#SkepticalTuesdays: Dryer Sheets | Vol. 2 / No. 31.1

Baby for added cancer fearmongering?
Baby for added fearmongering?

Everything is toxic and everything is going to give you cancer.

I mean basically everything, right? At least, according to my facebook feed. I don’t know how this happens, really. Is it a personal failing? Am I not spreading enough science around to counteract this stuff? Is running a blog not enough? [why yes, that is an ironic tone of voice I was using] I can’t say. But I can say this: I don’t think you’re likely to get cancer from your dryer sheets.

Want to know something else? I think — and for friends of mine, they’ll know how insane this is for me to type — ALEC is right on this one (or would be if they said it): It’s ‘junk science.’ But for the sake of narrative, let me start again.


So the above image macro popped up in my facebook feed this week, with its claim (written over a concerned-looking baby, as all reason-based health advice tends to be) that “fabric softener is the #1 cause of indoor air pollution. Whenever you smell that ‘laundry smell,’ you are inhaling toxic VOC’s.”

Like any reasonable person, then, I did a little digging. Because surely — surely — if dryer sheets were spreading about toxic compounds there’d be someone talking about it.

I stumbled upon a whole lot of woo, and a couple of links that might’ve been somewhat credible. Someone over at Daily Kos, a site with an admittedly leftist bent (that I usually approve of) even tried to use a study on dryer sheets as a stick to beat noted right-wing, money-and-power-for-the-moneyed-and-powerful group ALEC (the American Legislative Exchange Council) over the head with. Not having a degree in any kind of science (not even library science, sorry guys) I’m usually quite sympathetic to the fight against people telling me I can’t understand the science behind something. But when the author at Daily Kos writes “but then to ALEC, I’m an ignorant average citizen unable to evaluate the reliability of ‘junk science’,” I’m forced to agree.

In this case, you couldn’t.

All the woo (and all the dubious science) stems back to one person, a Dr. Anne Steinemann, “professor of civil and environmental engineering and public affairs at the University of Washington.” Her mode of operation seems to be quite simple: find something smelly, determine that it gives off chemicals, “???”, and… profit? (I don’t know if she actually profits or what). The dryer sheets thing seems to stem from a study she performed in 2011, so I’ll focus on that, but most of the things I’ve come across have seemed pretty weak, even to someone like myself.

The study, performed in 2011 (but published in the March 2013 issue of Air Quality, Atmosphere and Health, it seems), can be found here, but it’s behind a paywall, so I’ll do a little description.

Steinemann, et al., went to two volunteers’ homes and used their washers and dryers for the test. The washers were different, with one being a top-loader, and one a side-loader. Both washers and dryers had previously been used to wash and dry clothes treated with “fragranced products,” though one more than the other. The “dye-free 100% organic cotton” towels were all the same brand, and brand new, aside from being rinsed and dried off-site in a completely separate washer and dryer. They cleaned the washer and dryer each with white vinegar and paper towels and then ran them empty to set up the test.

The testing was done at four points: first, they took 2g samples of their detergent and dryer sheets, both “fragranced,” stuck them in bottles, and left them overnight to get samples of that air; second, they took air samples from the dryer vents fifteen minutes into the dryer cycles with a) the towels washed in just water, b) the towels washed in detergent, and c) the towels washed in detergent and dried with dryer sheets. Then they had those samples analyzed for their contents.

Are you seeing the problems yet?

As for the data, well, it’s not a much better story. I’ll put down just the two compounds which everyone seems to single out, acetaldehyde and benzene, because, as the study says, these two “are classified as carcinogenic” and have “no safe exposure level.” “1” and “2” are the sites, and “a”, “b”, and “c” are just the towels, detergent, and detergent and dryer sheet, respectively, in micrograms per cubic metre (μg/m³).

Compound 1a 1b 1c 2a 2b 2c
Acetaldehyde ?? 36 22 41 47 36
Benzene ?? ?? ?? 2.7 ?? 2.2

Those question marks are just blank spaces in their data table. The compounds found in the “leave it overnight” selection were only listed for presence or absence (not in actual amounts) and found a) no benzene in either sample, and b) acetaldehyde present in the air from around the dryer sheet.

The things wrong with this study are just legion. Let’s just assume for a moment that we can forgive the fact that these are residential washing machines with unexplained histories, because that’s actually the least crazy thing about this study (if you can believe it). There are no controls: why didn’t they use two types of towel? Or three? Why didn’t they test the offgassing of the towels overnight? Why didn’t they test the dryer air with an empty dryer? Why didn’t they run the experiment with the towels after multiple subsequent washes to see if it’s an artifact of new towels? Why didn’t they try two kinds of detergent? Why didn’t they try two kinds of dryer sheet?

To claim this study isn’t “rigorous” isn’t enough; this study’s methodology is laughably poor.

And then there are the data: why does the just-towels run at site 1 produce neither of the chemicals, when the same test at site 2 produces 41 μg/m³ and 2.7 μg/m³ respectively? Why is no benzene detected in site 1 at all, and why is there none detected in the detergent-only run at site 2? How can we believe any of the data when the data are so inconsistent? How can we attribute any of the measurements — if we do assume those taken are correct and those missing would line up with the others — to the dryer sheets? And even if we DO: the dryer sheets seem to lower the amount of acetaldehyde and benzene in the samples!

Between the godawful experimental design and the resulting lacking data, this study tells us essentially nothing of any value whatsoever, except maybe what we probably already knew: don’t push your face up to the dryer vent when it’s running and take a lot of deep breaths. Or at least don’t do it on a regular basis, and even then it might not have any major effect on your health.

The craziest part of it is that you don’t need to even know that she associates with people like Joseph Mercola or that her top ten Google hits are for her personal website (and tribute to the 1990s internet) “drsteinemann.com.” You don’t even need to read a crazy bit of prose like this:

Although the authors did not seek to assess whether use of any of the products studied would be associated with any risk, Steinemann says she receives hundreds of letters, phone calls, and e-mails from people who report a variety of respiratory, dermatological, and neurological problems they attribute to scented products: “Children have seizures after exposure to dryer sheets, and adults pass out around air fresheners,” she says.”

All you have to do is look at the study and you’ll know there’s only one way to describe it.

Junk science.


Richard Ford Burley is a doctoral candidate in English at Boston College, where he’s writing about remix culture and the processes that generate texts in the Middle Ages and on the internet. In his spare time he writes about science and skepticism here at This Week In Tomorrow.