Rust knew from her graduate class that BPA had existed for over a century. Invented in the 1890s, the organic compound became widespread in the 1940s and 1950s when the chemical industry began using it as the main ingredient in hard, translucent plastic called polycarbonate, which is typically marked with the recycle symbol “7” or letters "PC."

BPA was also used in epoxy resins, the basis for protective linings in water supply pipes and a variety of metal food and beverage cans. It maintained the quality of the contents, extended shelf life and prevented metal from affecting the flavors of food and drinks. In the following decades, BPA use exploded, showing up as an ingredient in products as diverse as baby and drinking bottles, bicycle helmets, compact discs and eyeglasses. By 2004, bisphenol A was such an important and ubiquitous element in various goods that America produced approximately 2.3 billion pounds of the substance. [1]

As it permeated the marketplace, BPA also found its way into people’s bodies: by 2004, 93 percent of the population over six years old had detectable levels of the chemical in their urine. The Food and Drug Administration and the EPA routinely pointed to 1980s studies by government regulators that found no serious effects from BPA. [2] But the proliferation of bisphenol A nonetheless triggered concerns about its safety. Opinions fell into two main camps: the first argued that BPA was safe for humans; the other that BPA was unsafe, both for humans and animals. This was because BPA, which mimicked the natural sex hormone estrogen, was an endocrine disruptor: a group of naturally occurring compounds or man-made chemicals that in animals interfered with hormone signals that regulated organ development, metabolism and other functions. Each side could point to scientific studies that buttressed its arguments.

After reading Rust and Spivak’s April 2007 story, Managing Editor Stanley wanted Rust to take a preliminary look at these competing claims, and explore BPA’s history, safety record, and anything else she could find to see if the chemical had the makings of an investigative project. “She’s writing about this synthetic estrogen plastic that’s in everything we eat practically, and I thought well, what kind of research has been done on this? Could this be a reason why breast and prostate cancers are rising so rapidly in human beings? And so that’s when we started asking,” Stanley says.

Sounding the ground. Rust, 36, had been toying with the idea of leaving the paper to spend more time with her young children. But Stanley’s request sparked her interest and she decided to stay. She started with a survey of the existing literature on BPA. She turned first to PubMed, a free digital archive of biomedical and life sciences professional journals provided by the National Institutes of Health (NIH). [3] A quick scan revealed that there was “a lot of buzzing going on in certain parts of the scientific community that this is really bad stuff,” Rust. [4] But the subject seemed to have received relatively scant press coverage. That was enough for Rust to tell Stanley that there might be grounds for an investigative reporting project. With her encouragement, Stanley in early June approved the creation of a three-person investigative team that, besides Rust, included Spivak and Meg Kissinger, both 30-year veterans of newspapers.

Although Rust was not a member of Katches’ “watchdog team,” Spivak and Kissinger were. Their project was put under Katches’ supervision.