compiled case studies

Case Study 1

Control of Hazardous Energy In Shipyard Employment

Case History

On October 16, 2005, a worker onboard a fish-

processing vessel was cleaning a vat used to process

fish paste. The augers at the bottom of the vat

suddenly started up, trapped the worker's feet and

legs, and drew them into the machinery. It took

coworkers two hours to free her from the machinery

and another half day for a helicopter to arrive and

airlift her off the vessel. The helicopter flew the

employee to a hospital in Anchorage, Alaska, where

her legs were amputated below the knees.

Example: Auger

Analysis & Preventive Measures

While the switch providing power to the vat and its augers was off, nobody rendered the

equipment inoperative through the use of a lockout or tags-plus application. Additionally,

there was no signage (e.g., danger tag) posted to indicate hazardous conditions could arise

if the equipment became energized - - such as "Do Not Start," "Do Not Open," "Do Not

Close," "Do Not Energize," or "Do Not Operate." This serious incident was preventable if an

effective program was in place and a means of protection applied before starting work.

Case Study 2

Confined Space Entry City Water Worker Dies When Overcome by Natural Gas Vapors

In a Confined Space in Ohio

INTRODUCTION

On July 1, 1985, an industrial meter reader employed

by a mid-sized city in Ohio began his workday as usual at

7:30 a.m. He did not return to the garage at quitting time

(4:00 p.m.) and was found face down in a meter vault at

6:45 p.m.

OVERVIEW OF EMPLOYER'S SAFETY PROGRAM

This city has a population of 235,000 an employs approximately 2,500 permanent and

temporary workers. There are six major departments, one of which is the Department of Public

Service. The Department of Public Service has several bureaus, including the Public Utilities

Bureau. The Public Utilities Bureau has four divisions: Utility Services, Water Supply, Water

Pollution Control, and Water Distribution. The victim was employed by the Water Distribution

Division. This division employs 145 full-time and up to 25 seasonal workers. There are six

industrial meter readers, two of which are assigned to reding meters at any one time. (Meter

readers work individually.)

A deputy to the mayor is the designated safety officer and 90 percent of his time is

spent handling labor relations and the remainder of his time is spent dealing with safety-related

issues.

SYNOPSIS OF EVENTS

On July 1, 1985, route assignments were received by the meter readers at 7:30 a.m. The

victim (a 42-year-old meter reader) was assigned 76 accounts to be read that day. The victim

had traded the original route assigned for a route with which he was unfamiliar. Industrial

meters may be located in basements, at ground level, or in meter vaults and any one route may

include all of these meter locations. The victim did not return to the garage at the usual quitting

time of 4 p.m. This is not unusual because workers are occasionally late. At 5 p.m. when the

victim still had not returned and he did not respond to dispatch calls, the police were notified.

At 6:45 p.m. a passerby reported that the meter reader was down in a manhole and a fire

rescue unit was dispatched to the accident site. The victim was found face down in the vault.

The vault had approximately 4 1/2 inches of water in it. Resuscitation efforts were unsuccessful

and the victim was pronounced dead at 9:31 p.m.

The victim had read 33 out of the 76 assigned meters when he reached the accident

site. His supervisor felt that this should have taken until approximately 1:30 p.m. The victim was

familiar with this vault, having seen it at the time of installation; however, this was the first

reading of this newly installed meter. The vault was installed in May 1985 and was inspected for

compliance with city regulations at that time. During this inspection, it was noted that the

manhole cover did not have holes required for sufficient ventilation. The manhole cover was to

be checked for compliance at this meter reading. No holes were present in the cover. According

to the employee's supervisor, the victim may have had difficulty in removing the cover because

the hook used to pull the lid open was straightened out and a sledge hammer was lying next to

the manhole.

The vault (a two-piece, precast concrete structure---15 feet by 9 feet by 8 feet) contains

large water lines and an industrial water meter. No other utility services used this vault. An

investigation of the vault was undertaken by the local coroner's office. The investigation

revealed a faint odor of natural gas. The local gas company was notified about a possible leak. It

was later determined that a leak was present in a nearby line and the gas was then turned off.

After the vault was determined safe for entry, the interior of the vault was inspected; however,

no signs were present that indicated that the victim may have slipped or fallen. Since natural

gas was suspected in this accident, the vault was further tested. On July 3, 1985, the gas line

was turned on and the vault tested. The atmosphere in the vault was periodically tested. It was

eventually determined that oxygen (17 percent), methane (15 percent), and carbon monoxide

(

RECOMMENDATIONS/DISCUSSION

Recommendation #1: The city should develop and implement a comprehensive safety

program. The Division of Water Distribution should have a documented safety program that

identifies safe work practices to be followed. This program should include recognition of

potential hazards.

Discussion: The city has no safety program and no written safety policy exists. Additionally, the

Division of Water Distribution does not have a written safety policy or manual. Safety training is

the responsibility of supervisory personnel and is limited to on-the-job training. The Division of

Water Distribution is in the process of starting a new safety program for all employees

consisting of four hours of initial training and a monthly, one-hour follow-up. This course needs

to be supplemented by a written safety manual.

Recommendation #2: The employer should develop comprehensive policies and procedures

for confined space entry.

Discussion: All employees of the city who work in confined spaces should be aware of potential

hazards, possible emergencies, and specific procedures to be followed, prior to entering a

confined space. These procedures should minimally include:

1. Air quality testing to assure adequate oxygen supply, adequate ventilation, and the

absence of all toxic air contaminants.

2. Employee and supervisory training in the selection and usage of respiratory equipment.

3. Development of site-specific working procedures and emergency access and egress

plans.

4. Emergency rescue training.

Air quality was not tested prior to entry into the vault. Although oxygen/air quality monitoring

devices are now provided for meter readers, training is necessary in proper usage and

calibration of these devices. Respirators are now available for emergency use. Respirator

training, fitting, and proper maintenance procedures should be completed by all personnel who

may be required to use a respirator on the job. Medical evaluations of employees should be

conducted to determine if they are physically able to perform the work while using a respirator.

Immediate response to an emergency situation could prevent such fatalities. A full-time

dispatcher is employed by the division. It would benefit the city to incorporate routine call-in

procedures (indicating location, entrance time, and exit time) before confined space entry. (The

employer should make full use of the resources they have available.) Guidance concerning

proper procedures for confined space entry are discussed in DHEW NIOSH Publication No. 80-

106, Working in Confines Spaces.

Recommendation #3: Vault manhole covers should have holes for ventilation.

Discussion: The Division of Water Distribution requires that manhole covers have holes for

ventilation. The manhole cover at this accident site did not have the required holes. Although

re-inspection was to take place at the time of this meter reading, this vault should not have

passed inspection when initially installed and the victim should have been instructed not to

enter the vault unless the proper manhole cover was in place.

Recommendation #4: Employers should assign employees tasks that at commensurate with

their physical capabilities

Discussion: The job of reading meters can involve strenuous physical activity. The victim had a

history of medical problems. This medical history apparently was not taken into consideration

when the victim was initially hired as a meter reader.

Case Study 3

Basic Electrical Safety Electrician Electrocuted in Airport

SYNOPSIS OF ACCIDENT

Workplace Premise:

Airport (Manhole), Virginia

Work Activity:

A 24-year-old male electrician was electrocuted when he inadvertently contacted a

2,300-volt, 6.6-amp conductor. The incident occurred while the victim was working inside a

manhole splicing a conductor. The victim and a co-worker were part of a six-person crew

assigned to install a new lighting system at an airport.

Nature of Accident:

Death as Electrocution

DESCRIPTION OF ACCIDENT

The victim entered the manhole through a 24-inch-diameter manway opening and

descended a metal ladder attached to the inside of the 5-foot-square by 7-foot-deep

concrete manhole. The victim removed a pair of insulated side (wire) cutters from his

tool belt to prepare the de-energized taxiway lighting conductor for splicing. He cut a

size 8 AWG conductors which was hanging over a rung of the metal ladder without

determining whether or not the circuit was energized. The conductor, which was part of

the energized runway lighting circuit, separated into two pieces. The energized end

came in contact with the back of the victim's right hand. Current passed through the

victim's right hand and exited his right thigh at the point where it was in contact with

the grounded metal ladder.

Prior to the incident, the victim and co-worker had completed connections for the

permanent taxiway lights in four separate manholes. The victim entered the fifth

manhole via a 24-inch-diameter man way, descended a metal ladder attached to the

inside of the manhole, and positioned himself on the ladder facing the circuit

conductors. He removed a pair of insulated side (wire) cutters from his tool belt and,

without using the amp probe to test for current in the conductors, cut a hanging

conductor. The conductor, which was part of the energized runway lighting circuit, came

in contact with the back of the victim's right hand after being cut in half. Current passed

through the victim's right hand and exited his right thigh at the point of contact with the

grounded ladder.

The co-worker was standing near the top of the manhole observing the victim. After

realizing what had occurred, he knocked the victim off the ladder away from the

energized conductor. He entered the manhole and carried the victim out. The co-worker

then notified the electrician/foreman, who was in the area but working on a separate

task. The foreman summoned airport emergency rescue personnel who arrived within 3

minutes after being contacted. The rescue squad provided advanced cardiac life

support and transported the victim to the local hospital where he was pronounced dead

45 minutes after the incident occurred.

KEY FINDING/OBSERVATIONS

The electrician is not skilled to do his duty. There was no safe work procedure

established.

The electrician should test first if he was working with live wires and turn off the

main source of electricity.

There is failure to manage works.

LEARNING POINTS

Employers should establish required procedures for the protection of employees

exposed to electrical hazards and provide worker training in the recognition and

avoidance of such hazards.

Employers should conduct initial jobsite surveys to identify all hazards associated

with each specific jobsite, and develop specific methods of controlling the

identified hazards.

Risk analysis or assessment must be done in all kinds of job, simple or

complicated.

Case Study 4

Fall Protection Falling Accident in Aircraft


Workplace Premise:

Airbus A321-200, Dubai airport

Work Activity:

A Russian air stewardess was

injured when she fell out of an aircraft

which was struck by a catering truck as it

prepared to depart from its gate

at Dubai airport on Monday morning.

The aircraft received "quite some"

damage as a result of the collision with the

catering ground vehicle and a replacement

aircraft was sought, resulting in the flight

being delayed by 14.5 hours.

Nature of Accident:

Falling Accident and Failure to manage work


The Airbus A321-200, operated by Ural Airlines, was preparing to depart for

its flight from Dubai to the Russian city of Perm when a ground

catering truck impacted the tail of the aircraft causing the flight attendant to fall

out of the aircraft through the open door, landing on the tarmac 4 meters below.

The operator of the catering truck, Emirates Flight Catering, issued the following

statement regarding the incident: At 0455 Monday morning, 17th February, an

Emirates Flight Catering hi-loader made impact with the Ural Airlines aircraft

operating as flight 6806 at Dubai International Airport. Our vehicle was starting

the positioning process to service the rear galley when the incident occurred.

Unfortunately one of the airlines flight attendants was hurt during the incident

and received medical attention


The operator of the flight catering truck is not proficient to follow and manage

his job responsibility.

The stewardess should not stand near the door of the aircraft knowing that she

might fall out because absence of iron bars or grills to hold on for promoting

safety.

There is inadequate safety trainings and briefings to effectively promote safety

awareness among workers.

LEARNING POINTS

Importance of ensuring catering trucks is trained and competent.

Importance of ensuring any machinery such as catering truck and aircraft are

safe and without risk for workers

Importance of conducting risk assessment to identify and implement control

measures which include proper safe work procedure for the aircraft and airport

workers

Risk analysis or assessment must be done in all kinds of job, simple or

complicated.

Case Study 5

Barricades and Scaffolds One Killed, Three Injured in Scaffold Accident (December 8, 1998)

A 29-year-old hod carrier died and three co-workers were injured when they fell from

the fourth story of a pump house building that was under construction at a reservoir.

The hod carrier and others had been spraying fireproof insulation onto the structural

steel frame of the building. They used a rolling tower scaffold to gain access to the structural

steel overhead.

Putlogs (types of trusses) had been added to the sides of the rolling tower scaffold, and

an extension platform had been built there. This platform was used to reach the outer side of

the structural steel.

On this day, a supervisor said a guardrail was needed on the scaffold. The hod carrier

joined three co-workers on the extension platform to help install the guardrail. Their combined

weight caused the scaffold to tip. They were all thrown to the concrete deck 44 feet below.

The scaffold had not been engineered for the extension platform. No counterweights,

anchorage, or bracing were used. Neither the hod carrier nor his co-workers were wearing

personal fall protection. The scaffold and platform had been constructed using parts from

different manufacturers.

Preventive Measures:

Cal/OSHA investigated this accident and made the following recommendations.

Employers should:

Ensure that scaffolds are assembled according to the manufacturers recommendations.

If locally built, they must be properly designed and engineered.

Ensure that no extensions or auxiliary parts are added to scaffolds unless designed and

approved by an engineer.

Ensure that workers follow safe work practices when constructing scaffolds.

Ensure that scaffold load limits given by the manufacturer or engineer are not exceeded.

Case Study 6

Fire Safety and Fire Code Jaipur Oil Depot Fire (2009)

The Jaipur Oil Terminal fire took place on 29 October, 2009 at 7:30 PM at Indian Oil

Corporations oil depot, at Sitapura Industrial area, Jaipur. There were nearly 12 casualties and

over 200 injuries. The blaze continued to rage out of control for 11 days. The incident occurred

when petrol was being transferred from the Indian Oil Corporation's oil depot to a pipeline.

There were at least 40 IOC employees at the terminal, when it caught fire with an explosion.

The Incident: Schematic Layout

Standard Operating System Likely Sequence

1. Ensure MOV and HOV are closed 1. MOV opened first

2. Reverse the position of Hammer Blind

Valve

2. Hammer Blind Valve opened

3. Open the HOV 3. Leakage started

4. Open MOV (initially inching operation

to establish no leakage from Hammer

Blind Valve body)

Source of Ignition:

outside the installation. The Non flame proof electrical fittings in administration block located

in the south western direction of the terminal or Spark during starting of the vehicle at the

installation are probable cause of source of fire.

The Incident: Major Timeline

No. Activity Time (Hours)

1 Sealing of Tank Lines, Valves etc. for PLT Before 17:50

2 Tank Handing Over by Pipelines to Marketing 17:50

3 Start of Hammer Blind Reversal Work After 17:50

4 Start of MS Spillage 18:10

5 Rescue of Operation Officer 18:20-18:24

6 First Communication Outside the Terminal 18:24

7 Sounding of Siren 18:30

8 Formation of Vapor Cloud Across the Terminal 18:10-19:30

9 Vapor Cloud Explosion 19:30

The Incident: Possible Scenario

Scenario 1:

Opened by someone anytime between the previous blinding operations.

Scenario 2: MOV opened accidentally when the blind was being reversed (due to

spurious signal or manually).

Amongst the two Scenarios, Scenarios-I, that the MOV was in open condition before the

start of the hammer blind reversal job, appear to be more likely.

The Incident: Contributing Factors

Non-availability of one of the shift workman, who was supposed to be on duty.

Control room remaining unmanned due to above.

Absence of specific written-down procedures for the works to be undertaken and,

therefore, reliance on practices.

Opening of the HOV before completion of hammer blind reversal operation.

Not checking the MOV for its open/close status and not locking it in closed position.

Not using proper protective equipment while attempting rescue work.

Initiation of the critical activity after normal working hours, leading to delay in response

to the situation.

Non-availability of second alternate emergency exit.

Proximity of industries, institutes, residential complexes etc. close to the boundary wall.

Case Study 7

Industrial Hygiene Exposure Assessment to Suggest the Cause of Sinusitis Developed in

Grinding Operations Utilizing Soluble Metalworking Fluids


Workplace Premise:

Donguk Park et al. Korea National Open University

Work Activity:

A worker who grinded the inner parts of camshafts for automobile engines using water-

soluble metalworking fluid (MWF) for 14 years was diagnosed with sinusitis. We postulated that

the outbreak of sinusitis could be associated with exposure to microbes contaminated in water-

soluble MWF during the grinding operation. To suggest responsible agents for this outbreak,

quantitative exposure assessment for chemical and biological agents and prevalence of work-

related respiratory symptoms by questionnaire were studied

Nature of Accident:

Exposure assessment to suggest the cause of sinusitis developed in grinding operations

utilizing soluble metalworking fluids


A grinding operation worker at an automobile engine plant was physician-diagnosed

with sinusitis. His main job was to grind the inner parts of camshafts for automobile

engines using water-soluble metalworking fluids (MWF). He has conducted only this

work since he was employed on March 1988. He has no disease history including

respiratory diseases. Workers Union also claimed that many workers might have similar

work-related symptoms and requested an epidemiological study to find the cause of

sinusitis Health effects that have been associated with exposure to metalworking fluids

(MWF) include dermatitis, respiratory health effects, and increased mortality form a

variety of cancers. Although exposure to MWFs is associated with respiratory diseases

such as asthma and hypersensitivity pneumonitis (HP)

Workers handling water-soluble MWF in this workplace could be exposed to several

chemical and biological agents that might associate with the development of respiratory

diseases. Our study hypothesized that the outbreak of sinusitis might be associated with

exposure to micro-biologically contaminated MWF mist generated during grinding

operations. This assumption was taken from the results of several studies conducted in

environment other than MWF using workplaces, which determined that most cases of

sinusitis were caused by bacterial and fungal infections4-10). The ultimate goal of this

study is to suggest the causative agent that can relate to the development of sinusitis

based on industrial hygiene investigation. The specific objectives are 1) to assess

exposure to chemical and biological agents that could associate with the development

of sinusitis in grinding operations utilizing water-soluble MWF and 2) to compare the

prevalence of the nasal cavity symptoms among operations.


In particular, two workers using water-soluble MWF in grinding operation were

exposed to higher than 2 mg/m3. It indicates that grinding operators handling soluble

MWFs could be defined as similar group with homogeneous exposure characteristics.

Substantial evidences that could adversely affect the

respiratory systems of workers were not detected but there are exposure to bacteria,

fungi and endotoxin.

LEARNING POINTS

The range of personal exposure to MWF oil mist measured in grinding operation

where one worker physician-diagnosed with sinusitis had grinded the inner parts

of camshafts for automobile engines using water-soluble MWF for 14 years

greatly exceeded 0.5 mg/m3 of NIOSH-REL

Exposure to bacteria, fungi and endotoxin during grinding operations were found

to be higher than the results reported by several other studies on respiratory

effects.

Repeated exposure to MWF mistincluding microbes in grinding operation may

cause respiratory diseases like sinusitis or at least may increase to the

development of sinusitis

Case Study 8

Hazard Communication and Chemical Safety

Barton Solvents - Static Spark Ignites Explosion inside Flammable

Liquid Storage Tank


Workplace Premise:

Barton Solvents Wichita facility in Valley Center, Kansas

Work Activity:

Company was transferring pump bulk

flammable into storage tanks when suddenly

explosion happened. Eleven residents and one

firefighter received medical treatment.

It destroyed the tank farm and interrupted

Bartons business

Nature of Accident:

Explosion inside Flammable Liquid Storage

Tank


On July 17, 2007, at about 9 a.m., an explosion and fire occurred at the Barton

Solvents Wichita facility in Valley Center, Kansas.

The incident triggered an evacuation of Valley Center (approximately 6,000

residents); destroyed the tank farm; and significantly interrupted Bartons

business.

The initial explosion occurred soon after the tank farm supervisor started the

transfer of the final compartment of a tanker-trailer containing VM&P naphtha

into a 15,000 gallon above-ground storage tank


The CSB determined that several factors likely combined to produce the initial explosion:

The tank contained an ignitable vapor-air mixture in its head space.

Stop-start filling, air in the transfer piping, and sediment and water (likely

present in the tank) caused a rapid static charge accumulation inside the VM&P

naphtha tank.

The tank had a liquid level gauging system float with a loose linkage that likely

separated and created a spark during filling.

The MSDS for the VM&P naphtha involved in this incident did not adequately

communicate the explosive hazard.

LEARNING POINTS

Request additional manufacturer guidance

Add an inert gas to the tank head space

Modify or replace loose linkage tank level floats

Add an anti-static agent

Reduce flow (pumping) velocity

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