OSHA, lockout/tagout and ANSI B11: what your CE file does not cover
You arrive with a complete technical file, a risk assessment to ISO 12100, a Performance Level calculation and a signed Declaration of Conformity. In an American plant, none of those documents is the one anyone asks for — and two American requirements will reach back into the machine’s design.
The first thing to understand is who is being regulated. OSHA has written it plainly: “OSHA regulates employers and does not regulate the products of manufacturers,” and “No portion of OSHA regulations are specifically directed to manufacturers.” More recently it added that it is not appropriate for OSHA to advise manufacturers on how to design machinery.
So nothing physical is federally required to accompany your machine. No mark, no declaration, no file to hand over. That is not a simplification — it is a transfer. Your customer answers personally for machine guarding and for hazardous energy control, and they pass the requirement back to you through the purchase specification, which is a document with no article numbers and no upper bound.
What this is not
One caveat we state because absolutes are how consultants get caught out: the rule is not literally without exception.
The power press provisions place an obligation on any person modifying a press to furnish instructions with the modification, and the hazardous energy rule is written in terms of machine design. Neither changes the general picture, and neither should be ignored.
Lockout/tagout: the one that changes your design
This is the requirement European builders are least prepared for, and it is not a procedural one.
OSHA defines an energy isolating device as a mechanical device that physically prevents the transmission or release of energy, and the definition ends with a sentence that decides a great deal of machine architecture:
“Push buttons, selector switches and other control circuit type devices are not energy isolating devices.”
29 CFR 1910.147(b)
OSHA’s own inspector training material makes the point with a case study titled Trusting the Limit Switch, concluding that a switch or other device in a control circuit is not an energy isolating device.
Read against European practice, that is a structural statement. The interlocked guards and safety-rated control functions that carry a European machine through maintenance access do not, by themselves, satisfy the American rule for servicing and maintenance. What is required is physical, lockable isolation — per energy source: electrical, pneumatic, hydraulic, gravitational, and stored energy in accumulators, springs and capacitors.
That is a design decision. Lockable isolation points, in accessible positions, one per energy source, with residual energy dissipation designed in — none of which can be retrofitted onto a machine already built without cutting into it.
Fact — check it yourself
Two genuine openings exist, and any consultant who tells you the rule is absolute has not read the standard.
Minor servicing integral to production can be handled with alternative measures which provide effective protection, and OSHA has accepted a safety PLC arrangement under those conditions following a system hazard analysis. Both are narrow, both have to be argued from the design, and both are worth arguing on a machine where physical isolation of every source would make the production cycle impossible.
29 CFR 1910.147(a)(2)(ii) note · OSHA letter of interpretation, 25 January 2008 (Wm. Wrigley Jr.)
And the procedure is your customer’s, not yours — but it is written from your documentation. OSHA does not require a separate written procedure for every machine: grouping is permitted for machines with the same type and magnitude of energy, same or similar controls, and the same sequential steps. There is an exemption from documenting the procedure, subject to eight cumulative conditions — but it exempts you from writing it down, not from having one and applying it. What you can supply is the energy source inventory, the isolation point map and the residual energy data that make the customer’s procedure writable at all. That is a deliverable, and most suppliers do not offer it.
Machine guarding: performance language, prescriptive surprises
The American general machine guarding rule is written in performance language and names no standard, no listing and no laboratory. There is no federal certification requirement for mechanical safety — the approval regime is essentially electrical.
That sounds permissive. In practice it means the requirement is assessed on the shop floor, against your customer, after the machine is running. And around it sit prescriptive requirements that do not exist in European practice at all — specific machine types carry their own detailed rules, including prescribed markings and label sizes, and there is at least one place where third-party validation is required for a mechanical safety system.
The gap this leaves is filled by the ANSI B11 series.
ANSI B11: what your ISO 12100 assessment is worth
The most useful sentence on this subject was written by the American standard about the European one. ANSI B11.0 states in its Foreword — a section that opens by declaring it is not part of the requirements — that:
“complying with the requirements of ISO 12100 will not assure compliance with the requirements of ANSI B11.0. Conversely, compliance with ANSI B11.0 will automatically result in compliance with the requirements of ISO 12100.”
ANSI B11.0-2020, Foreword
It gives its reasons. B11.0 addresses both the supplier and the end user of machinery, where ISO 12100 addresses only the supplier. And it covers existing, modified and rebuilt machinery, not only new machinery.
Be precise about what this is. It is a standards committee’s assessment of its own document, in a section that is explicitly not normative. It creates no presumption of conformity in Europe — that comes only from harmonised standards listed in the Official Journal. And B11.0 is voluntary in America: no federal rule makes it binding.
So why does it decide outcomes? Because a voluntary consensus standard is what a regulator reaches for when no specific rule covers a hazard, and what a plaintiff’s expert reaches for in court. OSHA has stated it may apply ANSI standards where no specific OSHA standard covers an electrical hazard. Your customer’s insurer thinks in these terms. So does their engineering department.
What has to be redone, concretely. Not the hazard identification — that work survives. What has to be rebuilt is the framing: a risk scoring structure of the kind B11.0 requires, documentation naming the assessment team and the validation with dates, retention tied to the life of the machine rather than a fixed term, and the residual risk formally transferred to the user with the tasks and hazards identified. The electrical design references change too: the American standard points at NFPA 79 and NFPA 70, not at IEC 60204-1.
What does not have to be redone. Your Performance Level or SIL calculation to ISO 13849-1 or IEC 62061 is cited as applicable, and NFPA 79’s informative annex points to the same standards. The functional safety work travels. ISO pictogram conventions are accepted as an alternative to the American signage standard.
What this is not
One thing we will not print, and the reason is instructive.
ANSI B11.0-2020 has been superseded by the 2023 edition, and no public preview of the 2023 text exists. We therefore quote the Foreword and cite no clause numbers. A consultant quoting clause numbers from a superseded edition on a compliance website is telling you something about their process.
And do not over-read what B11.0 says about responsibility. It allocates duties to the user where the supplier does not participate. That is a standard talking about standards. It does not move your product liability exposure in an American court, and nobody should tell you otherwise.
Robot cells
ANSI/RIA R15.06 is not made mandatory by any federal rule, and B11.0 presents it as one of several routes rather than the only one. Robot hazards are cited under general machine guarding, hazardous energy control or the general duty provision.
“Not mandatory” is not “ignorable”: it is the sector’s reference standard, and therefore what you will be measured against by OSHA, by your customer’s contract and by their insurer. Note also that the standard has been revised since B11.0-2020 — the secretariat is now A3, and the revision aligns with the current ISO robot safety standards. Anyone citing it without an edition year is citing from memory.
Fact — check it yourself
A useful counterweight to the pessimism on this page: OSHA’s own technical manual for its inspectors adopts the ISO 13849 framework for robotic systems, with required Performance Level, the Performance Level charts, and explicit references to ISO 13849-1 and 13849-2.
Your European functional safety work is not foreign to an American inspector. It is in their manual.
OSHA Technical Manual, Section IV, Chapter 4
What we do
- Energy source inventory and isolation point map, designed in rather than retrofitted, with the residual energy data your customer needs to write their procedure.
- Assessment of whether the alternative-measures route is available for the minor servicing your machine actually requires, and the system hazard analysis to support it.
- Conversion of your ISO 12100 risk assessment into the ANSI B11 framing: scoring structure, documentation fields, residual risk transfer to the user.
- Gap review against the machine-specific American requirements that apply to your machine type.
- The documentation package for the destination state, including the Ontario Pre-Start exemption file where Canada is in scope.