ANSI Z136 Requirements and Test Procedures for the Safe Use of Lasers

The ANSI Z136 series of standards, developed by the American National Standards Institute (ANSI), includes requirements and test procedures for the safe use of lasers.

“ANSI Z136.1 American National Standard for the Safe Use of Lasers” is the fundamental horizontal standard. Laser safety programs provide general requirements on hazard assessment, classification (Class 1, 1M, 2, 2M, 3R, 3B, 4), maximum allowable exposure, control measures, non-radiation hazards, and similar issues. All other ANSI Z136 standards refer to or are based on this section.

Other ANSI Z136 standards are specialized (vertical) standards. These apply to specific environments or applications and generally take precedence over the ANSI Z136.1 standard within their particular scope.

The ANSI Z136 standard consists of the following sub-sections:

• The ANSI Z136.1 “Safe handling of lasers” standard describes recommended guidelines for the safe handling of lasers operating at wavelengths between 180 nm and 1000 μm. This standard specifies the environment in which the laser is used and the environment surrounding the beam path.

Today, laser technology is widely used in industries all over the world. While the possibility of material damage in laser processes is an important consideration, the main concern is the danger to anyone operating the equipment.

The ANSI Z136.1 standard provides comprehensive recommendations for the safe use of lasers and laser systems operating at wavelengths between 180 nm and 1000 μm (1 mm). While focusing on protecting people from hazards associated with laser radiation, it also addresses non-radiation hazards.

This standard applies to industrial, medical, research, educational, military, and outdoor laser applications. It is widely recognized by OSHA and serves as the de facto benchmark for laser safety programs.

One of the most important contributions of this standard is the seven-class laser classification system based on the potential of the laser to cause biological damage to the eye or skin:

• Class 1 is safe under all normal conditions (no danger).
• Class 1M is safe unless viewed with optical instruments (e.g., magnifying glasses).
• Class 2 visible lasers generally protect the eye through an avoidance response (blinking reflex).
• Class 2M is the same as Class 2, but is dangerous when viewed with optical instruments.
• Class 3R: Low risk of injury from direct gaze, small risk of eye injury.
• Class 3B: Vision through direct or specular reflection is dangerous; diffuse reflections are generally safe.
• Class 4 lasers are high-powered lasers that can cause eye and skin injury, fire hazards, and dangerous scattered reflections.

This classification categorizes each type of laser according to its potential to cause biological harm. Class 1 lasers are exempt from all controls as they pose no hazard, while Class 4 lasers require rigorous controls to reduce the risk of eye or skin exposure. Specific controls for each classification are detailed in the standard.

• The ANSI Z136.2 standard, “Safe handling of optical fiber communication systems using laser diode and LED sources,” provides guidance for the safe handling, maintenance, servicing, and installation of optical communication systems using laser diodes or light-emitting diodes operating at wavelengths between 0,6 mm and 1 mm.

Optical communication systems include end-to-end optical fiber-based links, fixed terrestrial point-to-point free-space links, or a combination of both. This standard is designed for use by those installing end-to-end systems and by service, maintenance, and other personnel who may interact with these systems in situations where access is uncontrolled, controlled, or restricted. It provides detailed safety information for systems where optical energy is accessible and source parameters are uncertain or not under user control.

This standard includes control measures appropriate to the specific hazard level (optical fiber connections) and access level (free-space connections). Most assessments can be performed analytically, and a number of representative hazard assessment examples are given in the appendices.

This standard addresses two main types of systems:

• Fiber optic communication systems: End-to-end fiber-based connections.
• Free-space optical communication systems: Fixed terrestrial point-to-point links (or hybrid systems combining both).

Unlike conventional lasers, fiber optic systems are generally enclosed and operate as Class 1 (inherently safe) under normal conditions. However, hazards arise during servicing, maintenance, installation, or when the fibers are disconnected (when accessible optical radiation is present).

Fiber optic networks are growing rapidly. Technicians frequently work with live or potentially energized fibers in uncontrolled environments. The ANSI Z136.2 standard helps prevent eye injuries from invisible infrared laser radiation, which is a real risk during splicing or testing.

• The ANSI Z136.3 “Safe use of lasers in healthcare” standard provides guidance for lasers in healthcare and applies to lasers (laser radiation) operating at wavelengths between 180 nm and 1000 µm in the UV, visible, and IR regions of the electromagnetic spectrum. It provides specific procedures to protect anyone who may be exposed to laser radiation and helps establish a program to promote the safe use of laser systems in healthcare.

This standard applies to all settings where a laser used in healthcare laser systems is used as a medical device. This includes hospital facilities, outpatient surgical centers, and individual medical, dental, and veterinary offices, as well as non-medical settings such as salons and spas.

Healthcare laser systems include a distribution system to direct the laser output, a power supply with laser controls and calibrations, a protective housing, and associated fluids and gases.

Medical lasers are used in thousands of procedures every day. Hazards include eye injury, skin burns, surgical fires, inhalation of laser fumes (which may contain viruses and carcinogens), and electrical risks. This standard helps facilities prevent these incidents through structured controls, training, and supervision.

This standard is the gold standard for laser safety in the healthcare sector. Compliance with this standard protects patients and staff, reduces liability risks, and ensures the safe and effective use of medical lasers.

• The ANSI Z136.4 Laser safety measurements standard provides guidance for optical measurements related to laser safety requirements. Optical measurements refer to the examination of the intensity, spectral distribution, polarization, or other properties of light emitted from or reflected by an object or passing through a medium. This standard specifies that for a successful optical measurement, the beam must be correctly aligned with each element in its path, including apertures, lenses, wedges, filters, mirrors, beam dampers, and detectors.

Furthermore, this standard specifically addresses the measurement of parameters related to the laser output beam necessary to obtain values ​​for quantities used in classification or hazard assessment calculations. The assessment consists of comparing the measured exposures with the maximum allowable exposure values ​​specified in the ANSI Z136.1 standard, based on the ability of the direct, reflected, or scattered laser beam to cause biological damage to the eye or skin.

This standard provides detailed guidance on how to perform optical measurements of laser beams, which are necessary for assessing hazards and classifying lasers according to the ANSI Z136.1 standard. It covers the measurements required to determine the following basic parameters:

• Power or energy output
• Radiation intensity or radiation exposure
• Beam diameter and deflection
• Pulse characteristics (for pulsed lasers)
• Wavelength and spectral distribution

These measurements are necessary for the following:

• Determining the correct laser classification.
• Calculating the maximum permissible exposure levels.
• Defining the nominal hazard zone.
• Assessment of achievable emission limits.

This standard applies to lasers operating between 180 nm and 1 mm (UV to far infrared).

This standard provides the technical basis for accurate laser hazard assessment. While more specific and measurement-focused than other Z136 standards, it is indispensable for anyone wishing to classify lasers, calculate nominal hazard zones, or reliably verify safety controls. The correct application of this recommended practice helps bridge the gap between theoretical safety limits and real-world laser performance.

• The ANSI Z136.5 “Safe Use of Lasers in Educational Institutions” standard addresses laser safety concerns and situations that may arise in educational settings. This standard does not replace the ANSI Z136.1 standard, which is necessary for a complete understanding of laser safety officer duties and laser hazard assessment. Educational settings where lasers may be present include teaching laboratories, classrooms, lecture halls, science fairs, museums, and on-campus and off-campus student projects. This standard is designed for faculty and students using lasers at the elementary, secondary, and university levels, excluding graduate research laboratories. The wavelength range of interest includes the ultraviolet (UV), visible, and infrared (IR) regions of the electromagnetic spectrum, specifically the wavelength range between 180 nanometers (nm) and 1 millimeter (mm).

In short, this standard addresses laser safety concerns specific to teaching and demonstration settings. It covers the safe use of lasers and laser systems in classrooms, laboratories, science fairs, and school demonstrations, and particularly emphasizes the following:

• Student safety
• Teacher training
• Simplified control measures to suit educational budgets and environments.
• Preventing injuries while promoting hands-on learning with lasers.

This standard applies to lasers operating between 180 nm and 1 mm and primarily focuses on low- to medium-power lasers (Class 1, 2, 3R and some Class 3B) commonly used in education.

• The ANSI Z136.6 “Safe Use of Lasers in Outdoor Areas” standard specifies guidelines for designers, users, and operators of lasers or laser systems for outdoor use, and has numerous applications including laser light shows, lasers used in outdoor scientific research, and military lasers.

One of the most significant concerns regarding the outdoor use of light-stimulated emission methods is that laser beams can travel freely without being blocked by the same barriers that hinder laser dispersion indoors. Diffraction of the laser beam can cause it to spread over longer distances, posing a danger to a larger number of people. This standard also addresses atmospheric effects that can alter lasers when used only outdoors. For example, scintillation caused by temperature changes leads to alterations in the energy distribution of the beam, while attenuation caused by aerosols changes the wavelength of the beams.

This standard addresses the unique challenges of outdoor laser use, where factors such as long atmospheric propagation, unpredictable public access, weather conditions, and aviation concerns significantly increase the risk. This standard covers lasers operating between 180 nm and 1 mm (UV to far infrared).

The main application areas are:

• Laser light shows and entertainment screens
• Construction, surveying and alignment
• Scientific research (e.g., atmospheric LIDAR, astronomy)
• Military and defense applications
• Outdoor communication and range determination.
• Free field optical systems

This standard emphasizes protecting not only operators but also the general public, aircraft, and sensitive receivers (e.g., observatories).

Outdoor lasers can pose a danger over very long distances. A high-powered Class 4 laser can be dangerous for kilometers. Common risks include:

• Eye injuries to civilians or pilots
• Distraction or temporary blindness experienced by the aircraft crew
• Damage to sensitive optical equipment (e.g., astronomical telescopes)

This standard helps organizations implement proportionate controls while enabling valuable outdoor laser applications. It is particularly important for laser show producers who must comply with this standard and FAA regulations for airspace permits.

• The ANSI Z136.7 Testing of Laser Protective Equipment standard provides recommendations for testing and labeling laser protective materials and protective equipment, such as eye protectors, barriers, curtains, filters, and windows, designed for use with lasers and laser systems operating at wavelengths between 180 nm and 106 nm. Given that the human eye is now widely accepted to be almost always more vulnerable to injury than human skin, ensuring adequate testing of laser protective eyewear (e.g., absorbing, interfering/reflective, and hybrid filter technologies) is of paramount importance.

This standard provides test procedures to ensure that laser protective materials and equipment maintain their specified level of protection throughout the product's lifespan. These protective devices include laser eye protection devices or instrument filters, laser window filters, and laser field protection barriers, screens, or beam-blocking curtains. Different test methods may be required depending on the protective device, laser type, transient operating mode, and wavelength(s). This standard aims to provide reasonable and adequate guidance on test methods, protocols, and specifications for devices used to provide eye protection from lasers and laser systems.

In short, this standard provides manufacturers, testing laboratories, and users with clear recommendations for the evaluation and labeling of laser protective materials and equipment. This standard covers the following:

• Laser protective glasses
• Barriers and curtains
• Windows and filters
• Other protective materials

This standard applies to lasers operating between 180 nm and 1000 μm. It emphasizes rigorous testing to ensure the equipment maintains the specified level of protection throughout its service life. Key limitations of this standard include:

• Personal protective equipment is not covered for high-energy lasers with an optical density greater than 7.
• It may not be sufficient for extremely high pulse or very high continuous wave power lasers.

This standard plays a vital role in the laser safety ecosystem by ensuring that protective equipment is reliably tested and clearly labeled. In an era of increasingly powerful and diverse laser applications, this standard helps maintain confidence in equipment that protects the eyes, the body's most vulnerable part.

• The ANSI Z136.8 “Safe use of lasers in research and testing” standard provides guidance and recommendations to users for the safe use of lasers and laser systems primarily used for research, development, or testing in indoor environments. It applies to lasers/laser systems operating between 180 nm ultraviolet (UV) and 1000 μm infrared (IR) wavelengths.

Test environments may deviate from normal laser operations and may require access to laser radiation levels higher than the achievable emission limits for the assigned laser class. Bearing these considerations in mind, safety is ensured primarily by classifying lasers according to their relative hazards and then determining control measures based on these hazards and operating conditions.

This standard addresses challenges that differ from those in industrial or clinical settings:

• Frequent changes in experimental setups
• Open ray paths
• Custom or home-made laser systems
• Temporary or evolving configurations
• High-power or new laser technologies

This standard is primarily applicable to indoor environments, but also includes provisions for controlled outdoor experiments. It is based on and complements the ANSI Z136.1 standard, while also offering more flexible and practical approaches suitable for R&D.

Research laboratories frequently use 3D and Class 4 lasers in non-routine configurations. Common risks include eye exposure during alignment, unexpected beam reflections, and inadequate controls in modified systems. This standard helps organizations balance cutting-edge research with safety by providing realistic and adaptable requirements. This standard is widely used by:

• University physics, chemistry and engineering departments
• National laboratories
• Dedicated R&D facilities
• State research institutions

This standard provides practical, industry-specific guidance for the safe use of lasers and laser systems in manufacturing and industrial settings. This standard covers lasers with wavelengths between 180 nm and 1 mm² (UV to far infrared) used in processes such as the following:

• Material processing (cutting, welding, drilling, marking, engraving)
• Laser alignment, leveling, and metrology.
• Manufacturing and assembly
• Machine vision and control
• Inventory control and automated systems

This standard addresses the unique challenges of manufacturing environments, including high-volume production, automated machinery, integration with robotic systems, and the presence of non-laser industrial hazards.

This standard remains the fundamental reference for laser safety in the manufacturing sector. It translates the broad principles of laser safety into practical, production-oriented requirements that support both worker protection and efficient operations. For any facility using lasers in industrial processing or automation, this standard is an indispensable tool for establishing a robust and compliant laser safety program. The guidance of this standard remains highly relevant for modern smart factories and advanced manufacturing.

• “ANSI Z136.910 Safe use of lasers in entertainment, display and exhibition areas” is the newest standard planned in the laser safety series. Unlike other published standards in the series, this standard has not yet been released as a final standard and is still under development. This standard aims to provide practical, application-specific guidance for the safe use of lasers and laser systems in the following areas:
  • Laser light shows and entertainment productions
  • Architectural and artistic exhibitions
  • Trade fairs, exhibitions and promotional events
  • Themed venues, nightclubs, concerts, and festivals.
  • Outdoor and indoor display applications

This standard addresses the unique challenges of the following environments:

• Dynamic, moving rays and scanned patterns
• Large crowds (often untrained in laser safety)
• Temporary installations and frequent equipment changes.
• Music interacts with fog, haze, and stage effects.
• Coordination with venue staff, performers and authorities (e.g. FAA for outdoor performances)

This standard covers lasers operating between 180 nm and 1 mm, and focuses specifically on Class 3B and Class 4 lasers, which are widely used in the entertainment industry.

This standard serves as a much-needed, specialized guide for the safe and creative use of lasers in shows and exhibitions.

For many years, our organization, with its competent and experienced team, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services compliant with ANSI Z136 standards.