Feb. 13, 2003 -- The nation's security level isn't the only thing that's been raised in recent days. So have questions about exactly how duct tape and plastic sheeting that is only slightly thicker than a garbage bag can go from being staples of building contractors to your recommended life insurance policy against a possible terrorist attack.
For answers, WebMD tracked down the scientist who compiled the actual recommendations released by the Federal Emergency Medical Agency, which advised Americans to keep both items on hand in the event of an attack using biological or chemical agents.
"The recommendations for sealing off a room with plastic sheeting and duct tape are based on what Israel has done since the 1980s to protect its people against chemical weapon attacks -- and were widely used during the Gulf War," says John Sorensen, PhD, research scientist at Oakridge National Laboratory, the Tennessee-based Department of Energy facility that is charged with devising emergency preparedness plans for several federal agencies.
"But rather than permanently seal off a specific room, as is done in most buildings in Israel -- where many homes are now built with a specific 'safe' room -- we wanted to develop measures that most people can take if there was one of these low-probability releases of a biological or chemical agent."
Sorensen tells WebMD that sealing off a room with these building materials, available at most hardware stores and home improvement centers, can offer "a significant level of immediate, short-term protection" for an hour or two -- the likely duration of danger from a possible biological or chemical attack. Plastic sheeting and duct tape would not offer protection against a nuclear attack.
"It is virtually impossible to make a room completely airtight, so you don't need to worry about not having enough fresh breathing air," he says. "Of course, we don't have a whole lot of information on the specific level of protection you might get from the actual agents that might be used. But in the limited number of simulated studies we've done, properly sealing off a room in your home or office increases protection against vapors of these agents as much as 90%, with an average protecting factor of at least 50% for those few hours. And in the event of a chemical or biological attack, that is the most likely scenario, as opposed to a gas tank that would slowly leak over a much longer period."
Why plastic sheeting? "It's relatively airtight and far better than sticking a towel under your door. And we know from tests that it's effective in its ability to keep liquids from penetrating. Since we would be dealing with vapors, which are harder to penetrate than liquids, it is likely the best choice," Sorensen tells WebMD. "We haven't looked into other types of tape, and recommend duct tape because it has been tested to show resistance to chemical agents and is widely available."
The actual level of protection you could expect from these home supplies depends on exactly where the agent is released in proximity to your home or workplace, what specific agent is released, and when. Since the answers to those questions are anybody's guess, here is what Sorensen suggests:
Buy the right materials. Duct tape, which usually comes in rolls of heavy gray-colored tape (though available in other colors) is recommended because it's sturdy, relatively airtight and widely sold. For plastic sheeting, go to the "building materials" section and look for rolls that are at least 4 mills thick, and preferably, the "heavy-duty" 6-mill thickness. "A plastic drop cloth available in the paint department could be used in a pinch, but because it is thinner, it's more susceptible to tearing." The recommended plastic sheeting is typically used as a vapor barrier when installing insulation, and comes in rolls that are three-feet or 10-feet wide and in varying lengths. Both retail for about $10 per roll.
Choose the right room. Ideally, you want to seal off an interior room, or another room that has the fewest number of windows, doors, and other openings to the outdoors. "The level of the room, whether it's in the basement or on the main or upper floor, is not as important as its exposure to outside air," Sorensen says. "The room shouldn't be too large, so don't assume a basement is the best choice. A bathroom or laundry room might be better, since they often don't have windows and aren't too large."
Seal off all openings. While the broad recommendations focus on sealing off windows and doors, don't forget about those other "openings." This includes all heating and air conditioning vents, electrical outlets and pipes. For instance, you should apply plastic -- or just duct tape -- directly over all outlets and vents so you cannot feel any incoming air, and also wrap the plastic around the holes in the floor where pipes are located. To wrap pipes, secure one end of the plastic around a pipe on one end and tape the other end to the bottom of your bathroom vanity. The plastic should be large enough to cover the casings -- or moldings -- around windows and doors on all sides, including the bottom of the door, which should be taped to the floor.
- Act quickly -- or before you need to. "In the event of an attack, you need at least 15 minutes to seal off everything, so I would recommend doing a practice run, or sealing off all openings beforehand and then doing the door once everyone is in the room." Because you need to work fast, Sorensen doesn't advise sealing the entire wall. "It would be harder to handle the rolls to get an uncut piece across an entire wall, and could eat up valuable time."
But if the unthinkable did occur, could these do-it-yourself techniques mean the difference between life and death?
"It depends on the agent," says Colleen Terriff, PharmD, specialist in infectious agents and their antidotes at Washington State University College of Pharmacy, who has developed domestic terrorism preparedness procedures for the city of Spokane. "Some are an immediate threat, when they are most highly concentrated. Some can suspend in the air for a while, but most will then fall to the ground. So in theory, it may provide protection -- but so will a strong wind blowing in the opposite direction. The important thing is that if you're going to tape your windows, you have to do it right."
However, don't expect plastic sheeting and duct tape to prevent smallpox and other biological outbreaks. "They are spread through person-to-person contact, and not through window cracks," she tells WebMD. "I think the best thing for people to do is be vigilant. But it's more important for healthcare facilities to be prepared to treat those people in the event of an attack."
Rick Greenwood, PhD, of the UCLA Center for Public Health and Disasters, which has evaluated different types of toxic agents, agrees that these building supplies may help, but again, it all depends on the agent used. "It's certainly better than nothing," he tells WebMD. "The whole idea is to limit exposure to potentially toxic compounds. What would likely happen is [that] upon release, those who were exposed would die. If you can't outrun the cloud, what you want to do is at least prevent contact or inhaling it.
"If you live near an American icon that is a likely target, it makes more sense to take these measures than if you live on a wheat farm somewhere. If you are concerned, it certainly can't hurt to have these things on hand."