Source: NYT > Health
Article note: It took me a minute to figure out what they were going on about about because the article is all emotional pleas no content.
They're talking about Sodium Nitrite. The extremely common preservative/curing agent used in meat curing and sausage making (its why hot dogs have that pink color).
Its LD50 is like 71mg/kg, it's less dangerous than most cleaning products.
Even as grieving families tried to warn Amazon and other e-commerce sites of the danger, there were more purchases and more deaths. 