The two workers had been spray-painting the interior of a ship compartment—a small, unlit, unventilated and windowless room. As they began to walk out of the room after finishing the job, a flash fire ignited. With solvent fumes trapped next to their skin by coveralls, they suffered burns over more than 80 percent of their bodies.
What happened? This question soon became a legal one as the injured workers sued their employer, the paint company and several other parties. Was the paint defective? Had the operators of the ship-repair facility followed safety regulations and procedures?
As a consulting chemist specializing in coatings, I've been asked to investigate many cases where scientific evidence can be crucial in determining who is at fault. People have become used to seeing a scientist in the witness box, especially now that DNA evidence is common in criminal cases. But what's remarkable is how many other roles scientists play in the legal process. In 17 years as a "forensic chemist" I've appeared in court just five times. Many more times I've simply investigated the circumstances of a case with a scientist's eye, taught a bit of science outside the courtroom to a lawyer or a judge, or helped participants understand during the initial discovery process how certain hypotheses—and therefore certain claims—could be excluded as inconsistent with evidence.
Consider the case of the burned shipyard workers, one of whom unfortunately died. Photographs taken by a state inspector showed a trouble light (an incandescent bulb on an extension cord) in the room, a clear fire hazard. And the inspectors' interviews revealed that welders had been working on the outer plates of the ship room while the painting was under way. As a scientist I could conclude that the label warnings on the paint were appropriate, so that the paint was safe under normal conditions; however, the trouble light and welding each provided potential sources of fire initiation. These judgments on my part became factors in the settlement.
Typically, a case in my field deals with the failure of a coating, a safety question related to the coating or the alleged theft of a coating; typically, the chemist is called in by a paint company; and typically, the case ends in a settlement. In most cases I haven't known at the outset what role I would play—beyond, perhaps, preparing an analysis and report.
Legal action was threatened, for instance, against a contractor who had subcontracted some painters to apply a dark-brown latex paint on window and door frames after construction was complete on some condominiums whose exterior was unpigmented stucco. Brown paint streaks appeared on the stucco, and the contractor couldn't wash them off.
I knew just enough about San Francisco weather and latex paint to figure out that if the painters stopped work just before dusk each evening (as they said they did), the paint they applied might have been diluted by the condensing evening fog that comes through the Golden Gate, draining pigment from the painted surface onto the stucco. Still, the homeowners needed a remedy. I bought a small low-pressure sand blaster and a bag of talc and showed them how blasting the surface with a soft mineral would clean the stucco without scraping it. I was to give no star performance in the witness box in this case; instead I managed to stop a lawsuit and provide a practical remedy.