Science plus safety

I have a fond memory of being seven months pregnant and, together with my Los Alamos National Laboratory coworker, filling a half-inch inner-diameter copper cylinder with my favorite explosive, erythritol tetranitrate. Over many months, we had synthesized the explosive and characterized its safety properties. With a team of people, we pressed it into pellets, machined and heat-treated the copper cylinder, and attached diagnostics for the experiment. 

The pellets were 3 grams each, and the tolerances were tight: there would be microns of space between the explosive and the cylinder walls as we placed the pellets inside the tube.  If a total of 30 grams of confined, high-performing explosive were to initiate next to us, we were well aware of the consequences: loss of life for ourselves and my unborn child. 

So, why is this a fond memory? With the careful risk analysis that we performed beforehand, using multiple subject matter experts, scientists, and controls, the task had become something far safer than driving my car to work that day. And I was grateful that even during pregnancy, I didn’t have to be afraid to participate in a project that I really cared about. Now, 10 years later, this is one of our favorite family stories, and the process is one of hundreds I’ve gone through to keep myself—and others—safe.

One of the special things about working with explosives is the way we can break down a potentially hazardous situation into its fundamental parts, so we can decide whether or how it could become safe. The most important first step is to ask “what if” questions with the right group of scientists, engineers, and managers. These knowledgeable experts each have thousands of hours working with explosives in relevant situations and can help answer tough questions. What if I drop this explosive and step on it? What if there’s a static discharge while I am holding it? What if the explosive scrapes against the side of the copper cylinder? 

Once we ask the questions, we assess the likelihood and consequences of the worst possible outcomes and determine if we can prevent or mitigate those. This process, known as hazard analysis, boils down to two questions: What’s the chance of something going wrong? And if something does go wrong, how serious will the outcome be?

If the chance of an accident is higher than one in 10,000, then the severity of the accident must be very minor (such as a small cut on a finger or lost time in an experiment). If the severity of the accident is anything close to loss of limbs or life, then the possibility of it happening must be one in a million, or even less. Otherwise, we implement controls that reduce the frequency or severity of an event to an acceptable level.

This is how we stay safe on the job, but this approach to handling hazards works in a variety of settings. As an open water swimmer, I’m often listening to concerned relatives and friends, and the night before a big swim I often lie awake worrying about currents, wind, waves, jellyfish, sharks, and hypothermia. Breaking down each potential hazard into pieces that I can either let go or control is very calming during the 2 a.m. hour and also the entirety of the swim ahead. For example, I decide not to worry about sharks, as my lifetime risk of a fatal shark attack is one in four million according to the Florida Museum of Natural History. However, after thousands of hours of swimming, I know I am almost 100 percent certain to encounter wind and currents, which means I must plan around these conditions during long ocean swims.

I also use risk analysis when deciding how much time I want to spend driving a car (there’s a 1 in 366 chance of an accident for every 1,000 miles driven) or determining whether I should eat raw cookie dough with my 7-year-old in front of my skeptical husband (1 in every 20,000 eggs are contaminated with salmonella, according to Centers for Disease Control and Prevention). My brother and my officemate, both pilots, employ risk analysis every time they fly. 

One of the things that makes our explosives community and Laboratory unique is that we aren’t afraid of the unknown. Instead, we face it with logical, thorough analyses that keep us safe. Some of my coworkers’ hobbies include baking, woodworking, hunting, hand-to-hand combat, and a variety of unusual outdoor activities. I sometimes think our methodical analysis of hazards is what allows us to do interesting things both at work and in our personal lives. We can separate things that simply sound scary from legitimate dangers we must avoid or mitigate. 

So, the next time someone tells you something is dangerous (or safe!), my advice is to go research the actual numbers that describe the frequencies of the hazards and the consequences of them happening. Understanding and analyzing risk is an important part of the scientific process, and it’s something we do at Los Alamos National Laboratory every day. ★

Virginia Manner is an explosives chemist in the Laboratory’s High Explosives Science and Technology group.