How the US Revolutionized Milk Safety Over a Century of Strict Rules

National Milk Day celebrates a key moment in food safety: the first home deliveries of milk in sterilised glass bottles. This innovation transformed how milk was handled and consumed across the United States. Behind the scenes, strict regulations ensure that every glass remains safe and nutritious.

Milk safety in the US traces back to the Pasteurized Milk Ordinance (PMO), introduced in 1924. This law set national standards requiring all milk sold across state lines to be pasteurised. Before this, dairy-related illnesses made up roughly a quarter of foodborne disease cases. By 1917, 46 of the 52 largest cities had already adopted or encouraged pasteurisation, with the first state law following in 1947. Federal rules in 1973 then unified safety standards nationwide.

In California, one of the country's largest dairy producers, safety measures go even further. The state's program includes rigorous animal health checks, farm sanitation, and biosecurity protocols. During transport and processing, additional quality tests ensure milk remains uncontaminated. The UC Davis California Animal Health and Food Safety Laboratory carries out these checks, working alongside the CDFA's Milk and Dairy Food Safety Branch.

The result is a supply chain that delivers more than just safety. California's dairy families and processors provide milk packed with essential nutrients—supporting growth, strong bones, learning, and long-term health.

Today, milk stands as one of the most tightly regulated foods in the US. The PMO's century-old standards, combined with California's layered safety systems, keep contamination risks low. With every bottle and carton, consumers receive a product that meets strict health requirements while offering vital nutrition.