This document addresses various methods for controlling workplace hazards, emphasizing the importance of eliminating hazards at the source and using a combination of control measures like engineering controls, isolation, and ventilation. It outlines specific strategies for machine safeguarding and identifying health and safety concerns, highlighting roles for health and safety representatives in ensuring proactive hazard management. Effective control techniques include enclosure, isolation, ventilation, and the use of personal protective equipment, with the goal of preventing occupational exposure to hazards.

1. Safety, Health & Environment Management
Engineering controls

2. Index
• Controlling hazards
• Control measure
• Engineering controls
• Enclosure
• Isolation
• Ventilation
• Points to remember

3. Controlling hazards…!!!
• All workplace hazards (chemical, physical, etc.)
can be controlled by a variety of methods.
• The most effective method of controlling hazards
is to control at the source by eliminating the
hazard or by substituting a hazardous agent or
work process with a less dangerous one.
• Some methods of hazard control are more
efficient than others, but a combination of
methods usually provides a safer workplace than
relying on only one method.

4. Goal …!!!
• The goal of controlling hazards is to prevent
workers from being exposed to occupational
hazards.

5. How can you identify health and
safety problems ?
• observe your workplace;
• investigate complaints from workers;
• examine accident and near-miss records;
• examine sickness figures;
• use simple surveys to ask your co-workers about
their health and safety concerns;
• use check-lists to help you inspect your workplace;
• learn the results of inspections that are done by the
employer, the union or anyone else;
• read reports or other information about your
workplace.

6. Major categories of control measures
• Elimination
• Substitution
• Engineering
controls
• Administrative
controls
• Personal
protective
equipment.

7. Engineering controls…!!!
• An engineering control may mean changing a piece
of machinery (for example, using proper machine
guards) or a work process to reduce exposure to a
hazard.
• There are a number of common control measures
which are called “engineering controls”. These
include
1. Enclosure
2. Isolation
3. Ventilation.

8. is Enclosure…?
• If a hazardous substance or work process cannot
be eliminated or substituted, then enclosing it so
workers are not exposed to the hazard is the next
best method of control.
• Enclosing hazards can minimize possible
exposures, but does not eliminate them.
• Machine guarding is another form of enclosure
that prevents workers from coming into contact
with dangerous parts of machines.

9. Machine Guarding…!!!

10. • Crushed hands and arms, severed fingers,
blindness - the list of possible machinery-related
injuries is as long as it is horrifying.
Safeguards are essential for protecting workers
from needless and preventable injuries.
• A good rule to remember is: Any machine part,
function, or process which may cause injury
must be safeguarded.
• Goals :
• Describe the basic hazards involving machinery
including point of operation and power
transmission devices.
• Introduce control measures through effective
machine guarding principles and methods.

11. Where Mechanical Hazards Occur..?
• Point of Operation

12. Rotating parts

13. In-Running Nip Points
Rotating cylinders
Chain and
sprocket
Belt and
pulley
Rack and
pinion

14. Methods of Machine Safeguarding
• Guards
▫ fixed
▫ interlocked
▫ adjustable
▫ self-adjusting
• Devices
▫ presence sensing
▫ pullback
▫ restraint
▫ safety controls (tripwire
cable, two-hand control,
etc.)
▫ gates
 Location/distance
 Feeding and ejection methods
 automatic and/or semi-automatic
feed and ejection
 robots
 Miscellaneous aids
 awareness barriers
 protective shields
 hand-feeding tools

15. Some examples of guards
Some examples of guards
• Fixed Guard Interlocked Guard
Interlocked guard on
revolving drum

16. Examples of devices • Pullback Device Restraint Device Two-Hand
Control
Examples of devices

17. Designing machine guards
• Complete enclosure is preferable to a partial
enclosure. A partial guard should be avoided.
• Guards should fit the danger areas as closely
as possible. Caution: a moving belt rubbing
against a fixed guard can not only damage the
belt but may also be a potential source of fire.
• Guards should be combined with feeding and
ejection where possible.
• Guards should leave the operation easy to
see.

18. Unguarded machines are hazardous

19. Coming to isolation..!!!
• Isolation can be an effective method of control if a
hazardous job can be moved to a part of the
workplace where fewer people will be exposed, or if a
job can be changed to a shift when fewer people are
exposed (such as a weekend or midnight shift).
• The worker can also be isolated from a hazardous
job, for example by working in an air-conditioned
control booth.
• For example, dust-producing work should be isolated
from other work areas to prevent other workers from
being exposed. At the same time, workers in the dusty
areas must be protected and restricted to only a short
time working in those areas.

20. Safety devices on machinery
No single isolation method is effective on its
own. Isolation methods should be used in
combination to minimize the chance of
exposure.

21. Next is Ventilation…!!!
• Ventilation in the workplace can be used for two
reasons:
(1) to prevent the work environment from
being too hot, cold, dry or humid.
(2) to prevent contaminants in the air from
getting into the area where workers breathe.
• Generally there are two categories of ventilation:
local exhaust ventilation and general
ventilation.
• Whatever the type, ventilation should be
used together with other methods of
control.

22. Local exhaust ventilation
• The control of potentially hazardous airborne contaminants
such as dusts, gases, vapours and fumes, etc. can be
accomplished by capturing and removing the contaminant at
or near its source or point of generation, thus preventing the
release of the contaminant into the workroom.
• There are two common types of local exhaust ventilation used
in industry today:
(1) fumes are sucked into an open tank with side slots
and into a closed system, through which they are then
transferred to a disposal point away from the workers (a
degreasing tank is an example of this).
(2) fumes are sucked into a canopy hood which hangs
over a contaminant and forced out through a ventilation duct.

23. Components of a LEV
1.Hoods or enclosures to capture the air contaminant.
2.Ductwork leading to an exhaust fan to transport the contaminant.
3.A collection unit for particulate contaminants, or an air cleaning device for gases
before discharge to the outside air.

24. LEV in a work station
• Exhaust ventilation can also include the use of flexible piping. The end of
the pipe that draws in the contaminants (the inlet) must be placed as close
as possible to the source of the hazard in order to be effective. Flexible
piping is often used to draw welding fumes away from the worker and to
draw away contaminants in work areas that are hard to reach.

25. General ventilation :
• It is generally used for keeping the workplace
comfortable, is one of the least effective methods
of controlling hazards but one of the most
commonly .
• Air-bricks, windows and doors may be opened to
increase the general flow of air.
• The effectiveness of a general ventilation system
depends on several things, including:
1.how quickly the hazardous agent is being released
into the air.
2. how much and how quickly fresh air is coming in.
3. how the contaminated air is being removed.

26. Points to remember
about engineering controls
• Engineering controls include enclosure, isolation
and ventilation.
• If a hazardous substance or work process cannot
be eliminated or substituted, then fully enclosing
it so workers do not come into contact with it is
the next best method of control.
• Enclosing hazards can minimize possible
exposures, but does not eliminate them.
• isolating the work process or the worker does not
eliminate the hazard, which means workers can
still be exposed.
• it is always better to control the hazard as close to
the source as possible. Using personal protection
is the least acceptable and least effective of all
control measures.

27. Choosing methods of control
which control
method to use?

28. Role of the health and safety
representative
• Your role is to work proactively (to take action
before hazards become a problem) to prevent
workers from occupational exposure by making
sure hazards are controlled and kept under
control.
• It is best to enclose all toxic materials or work
processes using toxic materials. However, since
this is often not possible, try to get the employer
to enclose at least all highly toxic materials.
• Work with the union and employer to make sure
the atmosphere in the workplace is monitored
regularly for levels of hazardous materials.