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Formaldehyde And Permanent Press Clothing: What’s The Harm?

Some of you may find this surprising, but I don’t mind ironing.  Unlike giving a lecture, writing a column or appearing on TV or radio, you get immediate gratification.  You see the results of your efforts.  Wrinkles that were there before are gone.  I suspect, however, that not everyone shares my enthusiasm for this task.  The textile industry realizes this as well and has responded by producing a variety of “durable press” fabrics that can withstand wrinkles.  But withstanding allegations of toxicity is more of a challenge.  In this case the hullabaloo is about formaldehyde, the chemical used to fashion garments that can come straight out of the washing machine and sidestep the ironing board.

Wrinkling is a direct consequence of the molecular structure of cellulose, the main component of cotton.  This polymer is made up of repeating units of glucose, but the important feature of cellulose, as far as wrinkling is concerned, is that adjacent molecules can form weak associations with each other.  These “hydrogen bonds” are responsible for maintaining the shape of the fabric.  But when cotton is moistened, water molecules insert themselves between the long chains of cellulose, cleaving the hydrogen bonds.  The cellulose molecules can now move relative to each other, and as the fabric dries and the water molecules evaporate, the hydrogen bonds reform holding the fabric in its new shape, which is usually wrinkled.  Another factor in wrinkling is the thickness of the cotton fibers.  Fabric woven with very fine cotton thread will crease less than fabric made with more coarse thread.

Heat can also disrupt hydrogen bonds, which explains how ironing works.  The weight of the iron flattens the fabric and the novel shape is then retained as the material cools.  Ironing with steam is especially effective because the added water molecules serve as an internal lubricant, breaking hydrogen bonds and allowing cellulose molecules to slide past each other.  As heat is applied, the water evaporates, hydrogen bonds reform, and we have a smoothened fabric.  At least until it gets moist from perspiration.

The earliest attempts to reduce wrinkling made use of starch, possibly as early as 800 BC.  Like cellulose, starch is made of repeating units of glucose, and the two substances have an affinity for each other.  A starch solution readily penetrates into cotton fibers and when the fabric dries the molecules of starch bind to each other forming a hard network, stiffening the fiber.  An analogy would be a canvas water hose that can be easily folded when empty, but becomes stiff when filled with water.  The problem with starch, though, is that it comes out in the wash and has to be applied each time.

The early part of the twentieth century saw the introduction of a number of synthetic resins such as urea-formaldehyde which presented textile manufacturers with an opportunity to “stuff” fibers with a substance that would not wash out as readily as starch.  It worked reasonably well, but when the chemical structure of cellulose became clarified in the late twenties, chemists came up with another idea.  Given that wrinkling is caused by the movement of the cellulose molecules relative to each other, why not find a way to form bonds between cellulose molecules that are not as easily disrupted by moisture as hydrogen bonds?

Formaldehyde was just the molecule for this task.  It readily reacts with the hydroxyl groups on cellulose to form cross-links, much like the rungs of a ladder.  The idea is to form the fabric into the desired shape and then treat it with formaldehyde to retain that shape.  Manchester textile manufacturer Tootal Broadhurst Lee was the first company to use this process commercially back in the 1930s, producing the world’s first “wrinkle-free” garment, the “Tootal” tie.  But it wasn’t long before a wrinkle appeared in the novel technology.  The garments released the irritating odour of formaldehyde.  Not only was this smell unpleasant, but formaldehyde was also responsible for the allergic contact dermatitis reactions that emerged with the use of the durable press fabrics.  Later there would be increased concern about formaldehyde treatments as studies began to show that at least in animals the chemical was a carcinogen.

By the 1990s significant improvement had been made in technology to reduce formaldehyde release from treated fabrics.  During manufacture the fabric was subjected to huge rollers that squeezed out excess formaldehyde followed by heat treatment in an oven to cure the formaldehyde and prevent it from being released.  Another method that requires less formaldehyde, known as “vapour phase technology,” involves hanging moistened clothing in an airtight chamber and treating it with a gaseous mixture of formaldehyde and sulphur dioxide to form the required cross-links.

A number of other cross-linking agents have also been introduced, with the most widely used ones being dimethyloldihydroxyethyleneurea (DMDHEU) and ethylene-urea/melamine-formaldehyde (EUMF).  While effective at producing wrinkle-free fabrics, they, like formaldehyde, can still cause allergic reactions.  Exposure to permanent-press fabrics should always be considered as a possible cause of dermatitis that has no obvious trigger.

Although the amount of formaldehyde released from permanent press fabrics is unlikely to affect health except for rare cases of allergic dermatitis, manufacturers have made determined efforts to reduce formaldehyde exposure.  The textile industry uses a “Sealed Jar Test” to measure the amount of formaldehyde released from one gram of fabric under controlled conditions.  Since the early days of durable press, the amount released has been decreased by a factor of ten.  Cross-linking agents that do not release formaldehyde at all, such as dimethylurea glyoxal (DMUG), have also been developed but they cost more and do not perform quite as well.

The advent in the 1960s of polyester fabrics with a greatly reduced tendency to wrinkle took some of the pressure off producing wrinkle-resistant cotton fabrics.  But since not everyone likes the feel of polyester, even when blended with cotton, the prospect of producing a truly permanent-press cotton fabric still looms in front of manufacturers’ eyes.  They’re getting there though.  Recently I bought some shirts that barely need the touch of an iron.  And as far as formaldehyde exposure from such fabrics goes, well, I think there are far bigger wrinkles in the fabric of life to worry about.

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Joe Schwarcz, Ph.D., is the Director of McGill University’s Office for Science and Society and teaches a variety of courses in McGill’s Chemistry Department and in the Faculty of Medicine with emphasis on health issues, including aspects of “Alternative Medicine”.  He is well known for his informative and entertaining public lectures on topics ranging from the chemistry of love to the science of aging.  Using stage magic to make scientific points is one of his specialties.


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One Response to “Formaldehyde And Permanent Press Clothing: What’s The Harm?”

  1. Kevin Morgan aka FitOldDog says:

    Nice article, thanks. Having worked and published on formaldehyde toxicity for many (too many?) years, the only concern I would have for low levels of formaldehyde exposure is the exacerbation of asthma. Otherwise, I wouldn’t have any worries, not that I (like any other toxicologic scientist) am free from error and misjudgment. Formaldehyde is everywhere, especially as a key player in intermediary metabolism. Fortunately, it is pretty reactive so it has trouble penetrating the bodies defenses. Haven’t thought about it in several years. -k @FitOldDog

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Richmond, VA – In an effort to simplify inpatient medical billing, one area hospitalist group has determined that “altered mental status” (ICD-9 780.97) is the most efficient code for use in any patient work up.

“When you enter a hospital, you’re bound to have some kind of mental status change,” said Dr. Fishbinder, co-partner of Area Hospitalists, PLLC. “Whether it’s confusion about where your room is located in relationship to the visitor’s parking structure, frustration with being woken up every hour or two to check your vital signs, or just plain old fatigue from being sick, you are not thinking as clearly as before you were admitted. And that’s all the justification we need to order anything from drug and toxin screens, to blood cultures, brain MRIs, tagged red blood cell nuclear scans, or cardiac Holter monitoring. There really is no limit to what we can pursue with our tests.”

Common causes of mental status changes in the elderly include medicine-induced cognitive side effects, disorientation due to disruption in daily routines, age-related memory impairment, and urinary tract infections.

“The urinalysis is not a very exciting medical test,” stated Dr. Fishbinder. “It doesn’t matter that it’s cheap, fast, and most likely to provide an explanation for strange behavior in hospitalized patients. It’s really not as elegant as the testing involved in a chronic anemia or metabolic encephalopathy work up. I keep it in my back pocket in case all other tests are negative, including brain MRIs and PET scans.”

Nursing staff at Richmond Medical Hospital report that efforts to inform hospitalists about foul smelling urine have generally fallen on deaf ears. “I have tried to tell the hospitalists about cloudy or bloody urine that I see in patients who are undergoing extensive work ups for mental status changes,” reports nurse Sandy Anderson. “But they insist that ‘all urine smells bad’ and it’s really more of a red herring.”

Another nurse reports that delay in diagnosing urinary tract infections (while patients are scheduled for brain MRIs, nuclear scans, and biopsies) can lead to worsening symptoms which accelerate and expand testing. “Some of my patients are transferred to the ICU during the altered mental status work up,” states nurse Anita Misra. “The doctors seem to be very excited about the additional technology available to them in the intensive care setting. Between the central line placement, arterial blood gasses, and vast array of IV fluid and medication options, urosepsis is really an excellent entré into a whole new level of care.”

“As far as medicine-induced mental status changes are concerned,” added Dr. Fishbinder, “We’ve never seen a single case in the past 10 years. Today’s patients are incredibly resilient and can tolerate mixes of opioids, anti-depressants, anti-histamines, and benzodiazepines without any difficulty. We know this because most patients have been prescribed these cocktails and have been taking them for years.”

Patient family members have expressed gratitude for Dr. Fishbinder’s diagnostic process, and report that they are very pleased that he is doing everything in his power to “get to the bottom” of why their loved one isn’t as sharp as they used to be.

“I thought my mom was acting strange ever since she started taking stronger pain medicine for her arthritis,” says Nelly Hurtong, the daughter of one of Dr. Fishbinder’s inpatients. “But now I see that there are deeper reasons for her ‘altered mental status’ thanks to the brain MRI that showed some mild generalized atrophy.”

Hospital administrators praise Dr. Fishbinder as one of their top physicians. “He will do whatever it takes to figure out the true cause of patients’ cognitive impairments.” Says CEO, Daniel Griffiths. “And not only is that good medicine, it is great for our Press Ganey scores and our bottom line.”

As for the nursing staff, Griffiths offered a less glowing review. “It’s unfortunate that our nurses seem preoccupied with urine testing and medication reconciliation. I think it might be time for us to mandate further training to help them appreciate more of the medical nuances inherent in quality patient care.”

Dr. Fishbinder is in the process of creating a half-day seminar on ‘altered mental status in the inpatient setting,’ offering CME credits to physicians who enroll. Richmond Medical Hospital intends to sponsor Dr. Fishbinder’s course, and franchise it to other hospitals in the state, and ultimately nationally.

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