This part of IEC 60794-1 defines test procedures to be used in establishing uniform
requirements for the environmental performance of
• optical fibre cables for use with telecommunication equipment and devices employing similar
techniques, and
• cables having a combination of both optical fibres and electrical conductors. 
Throughout this document, the wording "optical cable" can also include optical fibre units,
microduct fibre units, etc.
This document defines a test standard to determine the ability of a cable to withstand the effects
of freezing water that can immediately surround the optical fibre cable sheath by observing any
changes in the physical appearance of the sheath, or in the measured cable optical attenuation.
Method F15A is a test standard to simulate freezing of the medium surrounding a buried cable,
as in wet earth or water. Method F15A is moved from method F15 in IEC 60794-1-22:2017
without any technical changes.
Method F15B is a test standard to simulate freezing of the medium surrounding an outside cable
in a rigid conduit (duct) which is made of rigid material, for example steel. Method F15B includes
the solution to prevent the cable from being crushed when experiencing freezing conditions in
a rigid conduit (duct) which are pressure absorber pads and any other suggested means of
cable protection.
A reference guide to test methods of all types as well as general requirements can be found in
IEC 60794-1-2.