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Introduction to Safety and Signs, Signals in Construction
Yes, so, today's class we will continue with what we have discussed in the previous lecture.
So, in the previous class we have discussed about lots of terminology on safety, accidents,
injury, then ill health and so on and we also discussed is there a pattern on safety on accident.
So, that also we have reviewed and seen. So, in continuation to that, so, accident is always
considered as unexpected, unplanned and so on.
But it looks like there is a pattern on accident happening in many of the construction sites.
So, in the same way a lot of researchers have also explored. Is there any reason behind
accidents to happen? And accordingly, there are so many models and theories which has
come in and which are collectively called as theory of accident causation. And the origin and
the commonality between the 2 theories and not in any particular order.
So, the few theories are accident prone as theory wherein a person as such is responsible for
an accident. For example, a person may be doing things fast and so on so, he may be every
time getting hurt here and there. So, that is primarily reason for accident prone as theory
given the same environment, same situation, only few workers are always accident prone.
That is what is accident prone theory. Then the other one is goals, freedom, alertness theory
and adjustments stress theory. And here one theory is on positive side which is a goal
freedom alertness and the other one is on the negative side, which is called adjustment stress.
So, given complete freedom to the workers and if they know how to do their work and you
encourage them and motivate them, then obviously, they can come up with better ideas on
accident prevention and so on and safety can be really curtailed and managed.
Adjustments stress talks about the pressure you give on to the workers in terms of schedule
and the internal pressure which the worker has maybe in terms of any ill health in the family
or some medical issues or death of someone in the family. So, that can always have a mental stress which is going on into the worker. So, when that is settled, then obviously the accidents
can be controlled.
Another one is distractions, primarily the hazards prevailing in the construction site can be a
major distraction as to should I focus on the hazard or should I get my task done. So, this
dilemma can always be either you go slow on productivity or you maintain your productivity
and thereby you are getting an accident. And there are a lot of other theories like systems
model epidemiological model and Rasmac’s work behaviour model, potential accident
subject model, Bird’s domino model and so on.
Now, we are going to talk mainly about Bird’s domino model because I feel that is very close
to many of the accidents which happen in construction sites.
(Refer Slide Time: 03:36)
So, this theory is actually it is a commonality features are there between 2 theories which
exist in our accident causation. One is domino theory and the other one is chain of events
theory, to me both have a lot of similar features. For example, in dominoes theory, maybe
there are a lot of packs of cards and something triggered, something and as a result, you get a
series of events and an accident has happened.
Another one is chain of events theory where there are a lot of these oval links which we call
interlinked factors, which are all called chains and as a result, something happened and an
accident happened. Even in domino pack of card if one pack is, if one card is removed, the
accident could need have occurred. And the other cards would have been standing in position.Same way even in the chain, all links are primarily called as vital components for accident
causation and if any one link is broken, then obviously the accident can be stopped or
controlled. So, each pack of card, each card and in domino is also a vital factor same way
each link here is also a vital factor. So, both talks about the same thing, so accident number
normally what happens is people just see only on the final result.
The final result can be either a malfunction equipment or it can be a worker who has messed
up with something in the workplace or maybe he did not wear a PPE whatever it is. So, you
actually corner down on some issues which is primarily what is called as a direct cause of
accident. But if you look at the background there would have been so, many indirect causes
or basic causes, which may trigger this direct cause in a way direct cause are those which are
in a way linked to the unsafe acts.
Because some as I told in the previous class itself some worker is involved in an accident
even if it is an equipment malfunction, still some worker has gone and started operating a
faulty equipment. So, there is some human intervention in any accident if you look at and if
you do accident investigation also you may be pointing out on someone as a result of any
injury that has happened.
So, this is on unsafe acts, if you do look at indirect causes, it can be unsafe conditions or it
can be some other means of management and so on to make you understand better, I can give
a small example here. So, in one construction site, there was a worker who did not wear
proper PPE and something fell on his head when he was working in the site and there was a
Now, this, what happened is when the case was really analyzed in the peripheral level, it was
found out that the worker did not wear a proper PPE, so violation of safety norms and
practices. So, the worker was actually cornered for the accident and it was considered it was
his mistake that the accident happened, but now, if you look at the background reasons and so
So, this worker was not given a proper orientation and our training session wherein he was
aware where to collect his PPE, whom to approach for faulty PPE and if there is any issues with the PPE whom to really to report and so on. So, he was not given a proper training and
orientation. So, there were so many unknowns for him and which resulted in due course of
time, when he started working on in the construction site, he stopped wearing a proper PPE at
And if you look at the management side, there were some thefts and misuse with the PPE. So,
they made all the workers to fill a very lengthy form on collecting a PPE and far surrendering
a PPE. So, which the workers were really reluctant to do and after some time, they thought it
is like a nuisance or an unnecessary work to be done and hence, they stopped collecting a
PPE itself. So, misuse of PPE the management wanted to correct.
So, they did approach but that approach was not in favour to the workers or they did not like
that approach and as a result, many of the workers in the same side stop wearing a PPE. So, if
you see, so, these issues are all can be seen as one, one link in the chain or it can be viewed as
a pack in the domino cards. So, this is primarily the theory behind accident causation and
which I feel many of the accidents that happen in sites are not just one factor it may be so
many other linked factors as a result accident is happening in our site.
So, injuries are generally caused by actions of proceeding factors and removal of 1 or 2
factors which can be unsafe act or hazardous condition can always negate the action of
preceeding act factors and in doing so can prevent the accidents and injuries. So, even in the
chain of events theory, every link in the chain is a vital component of accident causation and
hence every link is a potential factor for accident prevention.
So, you have to think about it. Some of the examples, some of the issues can be social
environment, fault of the person, unsafe act or unsafe conditions, the actual injury and so on.
So, always during accident investigation, never look at only the final issue behind you have
to have a broad view on what really happened in the accident occurred.
(Refer Slide Time: 09:38)And just a summary of all the theories of accident causation, many of the theories and models
are not necessarily the reality because in reality you may have something very different. You
may analyze all the theories come up with them some solutions and observations and that
may not be happening in reality because reality is ultimately different and any single theory
will not suit for all the circumstances of any construction site.
And hence many of these theories have their own drawbacks. Although the theories stand
good under certain circumstances and these theory fails under many other circumstances.
Because most of the theories address only particular problems rather than a generalized set of
a construction industry and it cannot be applied to all construction scenarios also. So, in a
way you may have to have combinational approach maybe 2 or 3 theories in hand to look at a
problem and the solution.
But the better issue more than this is better to be visible with your sense organs, in the sense
see everything clearly and listen to everything properly, think what is going on in and around
you and also react to what is happening and try to understand what is happening in the site.
So, it is instead of saying I did not see, I did not think and I did not know it is a very good
poster on accident causation, it is better to listen, to see and then think before you do not even
have any time to react and it becomes too late for you to react.
(Refer Slide Time: 11:20)Now, if you look at all these accidents, every industry maintains some sort of statistics on all
the accidents. And there are so many statistics available again, these statistics are different
from each other under different perspective and they are all collected for different reasons.
And a few of them are for selecting the safe contractor, few of them are to understand for a
company's perspective, whether the safety is improved or not.
If they want to have a new safety policy in place and they wanted to know how the safety
performances in the construction site then they do all these statistics analysis. And few of the
statistics which are offered in the IS code are given here. One is frequency rate for last time
injury and reportable last time injury and the other one is severity rate for last time injuries
and reportable last name injury and the third one is incident rate for last time injuries and
same for reportable lasting injury.
Frequency rate as the name implies, it talks about number of accidents which happened,
severity rate talks about the impact of these accidents. So, primarily it is measured in terms of
mandates and the incident rate also talks about what is the total number of people to the
average number of workers employed. So, all these 3 indices are used in construction for
(Refer Slide Time: 12:53)Now, if you look at how are these mandays calculated? Now, this is where you should be
really thinking about how our life of a workers is calculated in terms of some numbers. So,
this is also given in the IS code which is primarily called scheduled charges for disabilities, if
you see here there are 2 parts, total disablement and partial disablement. So, death, loss of
limbs or severe facial disfigurement, absolute deafness.
And all these are considered as 100% loss of earning capacity which implies the worker is no
longer fit enough to earn and after the accident has happened. And the equal and mandays
lost is taken us 6000 only. So, this is how the calculations are done even today. And part B is
on partial disablement amputation at hip is taken as 90% loss, loss of 4 fingers is considered
as 50% loss.
Loss of 3 fingers in one hand is considered as 30% loss, loss of 2 fingers is considered as
20% loss and accordingly the equal and mandays is calculated as 3000, 1800 and so on. Loss
of 1 eye wherein the other is completely normal, it is considered as 40% hearing loss and
accordingly the mandays is lost is calculated. And even in the finger is it a whole finger or 2
phalanges or 1 phalanges and accordingly the rate of earning capacity is calculated and equal
on mandays lost is calculated. So, this is an IS code through which the claims, compensation
and also the severity of the rates are all calculated.
(Refer Slide Time: 14:46)Now, the real last question is whose responsibility is safety? It looks like there are so many
interlinked factors, so many people are involved. That is what we have seen. That is what the
theory also says. So, whose responsibility is safety? Primarily, it is a worker’s responsibility
because they are the one who is the victim, they are the one who gets injured or is it
Safety is everyone's responsibility that is what you have to understand here. The accidents of
primary concern are those in which the personal injuries are sustained primarily it goes on to
the workers level, but keep in mind, the workers are the one who are the ones who get injured
and the decisions of how the workers should act in the construction site and how they have to
perform the tasks are given by a decision maker who are the owners and who may not get
injured at all.
So, that is ironical statement here. So, injuries are generally sustained by persons who do not
want to get injured, that is injuries occur even though people really do not want to be
involved in accidents, but normally know they could not take many steps to avoid them, they
are not a decision maker, that is where is the real scenario in construction or other industries
Injured ones are the employees and the decision makers are the ones who are not injured are
the employers. So, many of the safety standards available, they say it is a moral and legal
obligation of employers to provide safety to their employees and it is an employer's duty to take care of their employees and to provide them a safe system or place of work to provide
them good machinery and plant which are safe to use.
And also, competent supervision and suitable training so that they can work safely in the sites
and also there should be a caring selection of fellow employees. So, the motto of any
construction project should be safety is everyone's responsibility and not only the workers
(Refer Slide Time: 16:54)
Now, if you see the history in the last class, I have also told you that there is an improvement
in the number of fatalities. So, when did safety come into practice or existence and what is
the history behind safety in construction industry and one in the late 1800s, insurance plans
became popular? And this is not on every country, this is primarily in few developed
countries only for workers in high-risk job positions.
And only in 1900, so 300 miners out of every 1 lakh people employed by killed on the job
manually and hence, the safety became a very serious concern. And in 1910, there was a
worker's compensation law, which was passed by New York and after then the OSHA act
came in the OSHA act was passed in 1970. This is primarily to safeguard the lives of
American workers, because there were so many death and fatality with a lot of workers in
And as a result, OSHA act was a first act which came into practice for safeguarding on health
and safety well being of the workers. And in after then health issues came in and today, we have lots of digital technology, which we can also foresee and what are the hazards and how
many safety programs can be implemented, what can be effective, what will go wrong. So,
we can all have so many virtual models and digital technology in place using BIM, AR or VR
and so on with which we can have a lot of improvements in safety are really possible these
days. And if the real motive is to cut down on zero accidents in the site, I think it is doable in
any construction site.
(Refer Slide Time: 19:02)
Now, how is this evolution, researchers have also talked about how this evolution of safeties
there are it is also called behaviour based safety. So, this has 3 phases. The first one is
traditional phase and then we have transitional phase and then the innovative phase.
Traditional phase is primarily the first age of safety, so which is primarily towards 1950s to
70s. And primarily, it is on technology only.
After the in the second age of safety came in lot of human factors were there. So, attention to
safe work procedures, employee training programs, engineering controls and health issues
were all addressed this happened in 1970s to 1990s and so on. Then the third age that is
primarily an organizational factor and this is primarily called innovative face and wherein
mutual trust, organizational issues and OHS integrated into decision making, emphasis on
risks and so on elimination of risks by including safety.
So, all these came into existence. Now safety is an embedded part of the whole lifecycle of a
project and not viewed as a technical factor. So, this is the trend with which the safety has
been improved and it is there right now.(Refer Slide Time: 20:17)
Now, let us talk about the different standards which are available. So, I am not going to talk
about all the standards, but only the few famous standards are OSHA, OSHA is nothing but
occupational safety and health act, which is developed by the United States of America and
then we have OSHAS. OSHAS is nothing but same occupational safety and health
assessment series that is followed by British Standard, that is primarily a British Standard.
And then we have ISO, which is primarily an international standardization for organization.
There also, we have a standard which came in recently. And we also have BoCW act, which
is primarily for Indian scenario. So, these 4 I am going to give a small idea on what are these
different acts. And most of the guidelines, which I will be covering in this particular course
will be primarily from IS codes and innovates BoCW act mixed together.
And also on OSHA act, which is the American standards and others are all very generic. So, I
will be covering a lot of parts from this OSH act and IS codes. So, until 1970, as I told you,
there were no national laws for safety and health hazards. And this occupational safety and
health act came in 1970 and it became implemented only in 1971. Prior to that, on average,
researchers have reported at least 15 workers were dying every day due to job injuries.
And this OSH act is also covering other sectors, not only construction. And it is an agency of
US department of labour, so main responsibility of OSHA is worker safety and health
protection. And the mission is to save lives, prevent injuries and protect the health of
American workers.(Refer Slide Time: 22:17)
That was a main motive behind when OSHA came in and OSHA standards are generally
applicable for 4 groups. One is general industry, other one is construction, third one is
maritime and the last one is agriculture. And here, worker rights under OSHA, so they know
about different hazardous chemicals. They inform about injuries and illnesses to the
employer. They can complain or request hazard correction from the employer.
They can also get training from the OSHA and hazard exposure and medical records, file a
complaint with OSHA and also safe and healthy workplace and a healthy workplace. So,
these are all the different rights under OSHA act. Contractors needed to realize that workers
had a reasonable right to expect a safe and healthy workplace. So, the OSHA was mandated
to develop a set of regulations specifically for the construction industry that would safeguard
those who are working in the construction industry.
And as such, these regulations were divided into sub parts from A to Z and also additional
sub parts are also there and they are found in title 29 of the code of federal regulations which
is in short form referred as a 1926 CFR. So, this is how the OSHA guidelines came in. And
these guidelines were revised in 1996 as well.
(Refer Slide Time: 23:47)So, what all it covers in construction, so it covers asbestos workers, bricklayers, carpenters,
cement masons, construction workers, electricians, elevator constructors, glaciers, iron
workers, then operating engineers, painters, pile drivers, pipe fitters, plumbers, roofers,
stonemasons, almost every side of the construction trade workers are taken into consideration
and accordingly the subparts were formulated.
(Refer Slide Time: 24:18)
If you look at the 29 CFR regulations, you will see all the subparts here. So, many of the
operations which I will be covering. So, I will be using most of the sub parts and in a way, I
would have covered almost all of the sub parts and additional IS codes in this particular
course. Subpart A general, B interpretations and C talks about general health and safety
provisions.D is on occupational health and environment controls, then subpart E is primarily on personal
protective and life saving equipment, then F is on fire protection and prevention, G is on sign,
signals and barricades. H is on material handling storage and disposal, I is on tools, hand and
power, J on welding and cutting, K electrical, L scaffolds, M fall protection, N helicopters,
hoists, elevators and conveyors.
And O is on motor vehicles and mechanized equipment, P excavation, Q concreting, R steel,
S underground construction, caissons, cofferdams and so on, T demolition, U blasting and
use of explosives, then V is on power transmission, W is on rollover protective structures and
overhead protection, X is on stairways and ladders, Y diving, Z is on toxic and hazardous
AA is on confined spaces and CC is on cranes and derricks. So, almost every part of
construction is covered in these OSHA regulations.
(Refer Slide Time: 25:48)
OSHA agencies: So, how is this occupational safety and health act operates or is functional, it
functions with the help of 3 bodies, which are called as agencies. One is an administration
arm; other one is primarily reviews arm and review place and the third one is primarily a
research arm. So, the administration arm is primarily called OSHA and colloquially we start
calling the OSH act as if it is OSHA only. So, OSHA is primarily occupational safety and
health administration.So, there are many duties or jobs which the OSHA does, it promulgates new regulations,
enforces compliance with the regulations, gather statistics on injuries and job-related
illnesses. And the second arm is nothing but occupational safety and health review
commission. That is primarily to hear cases, to conduct hearings on OSHA citations and
finalities were contested.
It also reviews appeals on files and also on abatement or the correction periods. And the other
one is a research arm and the research arm is not part of OSHA, but it also supports the
OSHA act. Although the national NIOSH was a requirement of OSHA, but it is not part of
the OSHA it is a research for OSHA. As a result, it helps for recommending new safety and
health standards to OSHA.
Conducts various research works on safety and health problems, conduct hazard analysis of
the workplace when called upon and also published a sandbar listing of all known toxic
substances and recommends exposure limits, conduct training for the qualified personnel.
(Refer Slide Time: 27:47)
So, these are the different ways with which the OSHA act works. Then also there is
something which you should understand about violations and penalties. And as a result, the
OSHA act was very popular and it could, the accidents were really controlled and minimized
as a result of the heavy penalty imposed on all the violations. So, leads to serious no penalty
other than serious up to 7,000 dollars per violation.Then serious 1500 to 7,000 dollars per violation, wilful, no death or repeat violations up to
70,000 dollars per violation and wilful death results. So, up to 2 lakhs 50,000 dollars or even
5 lakh dollars for a corporation and 6 months in jail. Wilful death results second violation, so
same fine amount, but 1 year in jail. So, if you see here, the penalties or the fines imposed on
any citation of OSHA was really high and the number of accidents were managed and it was
controlled. Falsification of documents 10,000 dollars 6 months in jail, a failure to post official
documents 7,000 dollars per poster, failure to correct cited (29:05) violations 7000 dollars per
day till abated.
(Refer Slide Time: 29:09)
Now, we will move on to OHSAS 18001 and this is 2007 is a latest series. So, as I told
OHSAS is nothing but occupational health and safety assessment series. And it is also in
short form referred as BSOHSAS 18001. So, BSI which is nothing but the British Standards
Institution group decided to adopt OHSAS which is 18001 and the OHSAS 18002 as one of
the British standards in implementing occupational safety and health in the construction
And this can be really aligned with ISO 9001 which is on quality management systems. And
ISO 14001, which is primarily on environmental system. So, compliance with OHSAS 18001
enabled organizations to demonstrate that they had a system in place for occupational safety
(Refer Slide Time: 30:07)Our next is ISO 45001. So, since many countries had their own national policies for
implementing occupational safety and health, ISO came forward in having a global policy or
international standard for occupational safety and health. So, this was launched in March
And till March 2021 many of the organizations including OHSAS 18001 can all easily
get migrated to ISOs, you can easily migrate and then get a certification on ISO.
And it is easily doable they also have a very broad framework on how to migrate from any
national scheme to ISO scheme. So, ISO 45001 is a new ISO standard for occupational safety
and health. It has become one of the most eagerly awaited global standards in the world
towards occupational safety and health in the site. So, every day 1000s of lives were lost and
or even fatal diseases were which were all linked to the work activities, maybe the job site
injuries and there were deaths, which could not have been prevented.
So, all these were taken into consideration and ISO is actually a global policy on any system
of plays and health and safety, not really on construction. So, ISO 45001 was developed,
keeping in mind all the relevant standards on safety, including OHSAS 18001 and also the
international labour organization which is ILO-OSH 2001, but still, it is not an updated
standard it is primarily a new standard.
But many of the principles developed which were already available in these standards were
also considered into ISO 45001. Now, if you see what are the main differences between ISO
standards and other standards is obviously the ISO 45001 has a high-level structure with
which it can easily include or link with ISO 9001 which is a quality standard and the ISO 14,001 which is the environmental standard and ISO 50001 which is our energy management
So, reasons for bringing in an ISO several versions of OHSAS are out there are developed
and also there needs to be a harmonization or a same language which has to be spoken by
different countries. So, as a result ISO came into existence and if you look at many of these
policies are maybe the comparison from OHSAS and ISO 45001.