For California REHS Candidates

The California REHS Examination Workbook

Prep for the CDPH Registered Environmental Health Specialist exam, written by a working California REHS. Covers CalCode and CCR Titles 17 and 22 directly, not adapted from a national prep book.

Coming soon to Amazon — $44.95 Free companion materials
REHS
The California
REHS Examination
Workbook
A California study guide for the CDPH REHS examination
Comprehensive Second Edition
By Paracelsus
324
Pages
17
Modules
566
Practice Questions
Contents

Seventeen modules covering the CDPH examination scope.

Organized for working through over twelve weeks, or for a fast review the week before.

Module 01
General Environmental Health, Statutes & Administration
Module 02
Food Protection & CalCode
Module 03
Communicable & Foodborne Disease
Module 04
Dairy & Milk Science
Module 05
Potable Water (Drinking Water)
Module 06
Liquid Waste & Wastewater
Module 07
Solid Waste Management
Module 08
Hazardous Materials & Underground Storage Tanks
Module 09
Medical Waste
Module 10
Recreational Health (Pools & Spas)
Module 11
Housing & Institutions
Module 12
Vector Control & Pest Management
Module 13
Air Pollution & Toxicology
Module 14
Light, Noise, Radiation & Sampling
Module 15
Disaster Response & Personal Protective Equipment
Module 16
Body Art Facilities (AB 300)
Module 17
Epidemiology Concepts & Calculations
+
Four appendices, two quick-reference sheets, glossary
Why This Workbook

Built for the California exam, by a California REHS.

California-specific from the first page

Most national REHS materials treat California as one state of many. This one starts with CalCode, CCR Titles 17 and 22, and the California content CDPH tests. Federal material appears only where the exam covers it.

Written from inside the field

The author has worked across retail food, pool and spa, body art, and housing inspections in a California county program. The scenarios in the modules come from that work, not from a textbook.

Every cross-reference resolves

525 internal cross-references connect questions to source material. If a question cites §5.7, you can flip to §5.7 and find the section the question was built from.

Diagnostic pretest with scoring guide

A 40-question diagnostic with a four-tier readiness rubric tells you which modules need the most attention before you waste weeks reviewing material you already know.

Regulatory citation index

Sixty-plus California statutes, regulations, federal codes, and named acts are indexed in Appendix D, each with the module(s) where it appears.

Free Companion Materials

Three free downloads with every workbook.

One to plan your study, one for the final week, one for exam day.

PDF
D

Diagnostic Pretest

A 40-question self-assessment with answer key and four-tier scoring grid. Take it first to see where you stand before committing to a study plan.

Download PDF →
PDF
F

Critical Definitions Flashcards

137 term-definition pairs from Appendix B, formatted as four print-and-cut flashcards per page, double-sided. Print on cardstock, cut along the guide lines, and carry the stack with you.

Download PDF →
PDF
E

Exam Day Practical Guide

What to bring, what to expect, what to leave behind, the two-pass strategy, and what to do if you don't pass on the first attempt. Four pages of practical preparation.

Download PDF →
Who This Workbook Is For

If you're sitting for the California REHS exam, this is for you.

EH Trainees

Recent graduates in EHS Trainee roles, getting ready for a first attempt at the exam.

Career Changers

People moving into environmental health from public health, biology, chemistry, or a related field who have no California exam background yet.

Repeat Candidates

Candidates who came up short the first time and want a tighter, California-focused review for the retake.

Out-of-State REHS

Credentialed REHS coming in from another state for California reciprocity, where the gap is the California law, not the science.

EH Program Instructors

Faculty in California EH programs (CSU, community college) looking for a current supplement to their course materials.

County Training Programs

County EH departments who want a clear study reference for their EHS Trainee onboarding.

About the Author
Paracelsus
Veteran California REHS

Paracelsus is the pen name of a veteran California Registered Environmental Health Specialist with over a decade of supervisory experience in local enforcement. The author has run inspection programs in retail food, public pools and spas, body art facilities, detention facilities, and housing, and has trained and mentored REHS candidates from the trainee phase through the certification exam.

The pen name honors the Renaissance physician and toxicologist who first articulated “the dose makes the poison.” It's the principle behind most of the science the REHS exam tests.

It's the resource the author wishes had existed when he first took the exam.

Common Questions

Frequently asked questions.

Is this workbook current for the latest REHS examination?
The Comprehensive Second Edition (v2.2, 2026) covers the current CDPH examination scope and reflects California law as of the publication date. California rules amend often; check the current text of any cited section before relying on it for the exam.
How does this compare to the CDPH Study Guide?
The CDPH Study Guide is the authoritative scope reference and should be your primary source. This workbook builds on it with practice questions, scenarios, mnemonics, and cross-referenced rationales the CDPH guide doesn't provide.
How is this different from other REHS prep materials?
Most REHS prep materials are written for the national exam and treat California as one state of many. They cover foundational concepts well but are thin on CalCode, CCR Titles 17 and 22, AB 300, and the other California content CDPH tests. This workbook starts with California's regulatory framework and is written by an author who works under it.
How long does it take to work through?
The included twelve-week study plan structures the workbook for systematic preparation alongside a working schedule. Candidates closer to their exam date with strong baseline knowledge can compress to a four-to-six-week intensive review. The diagnostic pretest in the front matter helps you decide.
Are the practice questions representative of the actual exam?
The questions are calibrated to test the same competencies as the CDPH examination, formatted in the same four-option multiple-choice style, and grouped by module to support targeted review. They are practice questions, not actual examination items, and CDPH does not publish the official pass point.
Will the workbook be updated?
Yes. If you find an error — a typo, an outdated citation, an ambiguous question — report it through the contact link on this page. The author confirms each report and incorporates the fix in the next printing. A version history at the back of each release shows what changed.
Coming Soon

Ready for your REHS exam?

The Comprehensive Second Edition (v2.2) launches soon on Amazon in paperback at $44.95. Drop your email and we'll let you know when it's live.

No newsletter. One email when the book launches, then nothing else.