ISA Arborist Safety and Standards 2 — Questions and Answers

Question 1: What is the ANSI Z133 standard and what does it govern?

A voluntary design standard for tree houses and aerial platforms
The national consensus safety standard for arboricultural operations, covering personnel safety, equipment use, electrical hazards, and safe work practices for tree care (Correct answer)
A federal regulation requiring all tree workers to be ISA certified
A standard for manufacturing chainsaw safety equipment

Correct answer: The national consensus safety standard for arboricultural operations, covering personnel safety, equipment use, electrical hazards, and safe work practices for tree care

ANSI Z133 is the American National Standard for Arboricultural Operations - Safety Requirements. It establishes safety standards for tree care workers including climbing, rigging, electrical hazard management, chainsaw operation, and use of aerial devices.

ANSI Z133 is the primary safety standard for the arboricultural industry in the United States. Developed by the Accredited Standards Committee Z133 (which includes ISA, TCIA, OSHA, and other stakeholders), it establishes minimum safety requirements for arboricultural operations. Key areas covered include: general safety requirements (training, PPE, communication); electrical hazards (minimum approach distances, line-clearance qualifications); use of vehicles and mobile equipment; portable power tools and chainsaw operation; climbing, rigging, and work positioning; aerial devices (bucket trucks); and specific operation types (removal, pruning, cabling). While ANSI Z133 is a voluntary consensus standard, it carries significant legal weight — OSHA cites it as a recognized industry standard, and failure to follow it can establish negligence in legal proceedings. Many employers, municipalities, and client contracts require compliance with Z133.

Question 2: What are the OSHA requirements for training tree care workers regarding electrical hazards?

Only electricians need electrical hazard training
All tree workers must be trained to recognize and avoid electrical hazards; only qualified line-clearance arborists may work within the minimum approach distance of energized conductors (Correct answer)
Any tree worker may work near power lines if wearing rubber gloves
Electrical hazard training is optional in the tree care industry

Correct answer: All tree workers must be trained to recognize and avoid electrical hazards; only qualified line-clearance arborists may work within the minimum approach distance of energized conductors

OSHA requires all tree workers to be trained in electrical hazard recognition and avoidance. Only qualified line-clearance arborists (who receive extensive additional training) are permitted to work within the minimum approach distance of energized conductors.

Electrocution is consistently among the leading causes of death in the tree care industry. OSHA addresses this through multiple standards (29 CFR 1910.269 for utilities, 29 CFR 1910.331-335 for general industry). All tree workers must receive training to recognize electrical hazards and maintain safe distances from energized conductors. Non-qualified workers must remain at least 10 feet from conductors (more for voltages above 50 kV). Only qualified line-clearance arborists — who receive comprehensive training in electrical hazard recognition, safe work practices near energized conductors, first aid for electrical injuries, and CPR — may work within the minimum approach distance. Even qualified workers are not permitted to contact energized conductors. The utility company must be contacted for line de-energization, covering, or isolation when work requires closer proximity. Every pre-job briefing must include identification of all overhead and underground utilities.

Question 3: What documentation and training records should a tree care company maintain for each employee?

Only a signed employment contract
Training records for safety topics, equipment operation, first aid/CPR certifications, certification credentials, incident reports, and equipment inspection logs (Correct answer)
Only records of ISA certification
No documentation is required for tree care workers

Correct answer: Training records for safety topics, equipment operation, first aid/CPR certifications, certification credentials, incident reports, and equipment inspection logs

A responsible tree care company maintains comprehensive records: safety training (electrical hazards, chainsaw operation, aerial rescue), equipment operation authorizations, first aid/CPR certifications, professional credentials, incident/near-miss reports, and equipment inspection documentation.

Proper documentation is both a legal requirement and a best management practice for tree care companies. OSHA requires documentation of safety training, hazard communication, and injury/illness records (OSHA 300 log). ANSI Z133 references training requirements for specific operations. A thorough documentation program includes: new employee orientation and safety training (with dates, topics, and signatures); annual refresher training records; equipment-specific training and authorization (chainsaws, chippers, aerial devices, cranes); first aid and CPR certifications (current and accessible); ISA, TCIA, or other professional certifications; aerial rescue training (ANSI Z133 requires this for all climbers); vehicle operator qualifications; incident and near-miss reports (essential for safety program improvement); daily equipment inspection logs; and job hazard analysis records. This documentation demonstrates due diligence, supports insurance requirements, provides evidence of compliance during OSHA inspections, and serves as critical defense in litigation.

Question 4: What is the ISA's role in the tree care industry and how does ISA certification benefit practicing arborists?

ISA is a government regulatory agency that licenses arborists
ISA is an international professional organization that sets educational standards, administers certifications, conducts research, and advances the science of arboriculture — certification demonstrates competency and commitment to professional standards (Correct answer)
ISA only provides insurance for tree care companies
ISA certification is only relevant for academic researchers, not field arborists

Correct answer: ISA is an international professional organization that sets educational standards, administers certifications, conducts research, and advances the science of arboriculture — certification demonstrates competency and commitment to professional standards

ISA is a professional scientific and educational organization that promotes proper tree care through research, education, and certification programs. ISA Certified Arborist credential demonstrates knowledge competency, professional commitment, and adherence to industry standards.

The International Society of Arboriculture (ISA), founded in 1924, is the world's leading professional organization for arborists. ISA's mission includes: advancing the science and practice of arboriculture through research; developing and maintaining professional standards (ANSI A300, ISA Best Management Practices); administering certification programs (ISA Certified Arborist, Board Certified Master Arborist, Tree Risk Assessment Qualification, Municipal Specialist, Utility Specialist); providing continuing education through conferences, publications, and online resources; and advocating for proper tree care. ISA certification benefits arborists by: demonstrating verified knowledge to clients, employers, and the public; requiring continuing education (maintaining current knowledge); establishing credibility in legal proceedings; meeting contractual or municipal requirements; and supporting career advancement. ISA certification is recognized internationally but is not a government license — it is a voluntary professional credential that signifies competence and ethical commitment.

Question 5: What emergency response plan elements should be in place before beginning aerial tree work operations?

A phone number for the nearest hospital is sufficient
A written plan including aerial rescue procedures, first aid equipment location, emergency contact numbers, hospital route, communication protocols, and designation of trained rescue personnel (Correct answer)
Emergency plans are only needed for crane operations
The property owner is responsible for emergency planning, not the tree care company

Correct answer: A written plan including aerial rescue procedures, first aid equipment location, emergency contact numbers, hospital route, communication protocols, and designation of trained rescue personnel

Before any aerial work, the crew should have a comprehensive emergency plan: trained rescue personnel identified, aerial rescue procedure rehearsed, first aid kit accessible, emergency numbers posted, hospital/trauma center route known, and communication method established.

ANSI Z133 requires that an aerial rescue plan be in place whenever climbing operations are conducted. The plan must address: designated rescue personnel — at least one person on the ground crew must be trained and equipped to perform aerial rescue; rescue procedure — the specific method for reaching, securing, and lowering an injured or incapacitated climber; communication — how the climber will signal distress and how ground crew will communicate during rescue; first aid equipment — location and accessibility of first aid kit, AED if available, and any needed medication (EpiPen for known allergies); emergency contacts — phone numbers for 911, nearest trauma center, company emergency contact, and utility company (for electrical incidents); hospital route — pre-identified route to the nearest appropriate medical facility; and scene management — who contacts emergency services, who directs the ambulance to the site, and who secures the work zone. This plan should be reviewed during the tailboard safety briefing at the start of each job.

Question 6: According to industry standards, who is responsible for identifying underground utilities before tree work involving excavation?

The tree care company does not need to worry about underground utilities
The party performing the excavation work must contact 811 (or local one-call center) at least the required number of days before digging to have utilities located and marked (Correct answer)
Underground utilities are automatically detected by modern excavation equipment
Only the property owner can request utility locates

Correct answer: The party performing the excavation work must contact 811 (or local one-call center) at least the required number of days before digging to have utilities located and marked

Before any excavation (including stump grinding, root collar excavation, or planting), the 811 one-call system must be contacted to locate and mark underground utilities. This is legally required in all US states and prevents potentially fatal contact with buried gas, electric, or communication lines.

Underground utility contact is a serious and often underappreciated hazard in tree care operations. Stump grinding, root excavation (including air spade work), tree planting, soil remediation, and root barrier installation all involve subsurface disturbance. The 811 Call Before You Dig system is legally mandated in all 50 US states and most Canadian provinces. Calling 811 (typically 2-3 business days before work begins, depending on state law) triggers member utilities to send locators who mark the approximate location of buried gas, electric, water, sewer, cable, and telecommunications lines with color-coded paint or flags. This service is free. The tree care company is responsible for calling, regardless of who owns the property. Working without utility locates can result in: fatal electrocution from buried power lines, gas explosions, environmental contamination, service disruption, severe fines, and personal liability. Even air excavation can damage shallow utilities. The arborist should also be aware that private utility lines (from the meter to the house) may not be covered by the 811 system.

ISA Arborist Safety and Standards 2

What is the ANSI Z133 standard and what does it govern?