How California's strict rules keep milk among the safest in the United States

Milk remains one of the most tightly controlled foods in the United States, with safety standards in place for over a century. In California, a mix of rigorous testing, inspections, and regulations ensures that dairy products stay safe from farm to fridge. The state's approach blends science-backed rules with the efforts of dairy farmers and processors to maintain high standards.

The foundation of US milk safety comes from the Pasteurized Milk Ordinance (PMO), first introduced in 1924 by the US Public Health Service. Over the decades, it has been updated repeatedly—most recently in 2019—to reflect advances in pasteurisation, pathogen controls, and testing. California's own regulations, managed by the CDFA's Milk and Dairy Food Safety Branch, align with the PMO while adding stricter measures. Between 2023 and 2025, the state has rolled out tougher raw milk checks for harmful bacteria, lower somatic cell limits, and extended pasteurisation times.

Oversight doesn't stop at the farm. Milk is checked during transport, at processing plants, and again before it reaches shops. Laboratories like the UC Davis California Animal Health and Food Safety Lab carry out accredited testing, while county, state, and federal agencies work together on inspections and licensing. Dairy producers also follow strict animal health, sanitation, and biosecurity routines to keep milk safe from the start.

National Milk Day, marking the first sterilised glass-bottle deliveries in the 1800s, highlights how far food safety has come. Today's rules ensure milk delivers key nutrients—supporting bones, growth, and health—without compromising on safety.

California's milk safety system relies on layered protections: science-based regulations, frequent testing, and close cooperation between agencies and producers. The state's latest updates to raw milk checks, pasteurisation, and cell counts show an ongoing commitment to adapting standards. For consumers, this means dairy products continue to meet some of the highest safety benchmarks in the country.