This is a sizeable expansion on the topic from the previous version, and specifically details the safety requirements of each of these tree worker positions. One of the most notable changes is in section 4 – Electrical Hazards – specifically the expansion of the rules for working in proximity to electrical hazards to recognize three levels of qualification: the unqualified, the Incidental Line Clearance Arborist and Utility Line Clearance Arborist. The following are a small selection of changes in the 2017 revision: Electrical hazards When OSHA cannot find language in its own standards to guide safe work practices in a particular situation they will typically cite a section of Z133 as what the employer "should have known or done” to create a safe work environment for its employees. This revision provides the most current and comprehensive safety guidance for arborists in the United States.Īlthough compliance with this standard is voluntary, Z133 carries the force of law in many instances in the U.S. The Z133 is developed by the Accredited Standards Committee ASC Z133. The American National Standard for Arboricultural Operations - Safety Requirements, also known as the ANSI Z133 or just Z133, recently completed its 2017 revision. TCIA members get a 25% discount and pay only $15.00. To fully familiarize yourself with the revisions, we recommend picking up a copy, currently available in the TCIA Shop. These are just a few of the revisions in the updated Z133.