MODULE 2 - CLASS NOTES - MCN401 - INDUSTRIAL SAFETY ENGINEERING
MODULE
2 (Personal Protection in Work Environment)
Personal protection in the work environment,
Types of PPEs, Personal protective equipment-respiratory and non-respiratory
equipment. Standards related to PPEs. Monitoring Safety Performance: Frequency
rate, severity rate, incidence rate, activity rate. Housekeeping:
Responsibility of management and employees. Advantages of good housekeeping. 5
s of housekeeping. Work permit system- objectives, hot work and cold work
permits. Typical industrial models and methodology. Entry into confined spaces.
PERSONAL
PROTECTION IN THE WORK ENVIRONMENT
Personal Protective Equipment (PPE) are attached to the human body for protection against injury or harm. PPE is used in a variety of working environments and industries, with the aim of protecting the worker from hazards while carrying out work.
TYPES
OF PPEs
Personal protection equipment’s may be
divided into following two broad groups:
·
Respiratory
Protective equipment.
·
Non-respiratory
protective equipment.
Respiratory
Protective Equipment
Atmospheric
contaminants range from relatively harmless substances to toxic dust, fumes, smoke,
vapour and gases. Processes that present hazards of exposure to harmful
substances should, if possible, be enclosed or ventilated to minimize the
hazards. If in an enclosure, ventilation or other engineering means of control
are not possible or become very costly to apply to the degree required to
ensure absolute safety, respiratory equipment should be provided to the workers.
1. Air Line Respirator.
Airline respirator essentially consists of a face piece (half or full mask) to
which air is supplied through a small diameter hose. Airline respirator
wearer's travel is restricted by the length of the air supply hose. Care should
be taken to ensure that the air supply is not contaminated and is free from
dust particles.
1. Suction Hose Mask.
It consists of a full face-piece connected to a large diameter flexible hose.
The wearer draws in air by his own breathing effort. The hose is attached to
the wearer's body by a suitable safety harness with safety line and the air
inlet of the hose is provided with a filter to arrest particulate matter.
3.
Pressure
Hose Mask. This hose mask is similar to suction
hose mask except that the air is forced through a large diameter hose by a hand
or motor operator blower. The blower is to be operated continuously while the
mask is in use.
4.
Self-Contained
Breathing Apparatus
(a) Self-contained
compressed air or oxygen breathing apparatus.
(b) Oxygen-Regenerating,
Recirculating type Self-contained Breathing Apparatus
Self-contained compressed air or oxygen breathing apparatus is a device by means of which the user obtains respirable air or oxygen from compressed air of oxygen cylinder which is an integral part of the apparatus
5.
chemical
filters
a) Canister
Gas Masks
b) Chemical
Cartridge Respirator
c) Self-rescue
type Respirators
a)
Canister Gas Masks. This consists of a canister, containing appropriate
chemical, a full face-piece. Air is drawn through the canister by the wearer
and during its passage through the chemical in the canister the contaminant
present in the incoming air is absorbed or is neutralized.
b)
Chemical Cartridge Respirator. This consists of usually, a half mask attached
to one or two cartridges). Like canisters, the cartridges are filled with
appropriate chemicals to absorb gases or vapour drawn through them.
c) Self-rescue
type Respirators. This is designed to provide the greatest possible respiratory
protection consistent with the practicability of carrying the device at all
times so that it is always available for use during escape. It consists of a
small filter element, a mouth piece, a nose clip and means of carrying it
conveniently on the body.
6.
Mechanical
filters
These remove particulate matter from the inspired air which passes through a filter The filter may be of the single use or reusable type. If these respirators are used in heavy concentrations of particulate matter, the filter will be clogged with dust particles too quickly and they may have to be replaced every time. Micro filters are special filters designed to arrest ultra-microscopic size of dust particles and these are used where extremely fine dusts are encountered.
7.
Combination filters
Combination of Chemical and Mechanical
Filter Respirators remove toxic gases and vapour and particulate matter from
inspired air. Common example of their use is in spray painting work.
Non-Respiratory
Protective Equipment
Personnel
protective devices for various parts of the body can be divided into six broad
groups:
(a)
Head Protection
(b)
Eye and Face Protection
(c)
Foot and Leg Protection
(d)
Hand and Arm Protection
(e)
Body Protection
(f)
Ear protection
Head
Protection
Head
needs protection against falling objects, flying objects, snapped ropes slings,
sparks and metal droplets from overhead welding, solar heat in outdoor
locations, and Trapping of operator's long hairs in rotating parts of machines.
Head
safe guards are designed to protect head against above mentioned hazards. The
choice of type depends upon the work situation. These safeguards may be Hard
Hats , Protective caps.
Eye and Face Protection
Numerous
eye injuries are caused by dusts, flying particles, splashes and harmful
radiation. The devices used for eye protection may be safety spectacles,
mono-goggles, impact goggles, welding goggles, foundry goggles, gas tight
goggles, welding helmets, chemical goggles etc. The devices used for face and
eye protection are face shield and the hood. The face shield provides
protection to the entire face including eyes. Hoods are used under special
circumstances for face and eye protection to deal with extremely hazardous
situation as for example, working with highly corrosive substances. The face
and eye protection devices should be heat resistant, scratch resistant, impact resistant
and lenses should have antiglare properties.
Foot and Leg Protection
Adequate
protection may have to be provided to the workers employed in certain jobs
where there may be risk of feet injury may be in handling of heavy materials,
exposure to caustic and corrosive liquid, oils and grease, molten metals, etc.
Common foot and leg protective equipment are safety shoes and boots, leggings,
foot guard and leg guards.
Hand and Arm Protection
Protection
of hands and arm becomes necessary when workers have to handle materials having
sharp ends, sharp edges or when hot and molten metals, chemicals corrosive
substances have to be handled. The protective devices used may be gloves,
mittens, hand guards and hand pads, sleeves, cuffs etc.
Gloves
are used for complete protection of hands (including fingers) and are usually
provided with wrist bands to ensure snug fit. They are made of rubber, leather,
plastic, cotton etc.
Hand
guards and hand pads are commonly used to save hands from possible injuries
while working with trucks, gritty, sharp as well as highly heated objects.
Sleeves
are meant for protection to arms (excluding hands) against injuries. Sleeves
are made of leather, asbestos, plastic etc. Cuff
guards protect the lower part of the forearm from injuries specially when
working in the proximity of heat sources, (for example, furnaces) including
sparks. The choice of material of these protective devices depends upon the
tasks or operations to be performed.
Body Protection
Sometimes
it becomes necessary to provide special protective equipment for the body in
the form of aprons, overalls, jackets and complete head to toe protective
suits. The important considerations in the selection of safety clothing will
depend upon the nature of potential hazard, degree of hazard involved and
nature of activities of the user concerned. Although complete coverage of the
body and legs is not needed in many cases and unnecessary safety clothing may
hamper the efficiency of the user, no compromise should be made with strict
safety requirements. If the user needs complete coverage, he should have it.
Ear Protection
High level of noise can also create stress that can sometimes affect one's physical and mental well being & cause accident in the work place when people cannot hear instruction and warning signals
STANDARDS RELATED TO PPES
HOUSEKEEPING:
Housekeeping
is most important aspect in ensuring safe condition at workplace in factories/plants.
Special attention needs to be paid to housekeeping by management by fixing
responsibilities and making employees answerable for any lapses. Periodic and
surprise checks should be conducted to monitor observance of housekeeping and
apply corrective measures as necessary. Housekeeping can be promoted by posters
and displays at various locations and observance of cleanliness week etc.
Advantages of good housekeeping
Good
housekeeping is essential in order to:
·
Make and maintain a
clean, neat and orderly factory work areas and its surroundings.
·
Make work area as look
pleasant, more satisfying and motivating for a worker to work.
·
Minimise fatigue and
discomfort to workers.
·
Minimise injury and
accidents.
·
Increase the life of
plant, building and the facilities it contains.
·
Avoid fire and other
hazards.
· Permit effective natural illumination and ventilation.
5 S of housekeeping
1.
Sort – go through everything; throw away rubbish, archive old stuff you may
need, decide what you need in that area on a daily and weekly basis. Everything
else must be removed. Sentiment cannot play a part here – this is a
manufacturing environment
2.
Set in Order – take the items you need in that area on a daily or weekly basis
and find the best homes for them; label, mark locations, colour code – make it
clear to anyone entering the area what should be where
3. Shine & Clean – as you are setting a
location for each item, give it a wipe and check it is is good working order.
Any broken item needs to be fixed. If your working area is particularly dirty,
more time needs to be set aside so a thorough clean can be completed.
4.
Standardisation – the new arrangement and level of cleanliness is our new
standard for each area. Take photos and display in the area; talk about the 5S
activities in your talks and daily meetings; share ideas across the factory.
This helps to create your new 5S standards and brings consistency across the
factory.
5. Sustain – if the first 4 S’s have been done well, sustaining the cleanliness and origination becomes simpler as it is clear where everything goes and each person working in an area knows where to return things at the end of the job or end of the shift. Using simple audits, we can track how we are going to maintaining our 5S baseline on a weekly basis and to also note the areas of improvement we need to make in the week ahead
RESPONSIBILITY
OF MANAGEMENT
1. Plan
and protect the housekeeping programme carefully and completely. Associate the
employees in the venture.
2. Divide
the plant and offices into cleaning zones and assign a person to each zone who
will be responsible for good housekeeping and orderliness of his zone.
3. Keep an eye on performed housekeeping schedule and conduct periodic housekeeping inspections. The following checklist may help in carrying out inspection properly.
RESPONSIBILITY OF EMPLOYEES
1. Machinery
and Equipment
·
General cleanliness
·
Containers for waste
materials
·
Machine guards on and
operating
·
Avoiding Oil, air,
water, steam leakage
·
Check - Portable
equipment. Do they hamper personnel and material movement?
2.
Materials and Storage:
·
Check - Piling and
stacking - Can material slip easily?
·
Check - Materials
protruding out of racks, bins, benches and machines etc.
3. Building
·
Windows clean and
unbroken
·
Painting and upkeep
·
Door joints clean
·
Fire extinguishers and
sprinklers clear
4.
Floors
·
Take care Slippery, wet
and oily floors
·
Take care Badly worn floor
·
Avoid Garbage, dirt or
debris from floors
·
Carefully Loose
materials
5.
Stairways and Aisles:
·
Ensure Clear and
unblocked
·
Ensure Well lighted
6.
Employee Facilities:
·
Ensure Drinking taps
clean
·
Ensure Toilets and
locker rooms clean
·
Ensure Soap and towels
available
7.
Other Aspects:
· Ensure Lamps and lamp reflector clean
·
Ensure Bulletin boards
and safety signs clean.
·
Ensure Protective
equipment and clothing clean and in good. condition
·
Ensure Electric motors
clean
·
Ensure Ventilation
unobstructed
WORK PERMIT SYSTEM
Work permit system is a formal written system used to control certain types of work that are potentially hazardous. A work permit is a document, which specifies the work to be done, and the precautions to be taken ensuring safety of workers. Work permits allows work to start only after safe procedures have been defined and considers all foreseeable hazards. Work Permit System is an important element of Safety Management which ensures a safe working environment, thereby reducing possibility of injury to personnel, protect property, avoiding fire, explosion & adverse effect on environment.
Permits
should be in printed forms, serially numbered and different colour code may be
adopted for different types of permits. Permit issuing authority should satisfy
himself that permit conditions are met before issuing permit. It is also to be
ensured that permit conditions are maintained in course of execution of the
job. After completion of the job, permits should be returned to the originating
department. Records are to be maintained for a month.
Examples
of high-risk activities are:
·
Entry into confined
spaces.
·
Work in close proximity
to overhead power lines and telecommunication cables.
·
Hot work.
·
To dig-where
underground services may be located.
·
Work with heavy moving
machinery and lifting operation closer to live power line.
·
Working on electrical
equipment.
·
Work with radioactive
isotopes.
Objectives
of the Work Permit System
1. control
over the maintenance activities by assigning responsibilities
2. ensuring
communication
3. proper
consideration to the job, its hazards and the precautions required
4. It
ensures that the work is properly defined, authorised
5. operating
personnel are aware what is going on, precautions etc.
6. persons
executing the job understand the nature and extent of hazards involved.
HOT WORK PERMIT
Any
work where temperature will be high enough to cause burning is hot work,
typically: welding, cutting, burning, heating, use of some power tools
generating heat, open flame, electric arc or continuous sparks. Hot work must
not be carried without hot work permit issued by responsible Officer.
Careless/unauthorised hot
Three types of hazardous situations need to be
considered when performing hot work:
1. The
presence of flammable materials in the equipment.
2. The
presence of combustible materials that burn or give off flammable vapors when
heated.
3. The
presence of flammable gas in the atmosphere, or gas entering from an adjacent
area, such as sewers that have not been properly protected.
COLD WORK PERMIT
Cold
work permits are green coloured permits issued for hazardous maintenance work
that does not involve “hot work”. If no flammable or explosive risks are
identified, a cold work permit is sufficient for carrying out the work. This
includes work other than hot work such as Blanking or Deblanking, Connecting
and Disconnecting pipe work, Removing and fitting of valves, work on pumps,
cleaning or mucking out oils and Semi Solid/Solid oily Residues.
ENTRY INTO CONFINED SPACES
A
confined space is one which, by design has limited openings for entry and exit
or unfavourable natural ventilation which contains or produces dangerous air
contaminants and is not intended for continuous occupancy.
Confined
spaces include storage tanks, compartments of ships. Process vessels, pits,
wells, sewers, boilers. ventilation and exhaust dusts, tunnels, pipelines etc.
The hazards associated with confined spaces can cause serious injury and death
to workers.
A
confined space has all the following characteristics:
·
The space is large
enough for an individual to bodily enter it.
·
The means for entry or
exit are limited or restricted by size or configuration, such as spaces inside
tanks, vessels, storage bins, and pits.
·
The space is not
intended for continuous human occupancy.
·
Unfavourable natural
ventilation.
Common
confined space hazards are
·
Oxygen Deficiency.
·
Flammable Atmosphere.
·
Toxic Gases.
·
Solvents.
The
employer must establish a written work procedure for confined space entry to be
followed every time a manhole, pumping station, is entered. A copy of written
work procedure must be provided to all supervisors and workers involved in
confined space entry.
The
Safe work procedure usually consists of three parts:
1. pre-entry
planning - before entry is commenced;
2. entry
procedures - for entry into working within and leaving the confined space; and
3. rescue
procedures - planning for emergency situations.
A hazard assessment must be done prior
to each entry. It must be verified when workers arrive at the work site as
actual site conditions may be different or have changed since the initial
assessment was done. The checklist can be used to assist with the hazard
assessment process.
Work
Procedures
1. Ensure
a valid entry permit is obtained.
2. Secure
the site by erecting signs, barricades and other traffic control devices
required to ensure workers are protected from traffic. Ensure that there is an
adequate warning system.
3. Ensure
that all necessary equipment is at the site and ready for use, e.g., test
equipment, fall protection equipment, communication devices, lighting and all
rescue equipment
4. Perform
a pre-entry test/assessment of the atmosphere. Appropriate respiratory
protective equipment may be needed to protect workers performing this task.
5. Ensure
that atmospheric hazards present in the confined space are identified and
controlled
Where
practical, ventilate the space to remove harmful substances and maintain an
adequate oxygen content.
6. Check
for physical hazards where the work will be carried out, e.g., cracked walls
7. If
"hot work" such as welding is to be carried out, A hot work permit
must be issued by the supervisor responsible for ensuring it is safe to carry
out the hot work involved.
8. Ensure
that all workers know what procedures to follow in case of an emergency
situation.
9. If
the atmosphere is found to contain harmful substances or is oxygen deficient,
ensure
that
workers required to enter are:
·
Protected by using
appropriate respiratory protective equipment;
·
Attended by, and in
communication with, another worker stationed at or near the entrance of the
confined space:
·
Provided with, and
understand, rescue procedures;
·
Protected by
appropriate rescue equipment available for immediate use;
·
Aware of, and familiar
with, the employer's code of practice for confined space entry;
·
Physically capable of
effecting a rescue.
Rescue
procedures
The
emergency response plan must include procedures to evacuate the workers from
the confined space when
·
An alann is activated,
·
The oxygen content
drops
·
There is a significant
change in the concentration of a hazardous substance in the space.
The
emergency response plan must include the following elements:
(a)
Identification of potential emergencies;
(b)
Procedures for dealing with identified emergencies;
(c)
Identification of the location and operational procedures for emergency
equipment;
(d)
Training requirements for emergency response;
(e)
Location and use of emergency facilities;
(j)
Fire protection requirements;
(g)
Alarm and emergency communication requirements;
(h)
First-aid services required;
(i)
Procedures for rescue and evacuation and Designated rescue and evacuation
workers.
(j)
Emergency transportation
MONITORING SAFETY PERFORMANCE
The
organisation should establish, implement and maintain procedures to measure safety
performance on a regular basis. The organisation should measure, monitor and
evaluate performance, and take preventive and corrective action. Where
appropriate, monitoring schemes for significant hazards should be in place.
Such
hazards may be classified as:
(a)
Physical hazards, such as noise, vibration. radiation, extremes of temperature,
or
(b)
Chemical hazards, e.g., toxic, flammable or explosive.
Accident
statistics and analysis are useful tools to reveal hazards. Appropriate
corrective action taken on this basis is a key-stone to accident prevention. A
systematic and thorough investigation of each accident helps build-up a pool of
information. The analysis indicates high frequency and severity locations, as
well as the identification of accident are useful pointers. Accident data, if
properly collected and analysed, indicates trends and can show where and how
problems arise. Monthly reports on safety include the total number of
man-hours, man- days worked and lost in the reported month. The report should
include all the reportable accidents, about injuries or dangerous occurrences
(fatal as well as non-fatal).
The
number of notified accidents causing injury can be compared with the number of
employees engaged in a particular activity to produce a ratio known as the
Safety Performance Index.
Computing Accident Indices
Activity rate
The
activity rate is the ratio between the number of active persons (occupied
labour force and the unemployed) and the corresponding total population
KTU
MODEL QUESTIONS
1. Which
are the different types of permit? Highlight its suitability.
2. Which
are five ‘S’ used in housekeeping?
3. Classify
the personal protective equipment. List the suitability of at least fifteen
types of PPEs. (10 Marks)
4. How
will you calculate the frequency rate? Explain with an example. (4 Marks)
5. How
will you compare the safety performance of two industries? Explain with
suitable example. (10 Marks)
Answer
key: -
safety performance can be measured in a
number of ways, usually through a combination of lag (output) and lead (input)
indicators.
Lag
indicators? measure outcomes after an incident (e.g. incident rate, lost time
work injury), and is effectively a measure of past results
Lead
indicators? measure activities to prevent or reduce the severity of an incident
in the present or future (e.g. safety training, safety audits).
6. Which
are the steps to be followed in confined space entry to protect the life a
worker.
7. Discuss
different types of personal protective equipment
8. Discuss
about how to compare the safety performance of two industries.
9. Discuss
the significance of work permit system in accident prevention.
Dear Faculty & Students ,
Corrections will be done with proper acknowledgement.
Thank you
Dr Manoj Kumar B