What ANSI/A3 R15.06-2025 Means for Robot Cell Design

Industrial robot safety in the United States is built on ANSI/A3 R15.06, the national standard for industrial robots and robot systems. The 2025 edition adopts the international standards ISO 10218-1:2025 and ISO 10218-2:2025 as the American National Standard. For anyone designing, integrating or buying a robot cell, it is the reference for how safety should be approached.

This is a plain-language overview. It does not replace the standards, which should be purchased and read in full, or qualified safety engineering.

Three parts, three responsibilities

Part 1 (ISO 10218-1) covers industrial robots. Written primarily for robot manufacturers, it sets design requirements for the robot as a component: protective stops, speed and force limits, control behavior and the safety functions a robot must provide.

Part 2 (ISO 10218-2) covers industrial robot applications and robot cells. It governs how a robot is combined with tooling, external axes, guarding, sensors and other equipment into a safe application.

Part 3 (ANSI/A3 R15.06-3-2025) covers the use of industrial robot cells: guidance for the users who operate and maintain a cell safely day to day.

A welding cell builder answers to the first two: the arm must meet Part 1 and the integrated cell must meet Part 2. The yard running the cell works under Part 3.

Risk assessment comes first

The standard does not prescribe one design. It requires the designer to identify hazards, estimate the risk of each and reduce it to an acceptable level.

In a welding cell the hazards go well beyond robot motion: arc radiation, fumes, heat, spatter, electrical hazards, moving rails and positioners, and the handling of heavy parts. Each is evaluated against how people actually interact with the cell: loading parts, changing consumables, inspecting welds, maintenance and troubleshooting.

Safeguarding

Once hazards are identified, risk is reduced in order: eliminate hazards by design where possible, then add safeguarding, then provide information and training. Common safeguards include fixed guards, interlocked doors, light curtains, safety laser scanners and safety-rated functions such as speed and separation monitoring, safe zones and limited speed.

Large-structure cells make this harder. A rail cell may run many meters and stay open on several sides so cranes can deliver parts. Designers have to work out where people can be and how the system detects them.

Functional safety

Safety functions that protect people have to be reliable. The standard draws on functional safety requirements that set how robust each function must be for the risk it addresses. In practice that often means safety-rated controllers, redundant sensing and monitored stops.

This is why Catfish separates planning from safety. Planning software proposes motion, deterministic control executes it within configured limits, and an independent safety controller can stop or inhibit motion.

Collaborative applications

The 2025 editions handle collaborative-application safety requirements within the main framework, with the emphasis on the application rather than the robot. A robot is not "safe" on its own; whether a collaborative application is acceptable depends on the risk assessment for that specific use.

What it means for a buyer

For a shipyard considering robotic welding:

• Ask how the cell's risk assessment was done and who owns it.
• Expect safeguarding that fits your real operations, including crane loading and maintenance.
• Find out which safety functions run in safety-rated hardware.
• Make training and documentation part of the delivery.

Every Catfish cell uses an installation-specific industrial safety architecture informed by the site risk assessment, with safety validation completed together with the customer.

R15.06-2025 brings the U.S. in line with the 2025 ISO 10218 standards, and its core message has not changed: safety comes from a structured risk assessment and safeguarding applied to the whole application. For large cells with many moving axes, that discipline shapes every design decision.

References to standards are educational and do not indicate Catfish certification.