Links and resources
ICNIRP Guidelines on Limits of Exposure to Laser Radiation of Wavelengths Between 180 nm and 1,000 µm
The ICNIRP guidelines are from the International Commission on Non-Ionizing Radiation Protection. From the “Purpose and Scope”:
The purpose of these guidelines is to establish the maximum levels of exposure to laser radiation which are not expected to cause adverse biological effects to the eyes and the skin. The guidelines assist with the development of principles of protection against laser radiation hazards. Separate guidelines are defined for exposure to non-laser optical radiation (ICNIRP 1997, 2004, 2013).
The guidelines are intended for use by the various experts and national and international bodies who are responsible for developing regulations, recommendations, or codes of practice to protect workers and the general public from the potentially adverse effects of optical radiation.
The exposure limits listed apply to wavelengths from 180 nm - 1 mm and to exposure durations between 100 fs and 30 ks (about 8 h). The guidelines apply to all human exposure to optical radiation emitted by lasers. The exposure limits do not apply to deliberate exposure as an integral part of medical treatment. Due to the assumptions regarding pupil diameter and eye movements for deriving the retinal exposure limits, special considerations related to diagnostic exposures should be considered.
The guidelines apply to exposures to laser radiation producing acute onset of observable biological responses. In general there is a lack of knowledge regarding the injury threshold for effects from long term chronic exposure.
Injury thresholds are well defined for the effects that are in the scope of these guidelines. Therefore, in contrast to the ICNIRP guidelines for electromagnetic fields with wavelengths greater than 1 mm, the guidelines for optical radiation in general do not differentiate between workers and the general public.
Detailed measurement procedures and calculation methods are beyond the scope of this document and are provided elsewhere.
ANSI Z136 Standards
As of mid-2016, there are 9 ANSI Z136 standards covering laser safety topics. The only one needed for determining laser MPEs is Z136.1 - Safe Use of Lasers.
This page summarizes all 9 standards.
The ANSI standard is copyrighted; thus the standards must be purchased from (in the U.S.) the Laser Institute of America. The links above lead to the hardcopy or downloadable versions you can buy.
Online calculators
A calculator for determining the irradiance of a laser beam, given the following:
- Beam diameter at aperture
- Beam divergence
- Distance to the target point (for laser light shows, the closest access point of the audience)
- Laser power