What is a Job Hazard
Analysis?
One way to increase the knowledge of hazards in the workplace is
to conduct a job hazard analysis on individual tasks. A job hazard
analysis (JHA) is a procedure which helps integrate accepted safety
and health principles and practices into a particular operation. In
a JHA, each basic step of the job is examined to identify potential
hazards and to determine the safest way to do the job. Other terms
used to describe this procedure are job safety analysis (JSA) and
job hazard breakdown.
Some individuals prefer to expand the analysis into all aspects
of the job, not just safety. This approach, known as total job
analysis, job analysis or task analysis, is based on the idea that
safety is an integral part of every job and not a separate entity.
In this document, only health and safety aspects will be considered.
The terms "job" and "task" are commonly used interchangeably to
mean a specific work assignment, such as "operating a grinder,"
"using a pressurized water extinguisher," or "changing a flat tire."
JHAs are not suitable for jobs defined too broadly, for example,
"overhauling an engine"; or too narrowly, for example, "positioning
car jack."
What are the
benefits of doing a Job Hazard Analysis?
The method used in this example is to observe a worker actually
perform the job. The major advantages of this method include that it
does not rely on individual memory and that the process prompts
recognition of hazards. For infrequently performed or new jobs,
observation may not be practical. With these, one approach is to
have a group of experienced workers and supervisors complete the
analysis through discussion. An advantage of this method is that
more people are involved allowing for a wider base of experience and
promoting a more ready acceptance of the resulting work procedure.
Members of the joint occupational safety and health committee should
participate in this process.
Initial benefits from developing a JHA will become clear in the
preparation stage. The analysis process may identify previously
undetected hazards and increase the job knowledge of those
participating. Safety and health awareness is raised, communication
between workers and supervisors is improved, and acceptance of safe
work procedures is promoted.
The completed JHA, or better still, a written work procedure
based on it, can form the basis for regular contact between
supervisors and workers on health and safety. It can serve as a
teaching aid for initial job training and as a briefing guide for
infrequent jobs. It may be used as a standard for health and safety
inspections or observations and it will assist in completing
comprehensive accident investigations.
What are the four
basic steps?
Four basic stages in conducting a JHA are:
- selecting the job to be analyzed
- breaking the job down into a sequence of steps
- identifying potential hazards
- determining preventive measures to overcome these hazards
What is important
to know when "selecting the job"?
Ideally, all jobs should be subjected to a JHA. In some cases
there are practical constraints posed by the amount of time and
effort required to do a JHA. Another consideration is that each JHA
will require revision whenever equipment, raw materials, processes,
or the environment change. For these reasons, it is usually
necessary to identify which jobs are to be analyzed. Even if
analysis of all jobs is planned, this step ensures that the most
critical jobs are examined first.
Factors to be considered in assigning a priority for analysis of
jobs include:
- Accident frequency and severity: jobs where accidents occur
frequently or where they occur infrequently but result in
disabling injuries.
- Potential for severe injuries or illnesses: the consequences
of an accident, hazardous condition, or exposure to harmful
substance are potentially severe.
- Newly established jobs: due to lack of experience in these
jobs, hazards may not be evident or anticipated.
- Modified jobs: new hazards may be associated with changes in
job procedures.
- Infrequently performed jobs: workers may be at greater risk
when undertaking non-routine jobs, and a JHA provides a means of
reviewing hazards.
How do I break the
job into "basic steps"?
After a job has been chosen for analysis, the next stage is to
break the job into steps. A job step is defined as a segment of the
operation necessary to advance the work. See examples below.
Care must be taken not to make the steps too general, thereby
missing specific steps and their associated hazards. On the other
hand, if they are too detailed, there will be too many steps. A rule
of thumb is that most jobs can be described in less than ten steps.
If more steps are required, you might want to divide the job into
two segments, each with its separate JHA, or combine steps where
appropriate. As an example, the job of changing a flat tire will be
used in this document.
An important point to remember is to keep the steps in their
correct sequence. Any step which is out of order may miss potential
hazards or introduce hazards which do not actually exist.
Each step is recorded in sequence. Make notes about what is done
rather than how it is done. Each item is started with an action
verb. Appendix A illustrates a format which can be used as a
worksheet in preparing a JHA. Job steps are recorded in the left
hand column, as shown below:
Sequence of Events |
Potential Accidents or
Hazards |
Preventive
Measures |
Park vehicle |
|
|
Remove spare and tool kit |
|
|
Pry off hub cap and loosen lug bolts
(nuts). |
|
|
And so on..... |
|
|
This part of the analysis is usually prepared by watching the
worker do the job. The observer is normally the immediate supervisor
but a more thorough analysis often happens by having another person,
preferably a member of the joint occupational health and safety
committee, participate in the observation. Key points are less
likely to be missed in this way.
The worker to be observed should be experienced and capable in
all parts of the job. To strengthen full co-operation and
participation, the reason for the exercise must be clearly
explained. The JHA is neither a time and motion study in disguise,
nor an attempt to uncover individual unsafe acts. The job, not the
individual, is being studied in an effort to make it safer by
identifying hazards and making modifications to eliminate or reduce
them. The worker's experience can be important in making
improvements.
The job should be observed during normal times and situations.
For example, if a job is routinely done only at night, the JHA
review should also be done at night. Similarly, only regular tools
and equipment should be used. The only difference from normal
operations is the fact that the worker is being observed.
When completed, the breakdown of steps should be discussed by all
the participants (always including the worker) to make that all
basic steps have been noted and are in the correct order.
How do I "identify
potential hazards"?
Once the basic steps have been recorded, potential hazards must
be identified at each step. Based on observations of the job,
knowledge of accident and injury causes, and personal experience,
list the things that could go wrong at each step.
A second observation of the job being performed may be needed.
Since the basic steps have already been recorded, more attention can
now be focused on potential hazards. At this stage, no attempt is
made to solve any problems which may have been detected.
To help identify potential hazards, the job analyst may use
questions such as these ( this is not a complete list):
- Can any body part get caught in or between objects?
- Do tools, machines, or equipment present any hazards?
- Can the worker make harmful contact with objects?
- Can the worker slip, trip, or fall?
- Can the worker suffer strain from lifting, pushing, or
pulling?
- Is the worker exposed to extreme heat or cold?
- Is excessive noise or vibration a problem?
- Is there a danger from falling objects?
- Is lighting a problem?
- Can weather conditions affect safety?
- Is harmful radiation a possibility?
- Can contact be made with hot, toxic, or caustic substances?
- Are there dusts, fumes, mists, or vapours in the air?
Potential hazards are listed in the middle column of the
worksheet, numbered to match the corresponding job step. For
example:
Sequence of Events |
Potential Accidents or
Hazards |
Preventive
Measures |
Park vehicle |
a)
Vehicle too close to passing traffic
b) Vehicle on uneven, soft ground
c) Vehicle may roll. |
|
Remove spare and tool kit |
a)
Strain from lifting spare. |
|
Pry off hub cap and loosen lug bolts
(nuts). |
a)
Hub cap may pop off and hit you
b) Lug wrench may slip |
|
And so on..... |
a)
... |
|
Again, all participants should jointly review this part of the
analysis.
How do I
"determine preventive measures?"
The final stage in a JHA is to determine ways to eliminate or
control the hazards identified. The generally accepted measures, in
order of preference, are:
1. Eliminate the hazard
This is the most effective measure. These techniques should be
used to eliminate the hazards:
- Choose a different process
- Modify an existing process
- Substitute with less hazardous substance
- Improve environment (ventilation)
- Modify or change equipment or tools
2. Contain the hazard
If the hazard cannot be eliminated, contact might be prevented by
using enclosures, machine guards, worker booths or similar devices.
3. Revise work procedures
Consideration might be given to modifying steps which are
hazardous, changing the sequence of steps, or adding additional
steps (such as locking out energy sources).
4. Reduce the exposure
These measures are the least effective and should only be used if
no other solutions are possible. One way of minimizing exposure is
to reduce the number of times the hazard is encountered. An example
would be modifying machinery so that less maintenance is necessary.
The use of appropriate personal protective equipment may be
required. To reduce the severity of an accident, emergency
facilities, such as eyewash stations, may need to be provided.
In listing the preventive measures, use of general statements
such as "be careful" or "use caution" should be avoided. Specific
statements which describe both what action is to be taken and how it
is to be performed are preferable. The recommended measures are
listed in the right hand column of the worksheet, numbered to match
the hazard in question. For example:
Sequence of Events |
Potential Accidents or
Hazards |
Preventive
Measures |
Park
vehicle |
a) Vehicle too
close to passing traffic
b) Vehicle on uneven, soft ground
c) Vehicle may roll. |
a) Drive to
area well clear of traffic. Turn on emergency flashers
b)Choose a firm, level area
c) Apply the parking brake; leave transmission in gear or
in PARK; place blocks in front and back of the wheel
diagonally opposite to the flat |
Remove spare
and tool kit |
a) Strain from
lifting spare. |
a) Turn spare
into upright position in the wheel well. Using your legs and
standing as close as possible, lift spare out of truck and
roll to flat tire. |
Pry off hub cap
and loosen lug bolts (nuts). |
a) Hub cap may
pop off and hit you b) Lug wrench may
slip |
a) Pry off hub
cap using steady pressure
b) Use proper lug wrench; apply steady pressure
slowly. |
And so
on..... |
a)
... |
a)
... |
How should I make
the information available to everyone else?
JHA is a useful technique for identifying hazards so that
measures can be taken to eliminate or control them. Once the
analysis is completed, the results must be communicated to all
workers who are, or will be, performing that job. The side-by-side
format used in JHA worksheets is not an ideal one for instructional
purposes. Better results can be achieved by using a narrative-style
format. For example, the work procedure based on the partial JHA
developed as an example in this document might start out like this:
1. Park vehicle.
a) Drive vehicle off the road to an area well clear of traffic,
even if it requires rolling on a flat tire. Turn on the emergency
flashers to alert passing drivers so that they will not hit you.
b) Choose a firm, level area so that you can jack up the vehicle
without it rolling.
c) Apply the parking brake, leave the transmission in gear or
PARK, place blocks in front and back of the wheel diagonally
opposite the flat. These actions will also help prevent the vehicle
from rolling.
2. Remove spare and tool kit.
a) To avoid back strain, turn the spare up into an upright
position in its well. Stand as close to the trunk as possible and
slide the spare close to your body. Lift out and roll to flat tire.
3. Pry off hub cap, loosen lug bolts (nuts).
a) Pry off hub cap slowly with steady pressure to prevent it from
popping off and striking you.
b) Using the proper lug wrench, apply steady pressure slowly to
loosen the lug bolts (nuts) so that the wrench will not slip and
hurt your knuckles.
4. And so on.
Appendix A: Sample
form for Job Hazard Analysis Worksheet
Job Hazard Analysis
Worksheet |
Job: |
Analysis By: |
Reviewed
By: |
Approved
By: |
Date: |
Date: |
Date: |
Sequence of Steps |
Potential Accidents or
Hazards |
Preventative
Measures |
|
|
|
Appendix B:
Sample forms for Tasks and Job Inventory
Tasks with Potential Exposure to
Hazardous Materials or Physical
Agents |
Analysis By: |
Reviewed
By: |
Approved
By: |
Date: |
Date: |
Date: |
Tasks |
Name of Material or Physical Agent |
Location |
|
|
|
Job Inventory of Hazardous
Chemicals |
Analysis By: |
Reviewed
By: |
Approved
By: |
Date: |
Date: |
Date: |
Name of Chemical |
Route of Entry and Physical State |
Controls |
|
|
|
Document last
updated on March 5, 1998
Copyright
©1997-2005 Canadian Centre for
Occupational Health & Safety
|