If you want to donate blood in the United States, there are a bunch of eligibility requirements you have to meet first. (The American Red Cross has a long list.) The purpose of these requirements are twofold: one, to ensure that the donor is able to donate without harming him or herself, and two, to reduce the chances that the donor has a communicable disease which may infect a recipient of the blood. While some of the restrictions are controversial, one — not listed by the Red Cross — may have saved thousands of American donees from receiving tainted blood. That restriction: a ban on blood banks from purchasing blood from prisons and, ultimately, from prison inmates. How do we know that prisoners’ blood had a disproportionate amount of problems?

Because Canada hadn’t instituted the same ban.

In the 1960s, it wasn’t uncommon for American prison systems to set up paid-for blood drives. Prisoners would give blood and the prisons, acting as a broker of sorts, would sell the blood and give a cut back to the inmates. Starting in 1964, Arkansas was one of the states which participated in these programs. By 1978, a company called Health Management Associates (HMA) won a contract to provide medical services to the state’s inmates — including running the blood donation program. Over the next few years, HMA sold prisoners’ blood for $50 a pop, according to the Encyclopedia of Arkansas, with the individual inmates receiving about $7 in scrip. Unfortunately, HMA’s oversight of the program wasn’t great. Pre-screening of donors simply wasn’t as good as it would be on the outside, with many carriers of HIV or hepatitis allowed to donate blood. And even when inmates were flagged as carrying communicable diseases, many of them complained when turned around. Arguing that they had a “right to bleed” — they wanted scrip — these inmates convinced organizers (often prisoners themselves) to look the other way and allow the otherwise-ineligible inmates to donate.

By the end of 1982, the U.S. Food and Drug Administration (FDA) advised would-be blood purchasers to eschew blood from inmates. This effectively ended the practice in the United States as the American Red Cross and other collectors and distributors of blood follow FDA requirements. However, many organizations outside the States did not follow FDA regulations and advisories. Specifically, the Canadian Red Cross continued to purchase blood from HMA, and, ultimately, from Arkansas’ inmates. Over the next decade, over 20,000 Canadians received tainted blood transfusions. Roughly 1,000 contracted HIV while the others were later diagnosed with hepatitis C.

In 1994, the scandal came to a halt. HMA stopped collecting donations from inmates. The Canadian government began an investigation the fall prior, issuing what is now called the Krever Report, after the presiding judge. The Krever Report concluded that the original source of the blood may have been obfuscated by HMA, which packaged the blood as coming from “ADC Plasma Center, Grady, Arkansas.” (ADC stands for “Arkansas Department of Corrections,” but this was left for the addressee to figure out.) But the Krever report did not absolve the Canadian Red Cross, which ended up paying criminal penalties. (Then-U.S. President Bill Clinton, who was governor of Arkansas during the period HMA administered the prison medical program, is often alleged to be blamed in the Krever Report, but in truth is never mentioned or otherwise referred to by the report.) Finally, the Canadian government, as a result of the scandal and due to the recommendations of the Krever Report, created a pair of organizations solely empowered to administer the nation’s blood supply, with Hema-Quebec entrusted to run Quebec’s and the Canadian Blood Service for the rest of the nation.

Bonus fact : Men who have had sex with other men (even once) on or after 1977 are ineligible to donate blood, per the FDA. This “lifetime deferral” of such would-be donors is something the Red Cross, America’s Blood Centers, and AABB (the leading organizations in the American transfusions world) have taken exception to, instead suggesting a 12-month deferral, which is the typical deferral for many other activities labeled “high risk.” On June 11, 2010, the U.S. Department of Human Services relevant advisory body opted to keep the lifetime deferral policy in place.

From the Archives: Type Cast: Japan’s cultural fascination with blood types.

Related: A bottle of blood.