The Poison Squad: Defenders of Food Safety | Serving Up Science

When you go to the store and pick up a gallon of milk, you're probably not worried about it being filled with formaldehyde, thanks to the FDA. However, it took some brave men to risk their health to bring food safety issues to light. On this episode of Serving Up Science, science writer Sheril Kirshenbaum and WKAR’s Karel Vega talk about the heroic act of the Poison Squad.


In the late 1800s – before we had modern food safety laws and protocols – food manufacturers were eager to add newly available chemical preservatives to foods, like the following:

·      Formaldehyde: an industrial fungicide, germicide and disinfectant;

·      Borax: a cleaning product; and,

·      Salicylic acid: commonly used today to treat acne and other skin conditions

And they had reason. America was changing quickly and so was our food. As large numbers of people moved away from farms into cities, food had to travel further without the convenience of refrigeration available.

People weren’t raising their own animals and vegetables anymore, but buying these products in stores. Producers found that new preservatives could keep milk from spoiling and chemistry could preserve meat. Science could save our food!

Of course, today we know that chemicals like formaldehyde and salicylic acid aren’t exactly the best things to eat. Manufacturers added borax to meat and copper sulfate to peas – to make them look greener. No one was evaluating these chemicals and their effects hadn’t been studied. 

Enter pioneering chemist, Harvey Washington Wiley, who had concerns that preservatives and additives, even pesticides and toxins, may be harming the public. And we now know, he was right.

Wiley worked at the U.S. Department of Agriculture, where he launched his “hygienic table trials,” renamed more memorably as the “poison-squad trials” by journalists.

He recruited 12 healthy, young men to the Poison Squad. He said they had to be “vigorous and voracious,” and had to have high moral character and take a civil service exam.

They had to have reputations for sobriety and reliability and had to pledge to eat only what they were given for an entire year and to be studied thoroughly throughout the experiment.

An aside but Wiley didn’t included women in The Poison Squad because he thought men were physically stronger and less likely to be harmed. Historically, many scientific studies and trials haven’t included women, which continues to be a huge challenge since we often differ in height, weight and body chemistry. 

Now the men in the Wiley’s study would be weighed, measured, and give hair and urine samples every day. And he poisoned them systematically with increasing amounts of different compounds to see what happened to people.

A volunteer letter for the Poison Squad.
Credit The U.S. Food and Drug Administration/Flickr/Public Domain

It may sound torturous but men volunteered for this. There are letters written to Wiley begging to be a part of this study. 

The experiment itself was rigorous and began with borax in increasing doses. And eventually the men got sick. 

Those that were given doses of formaldehyde began violently throwing up so they had to cancel that part of the test. But, borax was given to participants at lower doses and more gradually. If a dose was low enough, the men wouldn’t feel great, but they weren’t sick per se. Once the dose was increased, participants experienced upset stomachs, headaches and bloating. At times, men would throw up the doses as well.

The results of the research found their way to journalists and, eventually, the public, which led to demand that the government do more to protect Americans.

Pressure from this research led to the 1906 Pure Food and Drug Act, and eventually, along with Upton Sinclair’s The Jungle, which came out around the same time, the creation of the U.S. Food and Drug Administration (FDA). We owe a lot to Wiley, although his experiments are unconventional to say the least. 

In fact, today we remember Wiley as the father of the FDA. To learn more, pick up Deborah Blum’s 2018 book, The Poison Squad, One Chemist’s Single-Minded Crusade for Food Safety at the Turn of the 20th Century.