IEC TR 60479-4:2020

IEC TR 60479-4 ®
Edition 3.0 2020-02
TECHNICAL
REPORT
colour
inside
Effects of current on human beings and livestock –
Part 4: Effects of lightning strokes
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IEC TR 60479-4 ®
Edition 3.0 2020-02
TECHNICAL
REPORT
colour
inside
Effects of current on human beings and livestock –

Part 4: Effects of lightning strokes

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 13.200; 29.020 ISBN 978-2-8322-7888-8

– 2 – IEC TR 60479-4:2020 © IEC 2020
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
3.1 Definitions of technical terms . 7
3.2 Definitions of interactions . 9
4 Basic physics of lightning . 9
4.1 General . 9
4.2 Lightning occurrence . 11
4.3 Lightning flash characteristics . 12
4.4 Primary and secondary injuries . 12
4.5 Summary . 13
5 Interaction of strokes with human beings and livestock . 13
5.1 General . 13
5.2 Strike mechanisms . 14
5.2.1 Description of direct strike . 14
5.2.2 Description of contact voltage . 15
5.2.3 Description of side flash . 16
5.2.4 Description of step voltage . 16
5.2.4 Description of streamer current . 17
5.3 Specific matters regarding body response . 19
6 Effects of lightning strokes on the body of living beings . 20
6.1 General comments on effects on the body . 20
6.2 Comments on specific syndromes . 23
6.2.1 Keraunoparalysis . 23
6.2.2 Burns . 23
6.2.3 Comparison between effects of electric shock derived from electrical
systems and lightning . 24
7 Present considerations of causation . 26
7.1 Under investigation . 26
7.2 Electrical effects . 26
7.3 Thermal, field and radiation effects . 26
7.4 Traumatic injury . 26
7.5 Barotrauma . 27
7.6 Release of hormones . 27
8 Individual and crowd safety procedures . 27
8.1 General – "No place outdoors is safe" . 27
8.2 Individual actions . 27
8.3 Basic principles . 27
8.3.1 General . 27
8.3.2 Individual lightning safety in the outdoors (NOAA recommendations) . 28
8.3.3 Safe practice indoors . 28
8.4 Safety procedures for crowds . 29
Bibliography . 30

Figure 1 – Categorization of lightning types [4] . 10
Figure 2 – High resolution full climatology (HRFC) . 12
Figure 3 – Direct strike. 14
Figure 4 – Direct strike with no flashover and then with flashover . 15
Figure 5 – Contact potential . 15
Figure 6 – Side flash . 16
Figure 7 – Earth potential versus distance from the stroke base – 10 kA stroke, with
earth resistivity 100 Ωm . 17
Figure 8 – Examples of step voltages, assuming a uniform earth of constant resistivity,

and no surface flashover . 18
Figure 9 – Upward streamer . 19
Figure 10 – Current in establishment and in collapse of upward streamer . 19

Table 1 – Lightning injury and physical symptoms [8], [9], [10], [11], [12], [13], [17] . 22
Table 2 – Comparison of electrical and lightning injury [30], [34], [35], [40] . 25

– 4 – IEC TR 60479-4:2020 © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EFFECTS OF CURRENT ON HUMAN BEINGS AND LIVESTOCK –

Part 4: Effects of lightning strokes

FOREWORD
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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 TR 60479-4, which is a Technical Report, has been prepared by IEC technical committee
64: Electrical installations and protection against electric shock.
This third edition cancels and replaces the second edition published in 2011. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) lightning occurence and climatory effects around the world are depicted;
b) direct strike description is extended;
c) step voltage effects are expanded;
d) upward streamer explanation is enhanced;
...