8 Free Resources for California REHS Exam Prep

A curated, verified list of the free resources actually worth using before you spend a dollar on prep material, including a few candidates routinely miss.

We looked for a full ten resources worth recommending and stopped at eight, because the goal here is a list you can actually use, not a padded-out title. Every entry below is real, currently available, and something we'd point a candidate to ourselves. Two are our own free tools. The rest are official state documents, primary source law, and one outside study-materials page worth knowing about.

1. CDPH's REHS Study Guide

CDPH publishes its own REHS Study Guide as a free PDF through its Environmental Management Branch document library. It's not a substitute for a structured workbook, but it's the department's own framing of what the exam covers, straight from the source that writes the questions.

2. CDPH's "How to Become an REHS" guide

Also published by CDPH, this shorter guide walks through the registration process itself: eligibility, application steps, and what CDPH expects at each stage. Useful as a cross-check against any secondhand explanation of the process you've read elsewhere, including ours.

3. CDPH's REHS program page

CDPH's own Environmental Management Branch REHS page is the hub for its current forms, model training plan documents, and any updates to the registration process. Bookmark it and check it periodically. This is the ground truth for changes.

4. California Health and Safety Code, full text

The statute governing REHS eligibility (Section 106635) and out-of-state equivalency (Section 106725) is public law, free to read in full through California's official legislative information site. If you want the exact legal language behind an eligibility requirement rather than someone's paraphrase of it, this is where it lives.

5. California Code of Regulations, Title 22

Title 22 covers much of the environmental health regulatory detail the exam draws from, alongside CalCode. California's Office of Administrative Law maintains the official index and links to the current public regulations text at no cost. It's dense reading, but it's the primary source, and primary sources don't go stale the way a forwarded PDF does.

6. NEHA's REHS/RS study materials page

The National Environmental Health Association maintains a study materials page for its own national REHS/RS credential, which is a different exam from California's CDPH-administered one (we cover that distinction in California REHS vs. the National NEHA Exam). The subject matter overlaps enough, particularly on general environmental health principles, that NEHA's free materials are worth a look even for California-only candidates, as long as you keep straight which exam you're actually sitting for.

7. PassREHS's free practice quiz

Our own contribution: 451 real practice questions across all 17 exam modules, free with no account, email, or purchase required. Use untimed Drill Mode to work through weak areas, or the timed Exam Simulation to get a feel for pacing under real conditions. It's linked directly from our full quiz writeup and available any time at passrehs.com/quiz.

8. PassREHS's free companion PDFs

Three free downloads unlock with your email from our homepage: a Diagnostic Pretest to find your weak modules before you commit to a study plan, a Critical Definitions Flashcards set for the terminology the exam assumes you already know, and an Exam Day Practical Guide covering what to expect at the testing center. No purchase required for any of them.

What free resources don't cover

Everything on this list is genuinely useful, and none of it costs anything. But there's a real gap between free resources and a structured prep product, and it's worth naming honestly. Official CDPH documents tell you what's tested, not how to build a study schedule around it. The statute and regulation text are authoritative but not written for exam preparation, and reading Title 22 cover to cover isn't an efficient way to learn it. Free practice questions are valuable, but a single free bank doesn't replace repeated, structured drilling with explanations tied to a study plan.

If you've worked through the free resources above and want the structured version, that's what the PassREHS workbook and practice companion are built for.