When high levels of formaldehyde began showing up in FEMA trailers housing those left homeless by Hurricane Katrina, it was a reminder that this chemical is all around. It's in glue, plywood, plastics and carpet, for instance. But as the use of formaldehyde has increased, so have concerns about its safety. It's a chemical that has proved incredibly useful, but also hazardous.
"I can remember my father, if he got a cut or something, he would actually pour some formaldehyde on it, thinking it would disinfect, kind of like alcohol," says Ronn Wade, whose family was in the funeral business.
These days, Wade runs the Anatomical Services Division at the University of Maryland's medical school. That means he deals with about 1,500 cadavers each year.
Wade says he wasn't exactly surprised when studies began showing that formaldehyde could be toxic.
"Well, I kind of knew it was hazardous. I mean, when your eyes water and your throat burns and all that, that's your body telling you you probably need to get some fresh air," he says.
Chemists learned how to make formaldehyde in the mid-1800s. One of its earliest uses in the United States was to preserve corpses shipped home from the Civil War.
But early in this century, industry discovered the chemical could be used to make plastics. And by the 1970s, it was showing up in everything from foam insulation to construction glue.
"I could go into any house and I can find a formaldehyde-releasing product," says Thad Godish, an expert on indoor air quality at Ball State University in Muncie, Ind. He says scientists have known for a long time that it could cause health problems.
"Formaldehyde is a potent irritant," he says. "It's going to irritate the eyes, nose and throat. And one of the things that formaldehyde also causes is fatigue. It just wipes you out. You feel tired all day long. You feel like you haven't gotten a good night's sleep, and maybe you didn't, because it also interferes with sleep."
It can also cause asthma attacks, and long-term exposure is linked to cancers of the nasal passages and sinuses.
Those health problems prompted some government regulation, and lawsuits.
As a result, Godish estimates that between 1980 and 1990, formaldehyde emissions from a typical household product decreased by more than 70 percent.
Safety Remains an Issue
Today, the formaldehyde in consumer products such as glue tends to stay put — except under certain conditions.
"You increase the temperature, it starts to break down. You increase the relative humidity, it starts to break down. And if you increase both the temperature and the relative humidity, you have lots of formaldehyde released," Godish says.
Just the kind of conditions you find along the Gulf of Mexico, where the controversial FEMA trailers were sent. They were built with plywood and particle board that contained formaldehyde.
Godish says the concern about those trailers shows that the issue hasn't gone away.
And Wade, who preserves corpses with formaldehyde every day, says safety has become a big deal.
In the University of Maryland medical school, there's restricted access to the morgue, a state-of-the art ventilation system, and respirators with filters.
But Wade says he doesn't really think about how much formaldehyde he's inhaled in his lifetime. And that's partly because he's much more careful around formaldehyde than he used to be.