NOVA: What are your greatest concerns in terms of firework safety?
Conkling: Well, safety begins with manufacturing. Manufacturers are very
cautious to avoid any type of ignition source when they're mixing powder
together, when they're assembling fireworks. They have large amounts of powder,
so there is always a potential for a serious accident to occur. Training and
good safety practices are important.
When using fireworks at the consumer level, one should follow the label
directions very carefully and have a sober adult in charge. At the big public
displays, the biggest concern for the public is giving the professionals room.
The safety zones they set up are there for a reason. Stay back a safe distance
and enjoy the show.
NOVA: Today, there are some states where you can't buy fireworks but you can
buy firearms. Should fireworks be legal in every state?
Conkling: We now have very strict federal regulations for consumer fireworks.
All 50 states currently allow the licensed public display to take place. There
are now, I believe, 41 states that do permit the public to use something,
ranging from the wire sparklers in novelties up to a reasonable assortment of
consumer fireworks. All those have to meet federal safety standards of the
Consumer Product Safety Commission. I believe that devices that meet those
federal standards, used in an appropriate place by a reasonably competent
person—again, the sober adult comes into play—can be used safely and
enjoyably. It's not necessary to prohibit them.
Two words should define the user
of consumer fireworks, says Conkling: "sober adult."
It's important to allow devices appropriate for the area, however. In a
populated area, you may not want the aerial rockets, for example. But fountains
that stay on the ground and spray sparks can certainly be used very safely in
NOVA: You now serve on an international fireworks body, right?
Conkling: Yes. There's currently an effort to harmonize the international
standards for fireworks, both their classification and performance, and I've
been asked to participate. We've been working to try to make it much easier to
exchange fireworks between countries, so everybody's working with the same set
NOVA: How did you first become interested in fireworks?
Conkling: As a youngster I was fascinated by them, but it was more through the
chemistry. When I started my college teaching, I began doing research with
pyrotechnic materials and found it to be an absolutely fascinating area of
chemistry, with a lot of questions that were not fully answered at the time.
It's a beautiful field to do experiments in. When you get your red flame or
blue flame, it's very positive feedback that makes a lot of other areas in
chemistry pale in comparison.
"If it's a nice, deep, vivid blue,"
says Conkling, "I sort of take my hat off and say, 'Well, those people knew
what they were doing.'"
NOVA: Have you invented fireworks yourself?
Conkling: I've developed various compositions in both the fireworks field and
other areas of pyrotechnics, including military applications and other civilian
areas, such as emergency signals, particularly delay compositions or
NOVA: What's your favorite kind of firework?
Conkling: I love a really good blue shell. To a chemist, the blue color is the
hardest to achieve. When I go to a fireworks show, I always keep an eye out for
the quality of their blue. If it's a nice, deep, vivid blue, I sort of take my
hat off and say, "Well, those people knew what they were doing."
NOVA: What's the most dazzling display you've ever seen?
Conkling: When the American Pyrotechnics Association had its 50th
anniversary in 1998 at Disney World in Florida, the "best of the best" in the
industry put on a salute that was fired from multiple sites. It was absolutely
spectacular. I give that the highest rating of any show I've ever seen.
Firework shells typically run
up to about 12 inches in diameter, but shells over three times as big have had
their day in the sun.
NOVA: And what's the largest firework anyone has ever set off?
Conkling: In practice, shells tend to run up to about 12 inches in diameter.
The U.S. uses a few every year that are 24 inches in diameter, and 36-inch
shells have been made. The biggest that people have tried to make were in the
In the mid-1970s the author George Plimpton launched an effort get monster
shells called Fat Man I and Fat Man II to explode. The first one went off at
ground level and was deemed a failure. The other got up a few hundred feet and
burst, and was apparently quite spectacular. But I'd say 24 is about as big as
anyone can go and have any hope of a successful shell.
NOVA: How big across is the resulting burst of a 24-inch shell?
Conkling: Probably 1,000 feet. There's a tremendous spread to the "stars" [the
cube- or pellet-shaped chemical constituents of fireworks—see Anatomy of a
NOVA: Different cultures have different styles of fireworks displays, is that
Conkling: Yes. Many of the European countries love noise. There, colors are for
the women and the kids, but the real fireworks effect is the concussion. In the
United States, I think we're much more into beautiful color displays.
The Japanese are into symmetry. They judge the quality of a firework by the
perfect symmetry of the burst. There cannot be the slightest imperfection in
the symmetrical pattern. They have international competitions in which
companies compete, and it's a matter of great pride to be judged the top
American display shows typically prefer a cosmopolitan range of firework
NOVA: Do these different styles drive the type of manufacturers that are
working in different countries?
Conkling: Yes. Now, since the U.S. has traditionally been the melting pot of
the world, we tend to take the technologies from all of these countries. A
fireworks display today is really an international event. You'll see Chinese
fireworks, Japanese fireworks, maybe some Australian fireworks, Brazilian
fireworks, French fireworks, and Spanish fireworks as well as U.S.-manufactured
product. We do much more internationalization in our fireworks shows today than
most other countries.
NOVA: I've heard Japan does daytime displays. How does that work?
Conkling: Many of the daytime fireworks are smoke effects. When the firework
bursts, a smoke cloud is produced. You can create various colors and visual
patterns through the use of the smoke rather than through a burning light
NOVA: In closing, why do you think people love fireworks so much?
Conkling: Well, obviously people like the glorious entertainment—the bright
lights and vivid colors and loud noises. But there is something in the human
spirit that is somewhat in awe when these fireworks explode, something that
gets to some of our basic instincts. It's more than the pretty colors or pretty
lights. It goes right back to man's fascination with fire.
Interview conducted by Peter Tyson, editor in chief of NOVA Online