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Halloween is upon us. As the fake furry spiders and cotton-woolish ersatz webs proliferate, what should really scare us is injudicious use of dry ice in decorative pseudo-cauldrons and elsewhere.
A lot of attention is given to the dictum: don’t touch, and certainly don’t eat and don’t swallow, dry ice. This scenario of misadventure is familiar although not all that common. The first medical report seems to have appeared in 2004, telling the story of a 16-year-old girl who developed severe stomach pain while attending a wedding banquet in Taiwan. She had swallowed a mouthful of a drink containing small pieces of dry ice. Although this can also be the stuff that bartender bad dreams are made on, liquid nitrogen is the bigger deal on the designer cocktail circuit.
What often gets minimized or left out altogether when it comes to dry ice cautionary tales is oxygen deprivation. The equation is simple but overlooked at one’s own peril: too much carbon dioxide = too little breathable air, leading to asphyxiation. This can happen whenever a whole lot of dry ice is left to warm up in an enclosed space. Notice I did not say melt, because that is something dry ice does not do on the surface of the Earth, where it turns right into a gas (chemistry class memory teaser: “sublimation”) . Maybe Venus once had oceans of carbon dioxide, but not here.
Unfortunately, cases of dry ice-caused deaths are not as rare as they should be. A year ago, for example, the St. Louis Post-Dispatch carried a story, “Freak dry-ice death spurs West County woman to action,” about a sister’s quest to publicize her brother’s asphyxiation doing a produce delivery. Paramedics had found him unconscious in his automobile with the air conditioner running on a hot day (thus recirculating the air inside). On the back seat there were five boxes of strawberries chilling with dry ice.
It turns out that the cab of a vehicle loaded with dry ice makes for a particularly efficient chamber of horrors. In 2004, the Centers for Disease Control, emphasizing the make shift use of dry ice for refrigeration following natural disasters, described a 34 year old man who “purchased a 100-lb block of dry ice from a local ice house. The block of dry ice was divided into four equal parts and packaged in brown paper bags, which were placed in the front seat of the man's pickup truck. The windows were closed, and the air conditioner was set to recirculate air inside the cab of the truck.” This story had a happier ending that many. “After driving approximately one quarter mile from the ice house, the man had shortness of breath; his breathing difficulty increased as he drove the next mile. The man telephoned his wife and asked her to call 911. He then pulled his truck into a parking lot, parked, and lost consciousness. His wife drove to the parking lot and located her husband's truck; immediately after she opened the door to the vehicle, her husband began to awaken.”
There are other scenarios of fatal dry ice encounters as well, some of which have been captured in medical journal reports such as: asphyxiation due to dry ice in a walk-in freezer, death in a man fleeing a confrontation in a dry ice factory who hid in a small box used to store ice and food, and, perhaps the most genre-bending, “Carbon dioxide asphyxiation caused by special-effect dry ice in an election campaign.” There are likely many other cases that never get documented in a biomedical report. There may even be some reports that simply are apocryphal, such as one (file it under urban legends) of a church that, using its sanctuary as a haunted house, had a plank across its dry ice filled baptismal pool. A man underneath was supposed to grab at the ankles of those crossing over. He, of course, was the one that crossed over, according to this tale.
Which brings us back ‘round to Halloween. One marketer (motto “Delivering Excellence in Dry Ice”) which has 43 sites across the U.S. selling at a 10- pound minimum, promotes on its website “Dry ice is the best way to get that creepy, spooky graveyard effect for Halloween! Read below to learn how to use dry ice to create special effects for Halloween such as fog, spooky jack-o-lanterns, and ghostly floating bubbles!” There is an accompanying video and promotional narratives for Dry Ice Fog Effect, Witches' Brew - Dry Ice Punch for Halloween, Spooky Jack-O-Lantern with Dry Ice Fog, Spooky Crawling Bubbles from Dry Ice (“Combine dish soap and dry ice to achieve this spooky effect for Halloween”), Halloween Laser & Fog Fun, and Ghostly Floating Bubbles. Following this list, there is also a click-on safety sheet (Dry Ice Safety Tips). That advisory includes the information that “Dry ice changes to CO2 gas as it sublimates, causing a lack of oxygen. Only use dry ice in open or well-ventilated areas. Do not store in confined spaces such as vehicles and never store near an area where people sleep as suffocation could occur.”
Despite sublimate and suffocate, this warning at least comes in at a consumer friendly, eighth grade reading level. Halloween pranks and festivities, Grade 7 and lower, don’t count.
