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Tree care safety standards, made simple
What ANSI Z133, ANSI A300 and OSHA are, how they differ, and why it helps to say honestly that your crews follow them. This is general information, not legal advice.
Last reviewed: October 2026. Lirevon is not affiliated with these organizations.
ANSI Z133: safety requirements for arboricultural operations
ANSI Z133 is a voluntary US safety standard for tree care work. It covers how crews should work safely, for example around climbing, rigging, chain saws, chippers, aerial lifts and electrical hazards. Think of it as a written set of safe-work rules for the industry.
ANSI stands for the American National Standards Institute, which approves the process used to develop standards like this one. The standard is updated from time to time, so check that you are reading the current edition.
ANSI A300: tree care performance standards
ANSI A300 is a set of standards for how tree care work should be done, such as pruning, planting, fertilizing and tree support. Where Z133 is about keeping people safe, A300 is about the quality and method of the work done on the tree.
The TCIA is closely involved with the A300 standards. Many tree care professionals use A300 as the common language for writing work proposals, for example describing what kind of pruning a customer is buying.
OSHA: the government safety agency
OSHA is the Occupational Safety and Health Administration, part of the US Department of Labor. It sets and enforces workplace safety rules for many employers, and tree care companies with employees can be covered.
OSHA and the ANSI standards are not the same thing. OSHA rules are set by the government. ANSI standards are voluntary consensus standards, though they are often used as a reference for what safe practice looks like. Rules can differ by state, so ask OSHA or a qualified professional what applies to you.
Why this matters in marketing
Homeowners cannot judge rigging or climbing on their own, so they look for signs of a careful company. A short, honest line such as "our crews are trained to follow ANSI Z133 and A300 practices" gives them a reason to trust you, and gives search and AI tools a clear fact to quote.
Only say what is true for your company. Do not say "OSHA approved" or "fully compliant" unless you have checked what that means for you. Put the line on your about page, service pages and Google Business Profile description. This page is general information and not legal advice. Ask a lawyer or safety professional about your own duties.
Common questions
What is ANSI Z133 in simple words?
It is a written set of safety rules for tree care work, covering things like climbing, chain saws, chippers and working near power lines. It is voluntary, and the industry uses it as a guide to safe practice.
What is the difference between Z133 and A300?
Z133 is about safety for the crew. A300 is about how tree work should be done, such as pruning methods. A good company can follow both.
Is OSHA the same as ANSI?
No. OSHA is a government agency that enforces workplace rules. ANSI approves the process for developing consensus standards, which are voluntary unless a law or contract requires them.
Can I say my company follows ANSI standards?
Only if it is true and your crew is actually trained in them. Use plain words and avoid broad claims like "fully compliant." When unsure, ask a safety professional.
Does following these standards make a job risk-free?
No. Tree work is dangerous. Standards help lower risk, but they do not remove it. Do not promise a customer a risk-free job.
Is this page legal advice?
No. It is general information to help you understand terms. For your legal duties, talk to a qualified lawyer or safety professional.
This page is general information, not legal advice. Check each organization's own website for current details.
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