The History of REHS in California: From Sanitarians to Environmental Health Specialists

An 80-year journey from 1945 to today: how California's environmental health profession evolved, rebranded, and became a modern, specialized discipline.

The REHS exam exists because of a decision made 80 years ago. Understanding where this profession came from helps explain why the exam covers what it covers, why the 17 modules exist, and why California's environmental health standards are among the most rigorous in the nation.

This is the story of how California professionalized environmental health—and how a name change in 1988 reflected a profession that had grown far beyond its origins.

1945: The birth of the Sanitarian Registration Act

Senate Bill 319 (SB 319), signed by Governor Earl Warren, created the first registration program for Sanitarians in 1945. At the time, California's food and housing inspectors—called Sanitarians—had no formal credential or standardized expertise. The state legislature recognized the need to professionalize the field.

The original "Sanitarian" was defined as "a person trained in the field of sanitary science and technology who is qualified to carry out educational and inspectional duties and enforce the law in the field of sanitation." The focus was narrow: food safety, waste disposal, housing conditions, and basic public health hazards.

This was a landmark moment. California wasn't just regulating sanitarians; it was creating a national model for professional registration in environmental health. The Sanitarian Registration Act made it illegal to claim the title without meeting state standards. Other states would follow this framework.

The post-war expansion: 1945–1980s

In the decades following 1945, the profession expanded dramatically. The Cold War brought new environmental concerns: industrial pollution, nuclear testing impacts, hazardous chemicals. The 1970s saw the birth of the EPA and unprecedented environmental regulation. California's sanitarians found themselves managing not just food and housing, but water quality, air pollution, hazardous waste, and radiation exposure.

The profession was changing faster than the title acknowledged. A registered sanitarian in 1975 wasn't just inspecting restaurants and outhouses. They were testing drinking water for contamination, investigating disease outbreaks, managing hazardous materials, and enforcing increasingly complex environmental regulations.

The term "sanitarian" no longer fit. Worse, the public perception of the word was becoming a liability. Too often, people confused "sanitarian" with "sanitation worker" or janitor. The profession needed a rebrand that reflected its scope and expertise.

1986: The first amendment—preparing for retirement

In 1986, the California legislature amended the Sanitarian Registration Act to create a new classification: retired sanitarians could renew their registration at a reduced fee of $25 (rather than the full biennial renewal fee). This change, effective January 1, 1987, recognized the profession's maturity and allowed experienced practitioners to maintain their credentials in retirement.

To qualify for retired status, sanitarians had to be at least 50 years old or collecting retirement benefits, have worked as a Registered Sanitarian for at least 10 years in California, or have received an on-the-job disability before the 10-year requirement elapsed. This classification remains in effect today.

1988: The name change that transformed a profession

Two years later came the transformation. Assemblyman Trice Harvey carried legislation in 1988 that changed the official title from "Registered Sanitarian" (RS) to "Registered Environmental Health Specialist" (REHS). This was done with the support of the California Environmental Health Association to more correctly reflect the changing nature of the profession from sanitation to encompassing the total field of environmental health.

The name change was more than cosmetic. It reflected a fundamental shift in what the profession had become:

• From food and housing inspections to comprehensive environmental management
• From basic sanitation to toxicology, epidemiology, and hazardous materials
• From local enforcement to state and regional environmental protection
• From a single professional identity to a field that could encompass water specialists, air quality experts, disease investigators, and industrial health officers

Too often the public had viewed the term sanitarian with sanitation or janitorial worker and the name change was seen as a positive image enhancement. The profession now had a title that accurately reflected its expertise and scope.

The 1988 name change wasn't just rebranding. It was recognition that environmental health had evolved from inspection to science.

1990s–2000s: Modernization and specialization

After the 1988 name change, the REHS program underwent continuous modernization. The exam content expanded to reflect new environmental challenges: vector control, medical waste management, body art facilities, disaster response. Universities began offering dedicated degrees in environmental health, creating a more educated workforce.

CDPH implemented biennial continuing education requirements, ensuring REHS professionals stayed current with regulatory changes. The 17-module exam structure emerged, designed to test breadth across the full range of environmental health domains—not just food safety, but water, air, waste, toxicology, epidemiology, and specialized sectors.

Today: A mature, nationally recognized credential

The Environmental Health Specialist Registration Program is regulated by California Health and Safety Code Sections 106600-106735 and is administered by the Environmental Management Branch of CDPH. The program's mission remains what it was in 1945: to ensure that persons who perform environmental health work meet prescribed standards of education, training, and experience.

Today's REHS credential is nationally recognized. The exam reflects 80 years of evolution in the profession. The 17 modules test knowledge that didn't exist when the program began: toxicology dose calculations, vector-borne disease epidemiology, hazardous materials management, body art infection control. Yet the core purpose remains unchanged: protecting California's public health through professional competence.

Why this history matters to you

Understanding where the REHS program came from helps explain what the exam tests. It's not a random collection of topics. It's a profession that evolved to meet California's changing environmental challenges. Food safety appears heavily because that's where the profession began. Water quality is central because it became critical in the 1970s. Hazardous materials dominate because modern environmental health is about managing complex chemical and biological risks.

When you study the 17 modules, you're not just memorizing regulations. You're learning the accumulated expertise of 80 years of California's environmental health practice.

The bottom line

From 1945 Sanitarians inspecting outhouses to 2026 REHS professionals managing complex environmental risks, the profession has grown continuously. The 1988 name change marked a professional coming-of-age. Today's REHS is a credential that reflects scientific expertise, regulatory knowledge, and professional judgment. Understanding this history gives context to the exam and the profession you're entering.