What’s covered
The whole curriculum, in the order you take it.
ANSI Z133-2026 is the safety standard for tree work, and it is written to be consulted by people who already know the trade rather than read start to finish. This is that document taught in sequence — what each module covers, how long it takes, and what you will be able to do at the end of it.
- Built on
- ANSI Z133
- The 2026 edition
- Modules
- 7
- Holding 50 lessons
- Reading time
- About 8 hours
- At your own pace
- Pass mark
- 70%
- On one final assessment
The modules
Seven modules, taken in order.
Each one opens on a job you have been on, states what Z133 requires, translates that into what you actually do, and then shows where crews get it wrong. Nothing unlocks out of sequence, and nothing is timed.
Module 1Introduction: Why ANSI Matters
Where Z133 came from, who it binds, and how something voluntary ends up deciding what your employer can ask of you. It covers the committee that wrote the standard and why, the test for whether it applies to a job at all, the route a voluntary document takes through OSHA enforcement, the line between Z133 and A300, and what you are personally answerable for.
Module 2General Safety, PPE and Job Briefings
What has to be true before work begins — the briefing, three separate inspections, the gear, and being ready for the day it goes wrong. It carries Section 3 in order: what a briefing has to contain and when a second one is required, the electrical, tree and underground checks that precede it, the protective equipment each task calls for, how a crew agrees to talk and where things land, and what has to be ready before anybody is hurt.
Module 3Electrical Hazards
The longest section in Z133, and it credits exactly one thing with protecting you: distance. It runs from how contact actually happens, through the four qualification levels and the approach distance each one carries, to the gear that protects you from none of it, the ground around a truck, and the conditions that stop work.
Module 4Vehicles, Equipment and Aerial Devices
Every machine on the job, and the one rule underneath all of them: stopped, keyed out and owned before a hand goes near it. It covers the inspection before a unit moves, siting and working an aerial device, the plane of the chipper's infeed hopper, the grinder and the winch that endanger somebody other than the operator, the arborist on a crane hook, and the machine run by remote control.
Module 5Chainsaws, Power Tools and Hand Tools
A tool is in service or it is out of it. There is no third state, and no version where a crew-made repair to a safety device counts as a fix. It covers what a power tool has to be before it starts, how a saw is started and held, what happens to it between cuts, reading tension and compression before cutting, the hand tools you swing, and ladders.
Module 6Tree Climbing, Rigging, Removal and Aerial Rescue
The longest module in the course, and one idea sits underneath it: almost every failure here happens at a transition. It runs from the systems Section 8 applies to and the rope and connector specifications they demand, through choosing a tie-in point and repositioning on it, into rigging forces and drop zones, felling, aerial rescue, and palms.
Module 7Plant Health Care, Pesticides and Support Systems
A product that can hurt you without touching you, a tool that moves soil with air, and the hardware that holds a tree together. It covers what the pesticide label obliges you to do and what your employer owes you before you first use one, mixing, storage and the water you wash in, air excavation around roots, and the pruning and cabling rules Z133 keeps for itself.
The final assessment
One exam, across everything.
Every module ends with a 10-question quiz. You need 80% to pass it, passing it opens the next module, and you can retake it straight away as often as you need. The final assessment is the only thing that gates the certificate: one exam drawn from all 7 modules, taken once you have finished them.
70% to pass, worked out from the number of questions. The exam is 90 questions, with at least one from every lesson. Allow about 90 minutes, a minute a question. Nothing times you.
You get 2 attempts with the course. Failing the first costs you nothing but a 6-hour wait, and your progress through the lessons is untouched — you retake the exam, never the course. The FAQ has the rest: the wait after each attempt, what you are shown about the questions you missed, and what happens if you use every attempt up.
The certificate
One sentence, and we do not stretch it.
It says that you completed the full course of instruction and passed the final assessment. That is the whole claim, and it is the same sentence on the PDF, on this page and on the verification page an employer lands on.
It carries your name, the date you passed, an expiry date 24 months later, and a code anybody can check without an account.
It is not a license, not a certification, and not accredited by anybody — and it is not a substitute for your employer watching you work. Hands-on competency is assessed on the ground by people who can see what you are doing, and no online course replaces that. If you are building a career as an arborist, board certification is the thing to pursue, and we will keep saying so.