not a practical consideration unless you are talking about doing that reversal in a test tube.)
My pulse quickens when I read about molecules forming adducts to DNA because that is usually bad news and the first thing I think is, "oh, oh, that could be carcinogenic". Adduct-forming molecules often are. (In researching the herb valerian for my book Herbs Demystified, for example, I was concerned to learn that this plant contained a molecule with an unstable bond called an epoxide. Epoxides form adducts and some are carcinogenic. However, there does not appear to be an association of valerian consumers with cancer that is statistically obvious, perhaps because valerian's epoxides may degrade too quickly to cause harm.)
Examples of known carcinogen molecules that form adducts are found in tobacco smoke, burned meat (polyaromatic hydrocarbons and nitrosamines), fungal toxins (aflatoxin), certain pesticides (lindane) and even (weakly) estrogen. Even some simple elements form adducts, too, like mercury, lead, and arsenic. Some are more effective at forming adducts than others, and although our body can repair some adduct damage, obviously less exposure to adduct-formers is a good idea. The more you expose yourself, the more you roll the dice to get a cancerous cell. Why does this cause cancer, though?
Typically one or two permanently damaged DNA molecules doesn't cause cancer, but the more you damage, the greater the risk of cancer. DNA provides instructions for making a protein, so if you mess up these instructions you get eventually get a dysfunctional protein. What happens is that eventually you get a protein that malfunctions in that it fails to turn cell division off (the cell's brake gets stuck in the off position), or it malfunctions in that it continuously turns cell division on (the cell's accelerator gets stuck in the on position.) Either way, you get a continuously dividing cell, which turns into a mass of dividing cells called a tumor. And guess what! Formaldehyde is officially considered carcinogenic. It is most associated with "blood cancers", that is, cancers of white blood cells like leukemia. Lots of unhappy lab animals have proved that. People who work with formaldehyde in industry are statistically more likely to get leukemia, too.
If you just expose your skin to it or breathe it in (remember, it's really a gas) it will do some limited crosslinking of proteins in your skin and respiratory tract. So it's not surprising that it is well known to cause contact dermatitis, rashes, and irritation. Since this attracts the attention of your immune defense system, it is common to develop an allergy to it.
Some natural fabrics are more natural than others.
I'd always felt a bit righteous buying "100% cotton" but now I've reconsidered how I purchase my family's knickers. One of my dear friends, fiber artist and fashion designer Peter Ciesla of Bazyli Studios in Baileys Harbor, Wisconsin, recently complained that after years of professional sewing, he will no longer work with certain fabrics because of painful rashes on his hands. From now on, he said, he was doing only organic fabrics, or vintage recycled ones. "What sorts of fabrics have been hurting you?" I asked, my inner toxicologist anticipating a list of weird new synthetics. I was very surprised when he said his problem was with certain cottons, silks, and wools. What?
Convenience vs. rashes, it's up to you.
It turns out that, in the 50's, our desire to avoid wrinkly fabrics inspired the creation of chemical solutions that crosslink our textiles into a more compliant state. Originally formaldehyde was used. Now formaldehyde is still used, though there is less of it in modern commercial resins, with some companies like BASF even promoting an "eco" version resin with lower formaldehyde called "eco fixapret". Yet anything that is "permanent press", "easy wear", or "wash and wear" is likely to release some irritating substance which, if not formaldehyde, is related to it structurally, and will work in the same irritating manner.
Are you allergic to your clothes?
Formaldehyde and its releasers are the most common cause of contact dermatitis. This is according to the riveting textbook Practical Contact Dermatitis (1995, Guin), which has a whole chapter devoted to formaldehyde! If you get a rash where your clothing contacts your body closely, this text proposes it's likely formaldehyde is to blame. Do you handle a lot of clothing in your profession? My poor friend Peter's textile version of formaldehyde allergy arose after years of fingering formaldehyde releasing fabrics as a professional fabric artist. Also, this dermatology text advises if you get rashes where you sweat, since damp fabric clings more to your skin, this text suggests formaldehyde in the fabric is the culprit. Solution: tolerate wrinkly non-permanent press clothes or buy an iron. Remember those things?
Permanent press hair is now available and is causing the same problems.
Sophie Uliano, author of the fabulous reference Gorgeously Green, suggested I investigate the use of formaldehyde in the latest trend, a hair-straightening procedure, memorably trademarked a "Brazilian Blowout". It's also called keratin hair straightening, and is apparently immensely popular for women who just want their hair straight. Even though it only lasts about three months and costs a pretty penny, some women who can afford it love it, and have it done regularly. However, there are also plenty of women complaining about how it has caused rashes and even serious breathing problems following the procedure.
Intimidated by beauty salons, I'll confess I shy away from them, trimming my own hair the low tech dorky way (admittedly badly) with scissors and a mirror. So I knew nothing about this procedure, of course. And when I told my husband that I needed to learn about Brazilian Blowouts he perked right up and waggled his eyebrows suggestively at me. He didn't know what it was, either. We are both dorks.
I was in luck because our peninsula is now abuzz about a brand new ecological beauty salon opening in Egg Harbor, Wisconsin, Spa Verde, conveniently next to our local health food store, Greens N' Grains. And I just happened to know the lovely stylist managing the salon, Andria Nikoupolis-Weliky, so I thought she'd be the perfect person to ask about this procedure.
Andria said she felt compelled to open the salon because she felt so worried about the health risks from exposure to common salon products that she had herself used for years. I have no experience with nail products, because I play the harp and trim my nails down to oblivion to prevent unpleasant string clicks. Yet I do have friends with beautified nails that continually irritate them. Andria informed me that several brands of nail polish are particularly problematic for women. Andria said her salon uses alternative polishes that don't have formaldehyde or their releasers. So, healthier options for nails are available.
I asked Andria what she would do if a woman came into her salon and asked for this Brazilian Blowout, or keratin straightening, or whatever you want to call it. She said she would partly counsel the woman to find out what she really wants. It would be a lot easier to start with someone who was comfortable with whatever hair type they already have, she confided. She would encourage the person to learn to be comfortable with who they are and the hair they were born with. But if this sort of personal counseling failed, and a curly-haired woman insisted on having straight hair, Andria would be honest with them and tell them their ecological options. She'd use traditional and non-toxic methods like a flattening iron and non-toxic hair care products—which would need to be repeated after every shampoo.
So, more work would be involved, just not unlike non-wash-and-wear clothing. But here is how I think about it: it may be less work to use a flattening iron every day than to cure yourself of leukemia, or even deal with painful rashes and breathing problems, in the long run. And learning to cherish whatever hair type you were born with is maybe not such a bad thing.
There is confusion about whether or not some of these keratin straightening procedures have more formaldehyde than others, and some even claim to not have any. Again, the problem is similar to the wash-and-wear clothing. In order for the procedure to work, you need a chemical reaction that involves either formaldehyde or molecules that have structures that work similarly, which is the root of what causes the rashes in the first place.
Formaldehyde in cosmetic products
I was out shopping and pondering formaldehyde, and coincidentally ran into my dermatologist, Dr. Diane Thaler. I used that opportunity to probe her knowledge of the chemical. She surprised me by revealing that it was indeed in several cosmetic products, causing her to change brands of shampoo during medical school, because the formaldehyde-containing ones made her head itch uncontrollably.
Wait a minute! I thought. I am an obsessive label reader. But I didn't remember ever seeing a bottle of shampoo or lotion or any sort of cosmetic product with "formaldehyde" on the ingredients list. That would be like seeing the word "carcinogen" on the label. I would have remembered that! What was going on?
When formaldehyde-free isn't
Diane's helpful references led me onto the trail of "formaldehyde releasers". They are not formaldehyde, but because they break down and release formaldehyde over time, they, like formaldehyde, increase the shelf stability of the product. That is how a product can expose you to formaldehyde and not have formaldehyde on the label. Quaternium 15, for example, is one of these, and according to my contact dermatitis textbook, it's the most common cause of contact dermatitis found in cosmetic products.
Here's a list of common formaldehyde releasers:
biocide DS 5249 (Proxel T)
tris hydroxymethyl nitromethane (Tris nitro)
hydroxymethylglycinate (Suttocide A)
Now, I sympathize with the desire to use preservatives, but there are smart ways of doing this, and not so smart ways. My first attempt at creating hand lotions in order to promote a local artist's work--her art was on the label--failed. I thought that vitamin E would preserve the product, but I should have added more, and perhaps used an additional backup. It turned out my all-natural ingredients were so yummy to various airborne fungi that several of the containers were quickly colonized with fuzz. I had on hand many all-natural petri dishes. I had to toss them. Damn those microbes, for they must have had a ball feasting upon all that expensive organic shea butter.
But there are ways to make products less appetizing to microorganisms by playing with more variables, and I am sure I didn't need a formaldehyde releaser to do the job. You can start by making a cosmetic product too acidic, too basic, too minerally, too dry, or too salty for most microbes to want to live in it, for example. Some "natural" cosmetic products are also preserved by pungent plant oils, although these can be just as irritating to your own cells as to microbial ones, though, because the mechanism works the same way on both cells (fragrant molecules called terpenes tend to dissolve cell membranes). If you have sensitive skin, it really does make sense to avoid even "natural" fragrances. Like I've said before, the origin of a molecule doesn't determine it's behavior.
How to reduce formaldehyde in your home—use green alternatives.
The most common source of formaldehyde in homes is from certain adhesives used in pressed wood products. The glue is either a formaldehyde-urea or phenol-formaldehyde resin. MDF, or medium density fiberboard, has the most resin per wood, and is therefore the worst offender. Other formaldehyde releasing materials include particleboard, hardwood plywood paneling, softwood plywood, and flake or oriented strand board.
Formaldehyde in buildings hit the media radar after thousands of residents of FEMA trailers inhabitants complained about difficulty breathing, asthma, and allergic reactions. About 83% of the trailers were found to have formaldehyde concentrations greater than what the EPA recommends.
Luckily, consumer demand has made widely available—as in your local Home Depot or other big box store—building materials made with alternative glues that don't release formaldehyde. As always, look at the label and do a little research before you buy. The more alternatives we demand and purchase, whether it is plywood, shampoos, or clothing, the more industry will listen and profit, and no one will get hurt.