IEC 60335-2-104:2021 is available as IEC 60335-2-104:2021 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.

IEC 60335-2-104:2021 deals with the safety of electrical recovery and/or recycle equipment to recover and/or recycle refrigerant from air conditioning and refrigeration equipment. This applies to air-conditioning, heat-pumps and refrigeration equipment incorporating open drive or motor-compressors, their maximum rated voltages being not more than 300 V for single phase appliances and 600 V for all other equipment.
Appliances not intended for normal household use but which nevertheless may be a source of danger to the public, such as appliances intended to be used by service personnel in shops, in light industry and on farms, are within the scope of this standard.
The appliances referenced above may consist of one or more factory made assemblies. If provided in more than one assembly, the separate assemblies are to be used together, and the requirements are based on the use of matched assemblies.
This second edition cancels and replaces the first edition published in 2003. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) Clause 1 - The scope has been edited to reflect that "appliance" in this document means recovery and/or recycle equipment to recover and/or recycle refrigerant from air-conditioning and refrigeration equipment.
b) Clause 2 - Normative references were added.
c) Clause 3 - Some definitions were deleted, some were added.
d) Subclause 7.1 - Some markings were deleted, some were added.
e) Subclause 7.6 - Symbols were added for “read operator’s manual”, “operator’s manual; operating instructions” including coloring are placed in visible location; maximum allowable pressure markings following X MPa.
f) Subclause 19.11.4 was modified.
g) Subclause 21.1 was modified.
h) Subclause 21.2 was modified.
i) Subclause 22.102 was modified.
j) Subclause 22.104.1.1 was modified.
k) Subclause 22.104.5 was modified.
l) Subclause 22.104.10 was modified.
m) Subclause 22.104.11 was modified.
n) Subclause 22.105.1 was modified.
o) Subclause 22.107 was modified.
p) Subclause 30.2 was moved to Clause 29.
q) Annex AA was deleted and replaced with Annex AA.
r) Annex BB was deleted and replaced with former IEC 60335-2-104 Annex CC (normative) Compatibility requirements following addition to Annex BB.
s) Annex DD was deleted and replaced with Annex CC.
t) New Annex DD was added.
u) New Annex EE was added.
This part 2 is to be used in conjunction with the fifth edition of IEC 60335-1:2010 and its amendments.