Laser Safety Note: Warning lights are only one component of a laser safety program. The appropriate controls depend on the laser classification, application, Nominal Hazard Zone (NHZ), facility layout, entryway-control method, and the evaluation of the Laser Safety Officer (LSO). Always consult your on-site LSO when determining appropriate controls for a laser controlled area.
A laser safety barrier or curtain helps control where potentially hazardous laser radiation can travel. But containment is only part of controlling access to a laser area.
People approaching the area also need to understand whether the laser is operating or may be about to operate.
That is where a laser area warning light can be useful.
Laser Safety Industries offers two basic warning-light approaches with our laser barrier and curtain systems:
Manual Laser Status Warning Light — a plug-and-play option controlled by the operator.
Machine-Integrated Laser Warning Light — a 24V industrial light designed to receive its status directly from the laser, PLC, or machine control system.
Neither option should be viewed as automatically making an installation “ANSI compliant.” The warning light needs to be selected and implemented as part of the facility's overall laser safety controls.
What Does ANSI Say About Laser Area Warning Devices?
For manufacturing environments, ANSI Z136.9-2013, Safe Use of Lasers in Manufacturing Environments, remains the current published edition as of 2026. ANSI is currently working on a future revision.
Section 4.4.2.8, Area Warning Device, addresses informing people who are about to enter a Class 3B or Class 4 laser controlled area that laser radiation is being emitted or may soon be emitted.
Section 4.4.2.8.1, Visible Warning Device, describes a visible device that may be a single lamp or an illuminated/flashing laser warning sign. Importantly, the standard says the device should be electrically interfaced with the laser power supply so its indication corresponds with laser operation.
The word “should” matters. In ANSI terminology, it is a recommendation rather than the mandatory “shall.”
That distinction is one reason there can be applications for both manually operated and automatically controlled warning lights.
OSHA's current Laser Safety Technical Manual also discusses warning lights as part of Class IV laser-area controls. For procedural entryway controls, OSHA describes a warning light or sound outside the entryway that operates when the laser is energized and operating. It also describes multi-state warning systems that can communicate whether a laser is off, energized, or actively operating.
Option 1: Manual Laser Status Warning Light
A manual warning light is the simpler option.
Instead of being connected to the laser or PLC, the operator controls the status of the light manually.
The unit we offer is a plug-and-play system with a separate operator control box connected to the warning light. This avoids the need for the customer to design a 24V control circuit simply to operate the indicator.
When does a manual warning light make sense?
A manual system may be appropriate when:
The laser does not have an easily accessible PLC or control output.
The facility is relying heavily on administrative or procedural controls.
The warning light is intended primarily to provide an additional visual indication to personnel.
A portable or temporary laser barrier system is being used.
Automatic integration is not practical for the application.
The important limitation is straightforward:
The light does not know whether the laser is actually operating.
The operator is responsible for changing its status as part of the facility's procedure.
Because of that, a manually operated warning light does not provide the same automatic relationship between the warning indication and the laser's operating state as an electrically interfaced system.
Manual Laser Status Warning Light
LSI Price: $395
Designed as a straightforward, plug-and-play warning-light option for laser controlled areas. This is our standard manual warning-light configuration and does not require integration with the laser or machine controls.
For customers looking for additional configurations or options—including audible alerts, different mounting arrangements, cable lengths, or other customizations—we recommend working directly with the manufacturer.
View Manual Warning Light Details & Customization Options →
Configure through Stack-Light
Option 2: Machine-Integrated Laser Warning Light
For industrial laser systems, robotic cells, laser welding equipment, and other automated manufacturing environments, a machine-integrated warning light will often be the more appropriate approach.
Our standard machine-integrated warning light is a 24V industrial LED stack light intended to be connected to the customer's laser, PLC, or machine controls.
The unit supports multiple independently controlled light levels, flashing operation, and an integrated audible alarm. The manufacturer specifies 24V DC operation, an 85 dB built-in buzzer, and configurations with one to five light levels.
Our standard laser configuration
For laser applications, we recommend a three-level configuration:
Green — Laser Not Enabled / Area Status Safe
Amber — Laser Enabled / Standby
Red — Laser Operating / Hazard Status
These descriptions are an example configuration and should be matched to the actual signals available from the laser or machine.
The facility's LSO and machine integrator should determine exactly what each state means for the particular installation.
Why integrate the warning light?
The major advantage is that the operator does not have to remember to change the warning light.
For example, the machine controls could be configured so:
Laser disabled → Green
Laser enabled → Amber
Laser emitting → Red or flashing Red
That creates a direct relationship between the condition of the laser system and the information presented to someone approaching the controlled area.
It also more directly follows the ANSI Z136.9 recommendation that a visible warning device be electrically interfaced and controlled by the laser system.
Machine-Integrated Laser Warning Light
LSI Price: $175
24V warning-light system designed for connection to a laser, PLC, or machine control system.
View Additional Colors, Mounting & Configuration Options →
Machine-integrated warning light configurator
Installation note: Electrical integration is performed by the customer or machine integrator. Laser Safety Industries does not configure the customer's laser or PLC controls.
Which Laser Warning Light Should I Choose?
For most customers, the decision comes down to one question:
Can the warning light receive a signal directly from the laser or machine controls?
If yes, we generally recommend considering the Machine-Integrated Laser Warning Light.
If no, or if the application is intentionally using a procedural/manual approach, the Manual Laser Status Warning Light provides a straightforward visual indicator without requiring machine integration.
| Manual | Machine Integrated |
Plug-and-play | Yes | No |
Operator controlled | Yes | No |
Laser/PLC controlled | No | Yes |
24V machine integration required | No | Yes |
Good for portable systems | Yes | Depends on application |
Automatically follows machine state | No | Yes |
LSI Price | $395 | $175 |
Does a Warning Light Replace a Laser Warning Sign?
No.
A visual status light and a laser warning sign serve different purposes.
A warning light communicates a changing operating condition. A laser warning sign identifies the area and communicates the laser hazard and required precautions.
OSHA's laser-safety guidance separately discusses appropriate area posting and Class IV activation-warning systems.
Depending on the application, an entrance to a laser controlled area may therefore include both:
Laser Warning Sign + Laser Area Warning Light + Appropriate Physical Containment
The specific requirements should be established through the facility's laser hazard evaluation and LSO.
Adding a Warning Light to an LSI Laser Barrier or Curtain
Laser Area Warning Lights are available as optional accessories on Laser Safety Industries barrier and curtain systems.
When configuring your system, select:
No Warning Light
Manual Laser Status Warning Light
or
Machine-Integrated Laser Warning Light
Customers requiring different colors, mounting arrangements, additional light levels, or specialized controls can also configure additional options through the manufacturer's product configurator.
If you are unsure whether a manual or machine-integrated warning device is appropriate for your application, contact Laser Safety Industries to discuss the barrier system, laser application, and available control signals.