Fireworks and Safety [Part I]
Fact: Backyard consumer fireworks are the sole menace.
When the 4th of July rolls around each year, people flock to Mt. Rushmore to witness what is heralded as the most spectacular fireworks display in the country. And no one leaves disappointed.
The time-honored patriotic tradition brings generations together, in a family-oriented American way. It’s a happy night for most.
However, between 9,000 and 10,000 people are treated in U.S. hospital emergency rooms for fireworks injuries annually. Very few of these injuries come as a result of fireworks used by trained professionals. By far the most dangerous menace is the use of “consumer” fireworks, and few people understand the widespread magnitude of the risk (more on this in Part II). Eighty-five to 90% of fireworks injuries involve legal consumer fireworks, and it is rapidly becoming more than a once-a-year problem.
With a large assembly of people present during municipal Independence Day fireworks celebrations, there are numerous security precautions undertaken that police monitor throughout the day. Fire departments typically place a “grass truck” in close proximity to the fireworks show. Firms that are hired to produce the displays are under scrutiny and must strictly adhere to the demands of local jurisdiction.
For the show itself, shells (imported from Japan, Europe, or China) are secured inside a “main body” and connected to an electrical hookup called “the hot box,” by a distance of roughly 50 feet. The connection is made by low-voltage “squib” wiring, which contains an “electrical match” inside. The fireworks crew will strategically select an open area designated as the “drop zone” for falling ash. Shows normally run from 20 to 30 minutes. The City of Rockford, IL, spends $60,000 for its show before a crowd of 125,000. Chicago, with an estimated crowd of 1 million, spends more than $100,000 on its 4th of July fireworks.
The fire department or the police are typically in charge, and no fireworks go off until they give the go-ahead. Grassy areas, asphalt and other open ground areas such as high school tracks are wet down prior to the event, while officers on bicycles are on the lookout for drunks or “dangerous” individuals. A severe drought in 1996 was enough reason for several states, including Illinois and Texas, to cancel fireworks presentations in various counties. According to Glen Ellyn (IL) police officer Jim Burke, this “caused a lot of hate and discontent, but it was a smart move.”
Sales for all types of fireworks in the U.S. have doubled since 2000, a trend caused by the loosening of state regulations, resulting in increased sales of “backyard” fireworks. There were 11,400 fireworks injuries reported in 1995; 9,300 in 2002; and 9,600 in 2004 that required emergency-room treatment. The fact is that the private use of backyard consumer fireworks is the sole menace.
Statistics over the last 100 years bear out that public fireworks displays consistently account for a very small portion of injuries, since their use and control is in the hands of trained professionals. The safest way to enjoy fireworks is at public showings. By design, these are safe demonstrations under controlled settings and government regulations.
Insights From a Pyrotechnics ProI recently spoke with Pablo Cruz, a 24-year professional crew chief for Mad Bomber Fireworks Productions, Inc., an Elgin, IL, firm that stages fireworks displays for many cities. In his normal line of work, Pablo serves as a mechanic for the Chicago Transit Authority.
MB: What “hot content” do your fireworks contain?
PC: A lot of things - sulphur, copper, different types of metals, magnesium; whatever it takes to bring different colors into it. As far as the propulsion on it, it’s just a black powder mix.
During high winds, if landing firework sparks were to ignite dry brush, which content would be responsible for the burning?
Anything, but most of the time it’s the paper that surrounds the wick.
Have any of your workers ever been injured?
Never, not even any spectators.
What kind of safe circle do you maintain around the main body of the shells?
The main body consists of 3- to 15-inch shells. For every inch, we have to have a minimum 70-foot safe zone, without any spectators in there. So if it’s 4-inch shells, it’s 280 feet.
Do you use a different size squib for different size shells?
We use the same squib. It’s like speaker wire; an electric match is what it’s called. We use all the same stuff as far as wiring and detonation goes.
And that ignites the powder wick?
Yes. We call it the quick match. It’s dry powder with a string inside the shell, an electrical fire screw that runs 20 feet per second. The only thing that gets tricky is when you start synchronizing to music or anything else where you’re using a computer, and then you have to time out which color you want here or there.
How soon before the show do you load the shells ?
Three hours or so. But then we have to hook up all the wires and everything else. That’s a long procedure.
How far away will you be when you electrically discharge the fireworks?
Fifty to 70 feet for 4-inch shells for an all-electrical fire. We do some shows where we actually fire it off by hand - lighting each wick with a flare.
What other kinds of safety precautions do you follow when you’re setting up and when you’re operating the fireworks?
The number one thing is no flammables. We have no radio transmitters of any kind here; we don’t want them. Usually, the policemen are okay with their band, but we don’t want other radio bands coming near us. We clamp down the racks so that if one shell goes off in it and tilts it, it won’t tilt it down in a way that could shoot anything off at a spectator. The small shells we don’t worry about as much because the box has feet on it. But anything above the 4-inch box has got to be tied down tight. They’re tied up amongst themselves, on stakes angled in so that the box can’t move either way.
Are there two of you controlling which fireworks go off from two boxes of shells?
Typically, we’ve got it wired so the 3-inch go off first, and then the 4-inch. We have cakes going off in between there, and then the finale. The finale is all tied up into one continuous wick. We have two boxes, so it’s just safer if one guy is shooting off the fireworks and the other one is looking up at the sky to make sure everything’s going off in the right place that you want it. You’re not looking down at the button and then something’s coming at you.
Under what conditions would you decide to abort the show entirely?
If it’s raining, it’s not going. Any technician will judge on his own if it’s just too windy. Every time the wind picks up, like to more than 20 mph, you have to stand away another 70 feet per inch. If you get very high winds, we just can’t do the show.
How high will the 4-inch shells shoot into the air?
Most of them will probably go 400 to 500 feet in the air. I’ve shot as big as 15-inch. You get a higher elevation and you feel the concussion. It’s just taking off. It’s a nice display.
In Chicago, where you’re firing off a barge, is the main body wired differently?
No, it’s wired the same, but it’s computer synchronized. However, you don’t have the same safety distance, sitting 70 feet away. You’re sitting right next to everything because there’s no room on the barge.