Welcome to the standards main page. TCIA actively participates in the development of performance standards for the professional arborist. Arborists who adhere to industry standards of practice are more professional than those who do not. In the arborist industry in the U.S., there are two voluntary standards related to arborists' activities: The ANSI A300 Standard and the ANSI Z133 Standard. ANSI stands for American National Standards Institute, the accrediting organization for the committees that write the standards.

There are currently six ANSI A300 standards - for pruning, cabling and bracing, tree fertilization, lightning protection, management of trees and shrubs, and transplanting. A seventh, Integrated Vegetation Management, is in the works. The A300 Standards were developed so arborists and plant maintenance managers can write accurate work specifications that follow accepted tree care industry practices. With written work specifications you can compare "apples to apples."

Arborists should include pruning specifications as part of their estimates and/or contracts. In this way, professional tree care companies can provide clients a way to compare one bid to another, giving reputable businesses protection from dishonest competitors. Property managers can put work out to bid with specifications already included or can require that work specifications be included in the bid. In this way the manager insures that accepted tree care practices are followed, and is able to objectively compare bids from different companies. The ANSI Z133 Standard contains safe work practices for virtually all arborists' activities. It should be the guiding document that the arborist uses in all aspects of his/her work. Although it is a voluntary standard, it can carry the weight of law.

If you have any questions about government standards and tree care operations, please send an email to our senior safety advisor or standards expert.