IEC 62471-7:2023/ISH1:2025

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
IEC 62471-7
Edition 1.0  2023-02
Photobiological safety of lamps and lamp systems -
Part 7: Light sources and luminaires primarily emitting visible radiation

INTERPRETATION SHEET 1
This interpretation sheet has been prepared by IEC technical committee 34: Lighting.
The text of this interpretation sheet is based on the following documents:
DISH Report on voting
34/1322/DISH 34/1329/RVDISH
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.

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Introduction
When applying IEC 62471-7:2023, it has been found that in relation to the retinal thermal hazard
assessment of high brightness luminaires, an ambiguous interpretation could possibly occur.
This interpretation sheet provides information to facilitate correct interpretation. The publication
of this interpretation sheet has been chosen in order to quickly inform interested parties before
Amendment 1 of IEC 62471-7:2023 is developed and published.
IEC 62471-7:2023-02/ISH1:2025-07(en-fr)

1 Subclause 7.3, Table 2
For BLH-D, the column “luminaire groups of application” states that the application group BLH-D
is “not acceptable”. This wording is clarified as follows.
Interpretation
The wording “not acceptable for any luminaire” does not mean that the luminaire using a BLH-D
light source cannot be in compliance with IEC 62471-7 without further investigation. For a fixed
luminaire it is required to provide the appropriate information for the safe use and installation,
including the hazard distance according to the relevant product standard.
The requirement for the determination of the “thermal limit assessment distance” is clarified as
the hazard distance associated with the retinal thermal limit. This hazard distance is always
larger than the hazard distance based on the BLH-C limit.
2 Subclause 8.3
a) In 8.3, second paragraph, it is unclear what the relevant emission limits are.
Interpretation
For the assessment of the luminaire at 1 000 mm distance (see also Table 2, footnote d),
−2 −1
the retinal thermal limit of 28 000/α W∙m ∙sr of IEC 62471-5:2015, Table 3 is used, as
given in NOTE 1 of 8.2 of IEC 62471-7:2023. The parameter α is given in units of radian.
The retinal thermal hazard weighting function R(λ) of IEC 62471-5:2015 applies (see
IEC 62471-7:2023, Table 1, footnote a, and 8.1). An averaging FOV of 11 mrad applies for
the determination of L as is stated in the last paragraph of 8.3. The minimum value of α to
R
determine the limit equals 0,011 rad.
b) Subclause 8.3 requires consulting the relevant product standard to determine requirements
on user and installer information. At the time of writing, IEC 60598-1:2024 does not have
this requirement, leading to ambiguity on how to fulfil this requirement.
Interpretation
When the retinal thermal limit is exceeded at a distance of 1 000 mm, Subclause 8.3
requires compliance with the requirements of the relevant product safety standard. This
pertains particularly to warning labels on the product, and requirements for user information
and installer information to avoid intra-beam viewing at distances shorter than the hazard
distance. Although the scope of IEC 62471-5 is image projectors, due to the similarity of the
products, pending an update of IEC 60598-1:2024 (the luminaire standard), IEC 62471-5
can be considered as an applicable product standard for luminaires for stage lighting and
searchlights that exceed the retinal thermal limit at 1 000 mm distance.

COMMISSION ÉLECTROTECHNIQUE INTERNATIONALE
____________
IEC 62471-7
Édition 1.0  2023-02
Sécurité photobiologique des lampes
et des appareils utilisant des lampes -
Partie 7: Sources de lumière et luminaires
qui émettent pri
...