What’s New in CSA Z462?
Daniel Roberts
Member, CSA, ASSE
Senior Member IEEE
Schneider Electric Canada Inc.
5985 McLaughlin Road
Mississauga, ON
L5R 1B8
Abstract – What is CSA Z462, what impact has this Standard
had on the electrical industry, and what are some of the
significant changes that will be implemented in the second
edition?
of Newfoundland and Labrador revised their electrical safety
regulations they instituted a requirement for employers to
implement an electrical safety program that is based on a
“standard acceptable to the minister.”
The “standard
acceptable to the minister” in most industrial, construction
and mining applications in Newfoundland and Labrador is
CSA Z462. WorkSafe BC recently published the following
guideline: “In meeting the requirements under section
19.10(2)(a) of the Regulation [to provide appropriate
electrical protective equipment], employers may find CSA
Standard Z462 to be valuable in assisting them in the creation
of appropriate written safe work procedures, determining the
hazards, and the necessary protection.” [1]
Index terms – electrical safety; workplace electrical safety;
CSA Z462
I. INTRODUCTION
CSA Z462 Workplace Electrical Safety provides safety
related requirements for the practical safeguarding of workers
exposed to electrical hazards in the workplace. The first
edition of CSA Z462 has now been in use in Canada since
January, 2009, and the second edition will be published in
January, 2012.
CSA Z462 is often referred to as the “Arc Flash”
Standard, or the “Live Work” Standard. While the Standard
does cover those items, it is primarily a “Don’t Work Live”
Standard that emphasizes:
• Creating an electrical safety program that is part of an
organization’s overall safety management system
• Electrical safety training
• How to create an electrically safe working condition
• The steps to go through to identify situations when
work must be performed energized
• How to plan energized work, so it is done safely.
III. CSA Z462 SECOND EDITION – WHAT’S NEW?
Hazard and risk
CSA Z462-08 and NFPA 70E-09 use the terms hazard and
risk synonymously, sometimes combining them into a single
term “hazard/risk.” They also occasionally make reference to
“greater hazards” and “hazards increasing.” [2][3]
CSA Z462-12 and NFPA 70E-12 will start to use the two
terms more in line with the usage found in Standards that
address risk, such as ISO 31000, ISO/IEC Guide 73, ISO
Guide 51, and CSA Z1002. [4][5][6][7][8][9]
As defined in these Standards, a hazard is a potential
source of harm to a worker; and risk is the combination of the
likelihood of the occurrence of harm and the severity of that
harm. Therefore, a hazard is, or is not. While the quantity of
hazards can be greater or increase in number, a specific
hazard is not greater nor does it increase. Only the risk
arising from a hazard, or combination of hazards, can be said
to increase or be greater.
In this author’s opinion, what might appear to be a subtle
change in the use of these terms is likely to be one of the
farthest reaching changes, opening up Z462 and 70E to
further alignment with internationally accepted Standards.
For example, the “hazard/risk category” method of
determining arc flash PPE requirements was left unchanged.
Both the terminology and the methodology used by the
“hazard/risk categories” are out of sync with internationally
accepted Standards that address risk.
II. IMPACT OF CSA Z462
In less than three years, CSA Z462 has achieved
remarkable uptake and acceptance by the electrical industry.
The Canadian Standards Association has sold thousands of
copies of Z462, making it one of their best selling Standards.
Many electrical contracting firms have taken electrical hazard
awareness training and have begun implementing electrical
safety programs at their workplace. Some have purchased or
are in the process of purchasing personal protective
equipment for shock and arc flash hazards.
Provincial Health and Safety regulatory authorities have
begun to encourage the use of CSA Z462. The Ministry of
Labour in Ontario has organized several contractor
information evenings to explain to employers the benefits of
adopting and implementing CSA Z462. When the Province
1
to charred remains, the orange “arc rated” raincoat selfextinguished. As shown in Figure 2, although the shell of the
arc rated garment is charred, the inside does not exhibit
evidence of any significant damage.
Worker training
CSA Z462-08 has several training requirements that relate
to worker safety, such as training in emergency procedures,
hazard recognition and avoidance, task performance and
voltage detector usage. While the 2008 edition specified that
workers should receive periodic training to maintain an
appropriate level of awareness, it was left to the employer to
determine the frequency of retraining. The 2012 edition will
specify that this retraining should occur at intervals not to
exceed 3 years; and more often if circumstances warrant.
DC safety-related work practices
CSA Z462-08 has very little information on safety-related
practices when working with DC systems. This gap has been
addressed with the addition of a Shock Protection Boundary
Table for DC and an arc flash energy calculation method for
DC. Extensive revisions have been made to deal with safetyrelated practices for batteries, battery rooms and battery
enclosures.
Arc flash boundary
The “arc flash protection boundary” has been renamed the
“arc flash boundary.” The change seems subtle, but by
deleting the word “protection” from the term it is hoped that
the function of the boundary becomes more transparent.
Most of the arc flash requirements in Z462 do not prevent
injury. Z462 Clause 4.7.3.1, Note 1 indicates that “some
situations could result in burns to the skin, even with the
protection selected, burn injury will likely be reduced and be
survivable.” CSA Z462-12 Clause 4.3.5.2 indicates that the
boundary is “the distance at which the incident energy equals
5 Joules/cm2 (1.2 calories/cm2)” which predicts the onset of
second-degree skin burns.
Such an injury would be
extremely painful, but likely survivable.
The allowance for a “provisional” 4-foot arc flash
boundary has been deleted. Experience indicated that most
people misapplied this “default” rule. The boundary must
now either be calculated or obtained from the appropriate
Hazard/Risk Category Table.
PPE tables for use with incident energy calculations
A new table has been added to assist employers to select
arc flash PPE when they perform an arc flash hazard analysis
and post the arc flash energy levels on their equipment.
Most employers currently attempt to use the Hazard/risk
category PPE Table 5 to identify arc flash PPE requirements.
However, this approach is problematic as this table was not
designed for that purpose. For example, many assume that
hazard/risk category 0 represents potential incident energy
exposures up to 1.2 calories/cm2), and this is not the case.
Hazard/risk category 0 represents a situation where the
likelihood of an arc flash event occurring is beyond
extremely low (i.e. not probable) and therefore, arc flash PPE
Arc rated vs. flame resistant
When referring to arc flash personal protective equipment
(PPE) the term “arc rated” will replace the term “flame
resistant” and the acronym “FR.” These terms have been used
interchangeably, but they do not mean the same thing. Flame
resistance is only one property of arc flash PPE that enables it
to withstand the intense energy of an arc flash event.
However, flame resistance on its own does not guarantee that
PPE will be capable of withstanding the intense energy of an
arc flash event. Some commonly available “flame resistant”
rain wear is manufactured to the flame resistant standard for
curtain fabric. However, these garments will ignite in an arc
flash event and likely cause life altering burn injuries.
Fig. 1. Charred remains of “flame resistant” raingear on left vs. intact “arc
rated” raingear on right.
Fig. 2. No significant damage inside the “arc rated” raingear.
Figure 1 illustrates the difference between the
performance of “FR” and “arc rated” raingear. Both
raincoats were simultaneously exposed to arc flash energy,
and both ignited. While the yellow “flame resistant” raincoat
continued to burn until the front of the garment was reduced
2
is not specified. The PPE specified for category 0 is general
in nature and not specific to arc flash.
The new table will also assist the electrical industry to
begin to identify arc flash PPE by its energy rating and move
away from the practice of identifying it by a category
number.
Hazard/risk category method
Employers and electrical workers that use the Table 4
Hazard/risk category method to identify their arc flash PPE
requirements will find that the table has been significantly
improved. The parameters limiting the use of the table
method will be easier to find as they have been relocated to
the table section headers. An arc flash boundary has been
added to each section of the table.
Table 5, the Hazard/risk category PPE table, has been
reformatted for ease of use. Hazard/risk category 2 was
deleted and hazard/risk category 2* was renamed hazard/risk
category 2 (i.e. the old 2* is the new 2). This reduces the
number of Hazard/Risk Categories from six to five.
As noted earlier, the terminology and the methodology
used by the “hazard/risk categories” needs to be aligned with
internationally accepted Standards that address risk. In the
author’s opinion, the most serious issue that must be
addressed is the reduction in protection in the “hazard/risk
categories” based on task, rather than based on potential
energy exposure. PPE is not task rated, it is rated according
to dose or energy-level withstand, and should be selected
accordingly.
New annex material
Two new informative Annexes have been added. The
Annex
on
High
Voltage
Substations
provides
recommendations for the safe execution of work on or around
high voltage substations. Many large industrial facilities and
non-utility generators own, maintain, and operate high
voltage substations that are the facility connection point to
the local electrical grid. The Annex on Electrostatic
Discharge describes workplace scenarios such as high speed
web operations in which the potential for shock injury from
electrostatic discharge exists. The Annex identifies methods
to prevent, control, and protect personnel from injury.
Updated annex material
Finally, there is excellent information in Annexes A and F
for organizations that consider themselves to be, or are
looking to be, safety leaders.
Annex A provides guidance to organizations that wish to
incorporate their electrical safety program into their Safety
Management System.
Annex F Hazard Identification and Risk Assessment is a
good introduction to hazard identification and risk
assessment. The language in CSA Z462 around hazard and
risk has been improved to distinguish the difference between
the two terms.
IV. CONCLUSION
In just 3 years CSA Z462 has had a significant impact on
the electrical industry. The 2012 edition incorporates
important changes that advance worker safety and begin to
align the Standard with internationally accepted Standards
that address similar subject matter. Organizations are
encouraged to use Z462 to create electrical safety program,
provide training in that program, and to imbed the program
into their safety management system.
V. VITA
Daniel Roberts is the National Safety Manager for
Schneider Electric Canada Services and Projects Division.
He has 15 years of field experience working on industrial and
commercial power distribution systems and 10 years
experience in the occupational health and safety field.
Daniel serves on various Canadian Standards Association
(CSA) technical committees and sub-committees including
Canadian Electrical Code Part 1, Z1001 OHS Training,
Z1002 OHS Hazard Identification and Elimination and Risk
Assessment and Control. He is the vice-chair of the CSA
Z462 Workplace Electrical Safety Technical Committee.
Daniel created and teaches the CSA Z462 electrical safety
workshop. Daniel is a CSA, IEEE and ASSE member.
VI. REFERENCES
Standards:
[2]
[3]
[4]
[5]
[6]
[7]
[8]
CSA Z462-08 Workplace Electrical Safety
NFPA 70E-09 Electrical Safety in the Workplace
CSA Z462-12 Workplace Electrical Safety
NFPA 70E-12 Electrical Safety in the Workplace
ISO 31000:2009(E) Risk management – Principles and guidelines
ISO/IEC Guide 73 Risk management vocabulary
ISO Guide 51 Safety aspects – Guidelines for their inclusion in
standards
[9] CSA Z1002 Occupational health and safety hazard identification and
elimination and risk assessment and control (At the time of writing this
Standard was in the final stages of development and is expected to be
published in 2012.)
Other:
[1]
3
Worksafe BC website; OHS Guidelines; accessed 2011-08-02;
http://www2.worksafebc.com/Publications/OHSRegulation/GuidelineP
art19.asp?ReportID=18763