IEC TR 60825-14:2004

TECHNICAL IEC
REPORT TR 60825-14
First edition
2004-02
Safety of laser products –
Part 14:
A user's guide
Reference number
IEC/TR 60825-14:2004(E)
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TECHNICAL IEC
REPORT TR 60825-14
First edition
2004-02
Safety of laser products –
Part 14:
A user's guide
 IEC 2004  Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
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– 2 – TR 60825-14  IEC:2004(E)
CONTENTS
FOREWORD.4
INTRODUCTION.6
1 Scope and object.7
2 Terms and definitions .8
3 Administrative policies.16
3.1 Safety responsibilities.16
3.2 Competent persons.17
3.3 Laser Safety Officer .17
3.4 Information and training.18
4 Laser radiation hazards .19
4.1 Laser products.19
4.2 Exposure to laser radiation.23
4.3 Determining the level of laser exposure.23
5 Determining the maximum permissible exposure (MPE) .28
5.1 General remarks.28
5.2 Repetitively pulsed or modulated lasers .28
5.3 Multiple wavelengths.29
5.4 Extended source MPEs.30
5.5 Hazard distance and hazard area .30
6 Associated hazards.31
6.1 Additional health hazards .31
6.2 Hazards arising from the laser.32
6.3 Hazards arising from the environment .33
6.4 Control of associated hazards .34
7 Evaluating risk.35
7.1 Hazards and risks.35
7.2 Risk assessment: Stage 1 – Identifying potentially injurious situations. .35
7.3 Risk assessment: Stage 2 – Assessing risk for potentially injurious situations. .36
7.4 Risk assessment: Stage 3 – Selecting control measures .38
8 Control measures.38
8.1 General.38
8.2 Hazard reduction.39
8.3 Enclosing the hazard.39
8.4 Hazard mitigation.41
8.5 Equipment servicing.46
9 Maintenance of safe operation.47
10 Incident reporting and accident investigation .48
11 Medical surveillance.48

Annex A (informative) Examples of interlock systems for laser controlled areas.54
Annex B (informative) Examples of calculations .59
Annex C (informative) Biophysical considerations .82

Bibliography.92

TR 60825-14  IEC:2004(E) – 3 –

Figure 1 – Laser hazard symbol.18
Figure 2a – Measurement set-up using a lens.26
Figure 2b – Direct measurement set-up .27
Figure 2 – Measurement set-ups.27
Figure A.1 – Purpose of an interlock system .56
Figure A.2 – Non-locking interlock system .57
Figure A.3 – Locking interlock system.58
Figure B.1 – Laser diode array with two groupings.76
Figure C.1 – Anatomy of the eye.89
Figure C.2 – Diagram of laser-induced damage in biological systems .90

Table 1 – Default protective control measures for laser products .21
Table 2 – The diameter of the limiting aperture applicable to measurements of
irradiance and radiant exposure (t is the exposure duration) .25
Table 3 – Duration T below which pulse groups are summed up .29
i
Table 4 – Additivity of effects on eye (O) and skin (S) of radiation of different spectral
regions .30
Table 5 – Maximum permissible exposure (MPE) at the cornea for direct exposure to
laser radiation.49
Table 6 – Maximum permissible exposure (MPE) at the cornea for direct exposure to
laser radiation from extended sources in the wavelength range from 400 nm to
1400 nm (retinal hazard region) .50
Table 7 – Maximum permissible exposure (MPE) of skin to laser radiation.51
Table 8 – Correction factors for MPEs .52
Table 9 – Laser controlled areas.53
Table C.1 – Summary of pathological effects associated with excessive exposure to light .84
Table C.2 – Explanation of measurement apertures applied to the MPEs.88

– 4 – TR 60825-14  IEC:2004(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SAFETY OF LASER PRODUCTS –
Part 14: A user's guide
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
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with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
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transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a technical report when it has collected
data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
IEC 60825-14, which is a technical report, has been prepared by IEC technical committee 76:
Optical radiation safety and laser equipment.
The text of this technical report is based on the following documents:
Enquiry draft Report on voting
76/271/DTR 76/282/RVC
Full information on the voting for the approval of this technical report can be found in the
report on voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

TR 60825-14  IEC:2004(E) – 5 –
IEC consists of the following parts, under the general title Safety of laser products:
Part 1: Equipment classification, requirements and user's guide
Part 2: Safety of optical fibre communication systems
Part 3: Guidance for laser displays and shows
Part 4: Laser guards
Part 5: Manufacturer's checklist for IEC 60825-1
Part 6: Safety of products with optical sources, exclusively used for visible information
transmission to the human eye
Part 7: Safety of products emitting infrared optical radiation, exclusively used for wireless
'free air' data transmission and surveillance
Part 8: Guidelines for the safe use of medical laser equipment
Part 9: Compilation of maximum permissible exposure to incoherent optical radiation
Part 10: Application guidelines and explanatory notes to IEC 60825-1
Part 12: Safety of free space optical communication systems used for transmission of
1)
information
1)
Part 13: Measurements for classification of laser products
Part 14: A user's guide
The committee has decided that the contents of this publication will remain unchanged until
2007. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
___________
1)
To be published
– 6 – TR 60825-14  IEC:2004(E)
INTRODUCTION
To help in the use of this technical report, an outline of the topics that are covered within it is
given below. The topics are presented in the order in which they would normally be
considered as part of a laser safety programme.
– Safety responsibilities with regard to the operation of lasers and the need for appropriate
training are covered in Clause 3.
– The meaning of the laser product classes and the assessment of laser exposure are
covered in Clause 4.
– The determination of the maximum permissible exposure (MPE), and the concept of the
hazard distance and hazard zone within which the MPE can be exceeded, are covered in
Clause 5.
– Associated laser hazards (that is, hazards other than those of eye or skin exposure to the
emitted laser beam) are covered in Clause 6.
– A three-stage process for evaluating risk (arising from both the laser radiation hazards
discussed in Clauses 4 and 5, and the associated laser hazards discussed in Clause 6) is
covered in Clause 7. These three stages are:
1) the identification of all potentially injurious situations,
2) the assessment of the risk arising from these situations and
3) the determination of the necessary protective measures.
– The use of control measures for reducing the risk to an acceptable level is covered in
Clause 8.
– The need to ensure the continuation over time of safe laser operation is covered in
Clause 9.
– The reporting of laser-related hazardous incidents and the investigation of accidents is
covered in Clause 10.
– The role of medical surveillance (eye examinations) is covered in Clause 11.
– Additional information on the use of interlock protection is given in Annex A.
– Examples of laser safety calculations are given in Annex B.
– An explanation of the biophysical effects of laser exposure to the eyes and skin is given in
Annex C.
TR 60825-14  IEC:2004(E) – 7 –
SAFETY OF LASER PRODUCTS –
Part 14: A user's guide
1 Scope and object
This technical report provides guidance on best practice in the safe use of laser products that
conform to IEC 60825-1. The terms "laser product" and "laser equipment" as used in this
document also refer to any device, assembly or system, which is capable of emitting optical
radiation produced by a process of stimulated emission. However, unlike IEC 60825-1, this
document does not cover light-emitting diodes (LEDs).
Class 1 laser products normally pose no hazard and Class 2 laser products present only a
minimal hazard. With these products, it is normally sufficient to follow the warnings on the
product labels and the manufacturer’s instructions for safe use. Further protective measures
as described in this document should not be necessary.
This document emphasizes evaluation of the risk from higher power lasers, but the users of
the lower power lasers may benefit from the information contained. See Table 1 for an
overview.
This technical report can be applied to the use of any product that incorporates a laser,
whether or not it is sold or offered for sale. Therefore, it applies to specially constructed
lasers (including experimental and prototype systems).
This technical report is intended to help laser users and their employers to understand the
general principles of safety management (Clause 3), to identify the hazards that may be
present (Clauses 4 to 6), to assess the risks of harm that may arise (Clause 7), and to set up
and maintain appropriate control measures (Clauses 8 to 11).
Laser control measures vary widely. They depend on the type of laser equipment in use, the
task or process being performed, the environment in which the equipment is used and the
personnel who may be at risk of harm. Specific requirements for certain laser applications is
given in other documents in the IEC 60825 series (see the Foreword or bibliography for the
titles of these documents).
The terms “reasonably foreseeable” and “reasonably foreseeably” are used in this document
in relation to certain specific events, situations or conditions. It is the responsibility of the
person using this document to determine what is “reasonably foreseeable” and what might
occur “reasonably foreseeably”, and to be able to defend, on the basis of risk-assessment
criteria, any such judgements that are made.
Reference is made in this document to laser “users”. This should be taken to include persons
having responsibility for safety in addition to those who actually work with or operate laser
equipment.
– 8 – TR 60825-14  IEC:2004(E)
2 Terms and definitions
For the purposes of this document, the following definitions apply.
2.1
administrative control
safety measures of a non-engineering type such as key supervision, safety training of
personnel, warning notices, countdown procedures, and range safety controls
2.2
alpha min
α min
See angular subtense (2.4)
2.3
angle of acceptance
γγγγ
plane angle within which a detector will respond to optical radiation, usually measured in
radians. This angle of acceptance may be controlled by apertures or optical elements in front
of the detector
NOTE 1 The angle of acceptance is also sometimes referred to as the field of view.
NOTE 2 For evaluation of the photochemical hazard, a limiting measurement angle of acceptance, γ , is specified.
p
The angle γ is biologically related to eye movements and is not dependent upon the angular subtense of the
p
source. If the angular subtense of the source is smaller than the limiting angle of acceptance, the actual
measurement angle of acceptance does not have to be limited. If the angular subtense of the source is larger than
the specified limiting angle of acceptance, the angle of acceptance has to be limited and the source has to be
scanned for hotspots. If the measurement angle of acceptance is not limited to the specified level, the hazard may
be over-estimated.
2.4
angular subtense
αα
αα
angle subtended by an apparent source as viewed at a point in space
NOTE 1 In this standard, for classification, the angular subtense is determined at a point not less than 100 mm
from the apparent source (or at the exit window or lens of the product if the apparent source is located at a
distance greater than 100 mm within the window or lens). For an analysis of the maximum permissible exposure
levels, the angular subtense is determined at the viewing distance from the apparent source but not less than
100 mm.
NOTE 2 The angular subtense of an apparent source is applicable in this part of IEC 60825 only in the
wavelength range from 400 nm to 1 400 nm, the retinal hazard region.
NOTE 3 The angular subtense of the source should not be confused with the divergence of the beam.
2.5
aperture
any opening in the protective housing or other enclosure of a laser product through which
laser radiation is emitted, thereby allowing human access to such radiation
2.5.1
aperture stop
opening serving to define the area over which radiation is measured
2.6
apparent source
real or virtual object that forms the smallest possible retinal image
NOTE This definition is used to determine the location of the apparent origin of laser radiation in the wavelength
range of 400 nm to 1 400 nm, with the assumption of the apparent source being located in the eye's range of
accommodation (≥100 mm). In the limit of vanishing divergence, i.e. in the case of an ideally collimated beam, the
location of the apparent source goes to infinity.

TR 60825-14  IEC:2004(E) – 9 –
The concept of an apparent source is used in the extended wavelength region 302,5 nm to 4 000 nm since focusing
by conventional lenses might be possible in that region.
2.7
beam
laser radiation that may be characterized by direction, divergence, diameter or scan
specifications
NOTE Scattered radiation from a non-specular reflection is not considered to be a beam.
2.8
beam attenuator
device which reduces the laser radiation to or below a specified level
2.9
beam diameter
d
u
beam width
diameter of the smallest circle which contains u % of the total laser power (or energy). For the
purpose of this standard d is used
NOTE In the case of a Gaussian beam, d corresponds to the point where the irradiance (radiant exposure) falls
to 1/e of its central peak value.
2.10
beam divergence
far field plane angle of the cone defined by the beam diameter
NOTE 1 If the beam diameters at two points separated by a distance r are d and d ′ , the divergence is given
63 63
by:
'
 
d − d
63 63
 
ϕ =
2 arctan
 
2 r
 
NOTE 2 SI unit: radian.
2.11
beam stop
device which terminates a laser beam path
2.12
Class 1 laser product
any laser product which does not permit human access to laser radiation in excess of the
accessible emission limits of Class 1 for applicable wavelengths and emission durations
2.13
Class 1M laser product
any laser product in the wavelength range from 302,5 nm to 4 000 nm which does not permit
human access to laser radiation in excess of the accessible emission limits of Class 1 for
applicable wavelengths and emission durations, where the level of radiation is measured but
is evaluated with smaller measurement apertures or at a greater distance from the apparent
source than those used for Class 1 laser products
NOTE The output of a Class 1M product is therefore potentially hazardous when viewed using an optical
instrument.
2.14
Class 2 laser product
any laser product, which does not permit human access to laser radiation in excess of the
accessible emission limits of Class 2 for applicable wavelengths and emission durations

– 10 – TR 60825-14  IEC:2004(E)
2.15
Class 2M laser product
any laser product in the wavelength range from 400 nm to 700 nm which does not permit
human access to laser radiation in excess of the accessible emission limits of Class 2 for
applicable wavelengths and emission durations, where the level of radiation is measured but
is evaluated with smaller measurement apertures or at a greater distance from the apparent
source than those used for Class 2 laser products
NOTE The output of a Class 2M product is therefore potentially hazardous when viewed using an optical
instrument.
2.16
Class 3R and Class 3B laser products
any laser product which permits human access to laser radiation in excess of the accessible
emission limits of Class 1 and Class 2 as applicable, but which does not permit human access
to laser radiation in excess of the accessible emission limits of Classes 3R and 3B
(respectively) for any emission duration and wavelength
2.17
Class 4 laser product
any laser product which permits human access to laser radiation in excess of the accessible
emission limits of Class 3B
2.18
collateral radiation
any electromagnetic radiation, within the wavelength range between 180 nm and 1 mm,
except laser radiation, emitted by a laser product as a result of, or physically necessary for,
the operation of a laser
2.19
collimated beam
"parallel" beam of radiation with very small angular divergence or convergence
2.20
continuous wave
CW
output of a laser which is operated in a continuous rather than pulsed mode. In this part of
IEC 60825, a laser operating with a continuous output for a period equal to or greater than
0,25 s is regarded as a CW laser
2.21
defined beam path
an intended path of a laser beam within the laser product
2.22
diffuse reflection
change of the spatial distribution of a beam of radiation by scattering in many directions by a
surface or medium.
NOTE 1 A perfect diffuser destroys all correlation between the directions of the incident and emergent radiation.
NOTE 2 This definition is different from IEV 845-04-47.
2.23
embedded laser product
laser product which, because of engineering features limiting the accessible emissions, has
been assigned a class number lower than the inherent capability of the laser incorporated
NOTE The laser which is incorporated in the embedded laser product is called the embedded laser.

TR 60825-14  IEC:2004(E) – 11 –
2.24
emission duration
temporal duration of a pulse, of a train or series of pulses, or of continuous operation, during
which human access to laser radiation could occur as a result of operation, maintenance or
servicing of a laser product. For a train of pulses, this is the duration between the first half-
peak power point of the leading pulse and the last half-peak power point of the trailing pulse
2.25
exposure duration
see exposure time (2.26).
2.26
exposure time
duration of a pulse, or series, or train of pulses or of continuous emission of laser radiation
incident upon the human body. For a train of pulses, this is the duration between the first half-
peak power point of the leading pulse and the last half-peak power point of the trailing pulse
2.27
extended source viewing
viewing conditions whereby the apparent source at a distance of 100 mm or more subtends an
angle at the eye greater than the limiting angular subtense (α )
min
NOTE Two extended source conditions are considered in this standard when considering retinal thermal injury
hazards: intermediate source and large source, which are used to distinguish sources with angular subtenses, α,
between α and α (intermediate sources), and greater than α (large sources).
min max max
Examples are viewing of some diffuse reflections and of some laser diode arrays.
2.28
fail safe
design consideration in which failure of a component does not increase the hazard. In the
failure mode the system is rendered inoperative or non-hazardous
2.29
human access
a) capability of a part of the human body to meet hazardous laser radiation either as emitted
from an aperture, or capability of a straight 12 mm diameter probe up to 80 mm long to
intercept laser radiation of Class 2, 2M or 3R; or
b) for levels of laser radiation within a housing that exceed the limits in a), the capability for
any part of the human body to meet hazardous laser radiation that can be reflected
directly by any single introduced flat surface from the interior of the product through any
opening in its protective housing
2.30
integrated radiance
integral of the radiance over a given exposure time expressed as radiant energy per unit area
–2 –1
of a radiating surface per unit solid angle of emission (usually expressed as J⋅m ⋅sr )
2.31
intrabeam viewing
all viewing conditions whereby the eye is exposed to the direct or specularly reflected laser
beam in contrast, for example, to viewing of diffuse reflections

– 12 – TR 60825-14  IEC:2004(E)
2.32
irradiance
E
quotient of the radiant flux dΦ incident on an element of a surface by the area dA of that
element:
dΦ
E =
dA
–2
NOTE SI unit: watt per square metre (W⋅m ).
2.33
laser
any device which can be made to produce or amplify electromagnetic radiation in the
wavelength range from 180 nm to 1 mm primarily by the process of controlled stimulated
emission.
NOTE This definition is different from IEV 845-04-39.
2.34
laser controlled area
area where the occupancy and activity of those within is subject to control and supervision for
the purpose of protection from radiation hazards
2.35
laser energy source
any device intended for use in conjunction with a laser to supply energy for the excitation of
electrons, ions, or molecules.
NOTE General energy sources such as electrical supply mains or batteries are not considered to constitute laser
energy sources.
2.36
laser equipment
laser product – an assembly that is or contains a laser
2.37
laser product
any product or assembly of components which constitutes, incorporates or is intended to
incorporate a laser or laser system, and which is not sold to another manufacturer for use as
a component (or replacement for such component) of an electronic product
2.38
laser radiation
all electromagnetic radiation emitted by a laser product between 180 nm and 1 mm which is
produced as a result of controlled stimulated emission
2.39
laser safety officer
one who is knowledgeable in the evaluation and control of laser hazards and has
responsibility for oversight of the control of laser hazards
2.40
laser system
laser in combination with an appropriate laser energy source with or without additional
incorporated components
2.41
limiting aperture
circular area over which irradiance and radiant exposure are averaged

TR 60825-14  IEC:2004(E) – 13 –
2.42
maintenance
performance of those adjustments or procedures specified in user information provided by the
manufacturer with the laser product, which are to be performed by the user for the purpose of
assuring the intended performance of the product. It does not include operation or service
2.43
maximum angular subtense
α max
value of angular subtense of the apparent source above which the MPEs are independent of
the source size
2.44
maximum permissible exposure
MPE
that level of laser radiation to which, under normal circumstances, persons may be exposed
without suffering adverse effects. The MPE levels represent the maximum level to which the
eye or skin can be exposed without consequential injury immediately or after a long time and
are related to the wavelength of the radiation, the pulse duration or exposure time, the tissue
at risk and, for visible and near infra-red radiation in the range 400 nm to 1 400 nm, the size
of the retinal image
NOTE 1 The values for maximum permissible exposure used in this document are those recommended by the
International Commission on Non-Ionizing Radiation Protection, and are based on the current state of knowledge of
threshold levels for laser injury.
NOTE 2 Annex B gives examples of the calculations of MPE levels.
2.45
minimum angular subtense
α min
value of angular subtense of the apparent source above which a source is considered an
extended source
NOTE MPEs are independent of the source size for angular subtenses less than α .
min
2.46
nominal ocular hazard area
NOHA
area within which the beam irradiance or radiant exposure exceeds the appropriate corneal
maximum permissible exposure (MPE), including the possibility of accidental misdirection of
the laser beam
NOTE If the NOHA includes the possibility of viewing through optical aids, this is termed the "extended NOHA".
2.47
nominal ocular hazard distance
NOHD
distance at which the beam irradiance or radiant exposure equals the appropriate corneal
maximum permissible exposure (MPE)
NOTE If the NOHD includes the possibility of optically-aided viewing, this is termed the "extended NOHD".
2.48
operation
performance of the laser product over the full range of its intended functions. It does not
include maintenance or service
2.49
optical density
OD
logarithm to base ten of the reciprocal of the transmittance τ
Symbol: D D = –log τ
– 14 – TR 60825-14  IEC:2004(E)
2.50
photochemical hazard limit
MPE that was derived to protect persons against adverse photochemical effects
NOTE An example of such adverse effects is photoretinitis, a photochemical retinal injury from exposure to
radiation in the wavelength range from 400 nm to 600 nm.
2.51
protective enclosure
physical means for preventing human exposure to laser radiation unless such access is
necessary for the intended functions of the installation
2.52
protective housing
those portions of a laser product (including a product incorporating an embedded laser),
which are designed to prevent human access to laser radiation in excess of the level required
by the laser product’s prescribed classification (generally installed by a manufacturer)
2.53
pulse duration
time increment measured between the half peak power points at the leading and trailing
edges of a pulse
2.54
pulsed laser
laser which delivers its energy in the form of a single pulse or a train of pulses. In this part of
IEC 60825, the duration of a pulse is less than 0,25 s
2.55
radiance
L
quantity defined by the formula
dΦ
L =
dA ⋅ cosθ ⋅ dΩ
where
dΦ is the radiant flux transmitted by an elementary beam passing through the given point and
propagating in the solid angle dΩ containing the given direction;
dA is the area of a section of that beam containing the given point;
θ is the angle between the normal to that section and the direction of the beam
–2 –1
NOTE 1 Unit: W⋅m ⋅sr .
NOTE 2 This definition is a simplified version of IEV 845-01-34, sufficient for the purpose of this part. In cases of
doubt, the IEV definition should be followed.
2.56
radiant energy
Q
time integral of the radiant flux over a given duration Δt
Qt= Φd
∫
Δt
NOTE SI unit: joule (J).
(IEV 845-01-27)
TR 60825-14  IEC:2004(E) – 15 –
2.57
radiant exposure
H
at a point on a surface, the radiant energy incident on an element of a surface divided by the
area of that element
dQ
H== Etd
∫
dA
–2
NOTE SI unit: joule per square metre (J⋅m ).
2.58
radiant power
radiant flux
ΦΦΦΦ, P
power emitted, transferred, or received in the form of radiation
dQ
Φ =
dt
NOTE SI unit: watt (W).
2.59
reflectance
ρ ρρρ
ratio of the reflected radiant power to the incident radiant power in the given conditions
NOTE SI unit: 1.
2.60
remote interlock connector
connector which permits the connection of external controls placed apart from other
components of the laser product
2.61
safety interlock
automatic device associated with the protective housing of a laser product to prevent human
access to Class 3 or Class 4 laser radiation when that portion of the housing is removed
2.62
service
performance of those procedures or adjustments described in the manufacturer's service
instructions which may affect any aspect of the product's performance. It does not include
maintenance or operation
2.63
single fault condition
any single fault that might occur in a product and the direct consequences of that fault
2.64
small source
source with an angular subtense α less than, or equal to, the minimum angular subtense α
min
2.65
specular reflection
reflection from a surface which maintains angular correlation between incident and reflected
beams of radiation, as with reflections from a mirror
2.66
thermal hazard limit
MPE that was derived to protect persons against adverse thermal effects, as opposed to
photochemical injury
– 16 – TR 60825-14  IEC:2004(E)
2.67
time base
emission duration to be considered for classification
2.68
tool
denotes a screwdriver, a coin, or other object which may be used to operate a screw or
similar fixing means
2.69
transmittance
ττττ
ratio of the transmitted radiant flux to the incident flux in the given conditions
NOTE SI unit: 1.
2.70
visible radiation (light)
any optical radiation capable of causing a visual sensation directly
NOTE In this part of IEC 60825, this is taken to mean electromagnetic radiation for which the wavelength of the
monochromatic components lies between 400 nm and 700 nm.
3 Administrative policies
3.1 Safety responsibilities
Safety responsibilities may be specified by national or local regulations. These specific
responsibilities should be followed. However, in the absence of any specific legislation or
regulations, the following are some general guides on responsibilities for the safe use of
lasers.
Employers and employees, and all users of lasers (including students) and those supervising
or overseeing them, have a role to play in maintaining a safe place of work and in ensuring
that their activities do not present unacceptable levels of risk to themselves or to others.
In any place of work in which lasers are in use, it is the employer's responsibility to ensure
that the risks to health arising from the use and reasonably foreseeable misuse of laser
equipment are properly assessed. The employer must take all necessary steps to ensure that
these risks are either eliminated or, where this is not reasonably practicable, reduced to an
acceptably low level.
Wherever potentially hazardous lasers are in use, the employer (or any other person having
overall responsibility) should establish a general policy for the safe management of these
hazards, although specific safety tasks may be delegated to others. This policy, which should
be an integral part of the organisation's overall safety policy, should require that all
reasonably foreseeable hazards arising from laser use are identified and that steps are taken
to control them so far as is reasonably practicable. Significant findings of this assessment
should be documented and appropriate protective measures implemented wherever
necessary to reduce the identified health and safety risks. The effectiveness of such
protective measures should be reviewed regularly. These requirements for establishing a
specific safety policy for lasers are not normally necessary where only laser products in
Class 1 or Class 2 are in use, and may not always be necessary for laser products in
Class 1M or Class 2M, but see Table 1 concerning protective control measures, 4.1.3
concerning embedded lasers and 4.2.2 concerning temporary visual effects.

TR 60825-14  IEC:2004(E) – 17 –
3.2 Competent persons
Where the employer or laser user is not able, without assistance, to properly determine the
necessary safety arrangements and protective measures for eliminating or minimising the
risks to health arising from the use of laser equipment, then the advice of a Competent
Person should be sought. The Competent Person should have sufficient skill in, and
knowledge and experience of, matters relevant to laser safety, and should provide appropriate
assistance to the employer (or to the employer's delegated representative, or laser user) in
hazard determination, risk assessment, and protective control and procedure provision.
The Competent Person need not be an employee of the organisation concerned, but may
instead be an external adviser. The advice and assistance of a Competent Person is often
only necessary temporarily, for example when first establishing appropriate protective control
measures or when evaluating the risk prior to significant changes to procedures or equipment.
3.3 Laser Safety Officer
A Laser Safety Officer should be appointed in organisations in which Class 3B or Class 4
laser products are in use. The appointment of a Laser Safety Officer is also recommended
where Class 1M and Class 2M laser products generating well-collimated beams are in use,
and which could present a hazard if viewed through binoculars or telescopes at a
considerable distance from the laser. (This can include the installation and servicing of
embedded lasers where access may be gained to higher levels of laser radiation than is
implied by the laser product’s class (see 4.1.3), or where the use of lasers of a lower
class than 3B or 4 may nevertheless still introduce a significant risk, perhaps through the
involvement of untrained people or because of the existence of associated laser hazards –
see Clause 6.)
The Laser Safety Officer should take responsibility, on behalf of the employer, for the
administration of day-to-day matters of laser safety. It is the employer's responsibility to
ensure that the person appointed as Laser Safety Officer has sufficient competence and
capability to perform this role satisfactorily. Suitable training should be provided if necessary.
The duties of the Laser Safety Officer should be agreed with the employer (or with the
employer's delegated representative) and documented. These duties should be thos
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