Z133 Meeting Update 

The Z133 committee will meet via MS Teams on the second Tuesday every month from 9:00AM-12:00PM Central Standard Time as needed moving forward. The meetings will continue to be recorded.

The end-of-revision timeline is here. This timeline is subject to change.

The April 9, 2024 meeting has been cancelled. The next Z133 committee meeting will in-person on April 24, 2024.

If your contact information has changed, please complete this form.

Thank you for your support!

If you have any questions please contact Chericka Ashley at Z133@isa-arbor.com or call 678-367-0981 x226. 

    upcoming in-person Meeting  

There will be an in-person meeting held on

Wednesday, April 24, 2024.

    Hilton Baltimore BWI Airport Hotel in Baltimore, MD

Register for the meeting here.

Reserve your room here.     

What is the Z133?

This is an American National Standards Institute (ANSI) accredited standard which contains arboriculture safety requirements for pruning, repairing, maintaining, and removing trees; cutting brush; and for using equipment in such operations. 

Who creates it?

The standard is a collaborative effort of industry experts and representatives. The development of the standard is done under a five year revision cycle. Contributors consist of an Accredited Standards Committee (Voting Members), Task Chairs/Groups and interested parties.  The revision cycle also includes a public review period.

For a listing of current developers visit our Membership page.

The International Society of Arboriculture (ISA) acts as Secretariat for ANSI Z133. If you would like to contact ISA about a Z related question, please email us at Z133@isa-arbor.com.

Who needs it?

Employers engaged in pruning, repairing, maintaining, and removing trees; cutting brush; or performing pest or soil management related to tree care who hire one or more persons to perform such work. Other stakeholders would include contractors of such services and manufacturers and suppliers of equipment used in the provision of those services.

When is the Z133 revised?

The current revision is 2017 and a new Accredited Standards Committee is in place to begin the process for the 2024 revision.  

Want to know get a sense of how far we have come over the years? Check out the Evolution of the Z133!


The ANSI Z133 - 2017 is available in a digital format! Now you can access your copy of the Z133 right from your phone or tablet. 

To get your digital copy today, visit the ISA store.

Compatible with iOS and Android.

Licensing the Digital Z133 Safety Standard 

You can license the Z133 Safety Standard for your company. Use it for training purposes and more. 

Contact ISA for more information at Z133@isa-arbor.com

Spanish Z Now Available!

The ANSI Z133-2017 safety standard is now available in Spanish. Thank you to all the hard working volunteers who helped us complete this translation!

Purchase copies in the ISA store.


If you need assistance with an interpretation of a specific section of the Z133 Safety Standard, please click here to complete an Interpretation Request Form. Submit the completed form to Z133@isa-arbor.com