Friday, 27 September 2013

Noise Hazard

What is occupational noise exposure?

Noise, or unwanted sound, is one of the most pervasive occupational health problems. It is a by-product of many industrial processes. Sound consists of pressure changes in a medium (usually air), caused by vibration or turbulence.
These pressure changes produce waves emanating away from the turbulent or vibrating source. Exposure to high levels of noise causes hearing loss and may cause other harmful health effects as well. The extent of damage depends primarily on the intensity of the noise and the duration of the exposure. Noise-induced hearing loss can be temporary or permanent. Temporary hearing loss results from short-term exposures to noise, with normal hearing returning after period of rest. Generally, prolonged exposure to high noise levels over a period of time gradually causes permanent damage.
This hearing conservation program is designed to protect workers with significant occupational noise exposures from hearing impairment even if they are subject to such noise exposures over their entire working lifetimes.
This publication summarizes the required component of OSHA’s hearing conservation program for general industry. It covers monitoring, audiometric testing, hearing protectors, training, and recordkeeping requirements.

What monitoring is required?

The hearing conservation program requires employers to monitor noise exposure levels in a way that accurately identifies employees exposed to noise at or above 85 decibels (dB) averaged over 8 working hours, or an 8-hour time-weighted average (TWA). Employers must monitor all employees whose noise exposure is equivalent to or greater than a noise exposure received in 8 hours where the noise level is constantly 85 dB.
The exposure measurement must include all continuous, intermittent, and impulsive noise within an 80 dB to 130 dB range and must be taken during a typical work situation. This requirement is performance-oriented because it allows employers to choose the monitoring method that best suits
each individual situation. Employers must repeat monitoring whenever changes in production, process, or controls increase noise exposure. These changes may mean that more employees need to be included in the program or that their hearing protectors may no longer provide adequate protection.
Employees are entitled to observe monitoring procedures and must receive notification of the results of exposure monitoring. The method used to notify employees is left to
the employer’s discretion. Employers must carefully check or calibrate instruments used for monitoring employee exposures to ensure that the measurements are accurate. Calibration procedures are unique to specific instruments. Employers should follow the manufacturer’s instructions to determine when and how extensively to calibrate the instrument.

What is audiometric testing?

Audiometric testing monitors an employee’s hearing over time. It also provides an opportunity for employers to educate employees about their hearing and the need to protect it.
The employer must establish and maintain an audiometric testing program. The important elements of the program include baseline audiograms, annual audiograms, training, and followup procedures. Employers must make audiometric testing available at no cost to all employees who are exposed
to an action level of 85 dB or above, measured as an 8-hour TWA.
The audiometric testing program followup should indicate whether the employer’s hearing conservation program is preventing hearing loss. A licensed or certified audiologist, otolaryngologist, or other physician must be responsible for the program. Both professionals and trained technicians may conduct audiometric testing.
The professional in charge of the program does not have to be present when a qualified technician conducts tests.
The professional’s responsibilities include overseeing the program and the work of the technicians, reviewing problem audiograms, and determining whether referral is necessary.
The employee needs a referral for further testing when test results are questionable or when related medical problems are suspected. If additional testing is necessary or if the employer suspects a medical pathology of the ear that is caused or aggravated by wearing hearing protectors, the
employer must refer the employee for a clinical audiological evaluation or otological exam, as appropriate. There are two types of audiograms required in the hearing conservation
program: baseline and annual audiograms.

What is a baseline audiogram?

The baseline audiogram is the reference audiogram against which future audiograms are compared. Employers must provide baseline audiograms within 6 months of an employee’s first exposure at or above an 8-hour TWA of 85 dB. An exception is allowed when the employer uses a mobile test van for audiograms. In these instances, baseline audiograms must be completed within 1 year after an employee’s first exposure to workplace noise at or above a TWA of 85 dB. Employees, however, must be fitted with, issued, and required to wear hearing protectors whenever
they are exposed to noise levels above a TWA of 85 dB for any period exceeding 6 months after their first exposure until the baseline audiogram is conducted.
Baseline audiograms taken before the hearing conservation program took effect in 1983 are acceptable if the professional supervisor determines that the audiogram is valid. Employees
should not be exposed to workplace noise for 14 hours before the baseline test or wear hearing protectors during this time period.

What are annual audiograms?

Employers must provide annual audiograms within 1 year of the baseline. It is important to test workers’ hearing annually to identify deterioration in their hearing ability as early as possible. This enables employers to initiate protective followup measures before hearing loss progresses. Employers must compare annual audiograms to baseline audiograms to determine whether the audiogram is valid and whether the employee has lost hearing ability or experienced a standard
threshold shift (STS). An STS is an average shift in either ear of 10 dB or more at 2,000, 3,000, and 4,000 hertz.

What is an employer required to do following an audiogram evaluation?

The employer must fit or refit any employee showing an STS with adequate hearing protectors, show the employee how to use them, and require the employee to wear them. Employers must notify employees within 21 days after the determination that their audiometric test results show an STS. Some employees with an STS may need further testing if the professional determines that their test results are questionable or if they have an ear problem thought to be caused or aggravated by wearing hearing protectors. If the suspected medical problem is not thought to be related to wearing hearing protection, the employer must advise the employee to see a physician. If subsequent audiometric tests show that the STS identified on a previous audiogram is not persistent, employees whose exposure to noise is less than a TWA of 90 dB may stop wearing hearing protectors. The employer may substitute an annual audiogram for the original baseline audiogram if the professional supervising the audiometric program determines that the employee’s STS is persistent. The employer must retain the original baseline audiogram, however, for the length of the employee’s employment. This substitution will ensure that the same shift is not repeatedly identified. The professional also may decide to revise the baseline audiogram if the employee’s hearing improves. This will ensure that the baseline reflects actual hearing thresholds to the extent possible. Employers must conduct audiometric tests in a room meeting specific background levels and with calibrated audiometers that meet American National Standard Institute (ANSI) specifications of SC-1969.

When is an employer required to provide hearing protectors?

Employers must provide hearing protectors to all workers exposed to 8-hour TWA noise levels of 85 dB or above. This requirement ensures that employees have access to protectors before they experience any hearing loss. Employees must wear hearing protectors:
  1. For any period exceeding 6 months from the time they are first exposed to 8-hour TWA noise levels of 85 dB or above, until they receive their baseline audiograms if these tests are delayed due to mobile test van scheduling;
  2. If they have incurred standard threshold shifts that demonstrate they are susceptible to noise; and
  3. If they are exposed to noise over the permissible exposure limit of 90 dB over an 8-hour TWA.

Employers must provide employees with a selection of at least one variety of hearing plug and one variety of hearing muff. Employees should decide, with the help of a person trained to fit hearing protectors, which size and type protector is most suitable for the working environment.
The protector selected should be comfortable to wear and offer sufficient protection to prevent hearing loss.
Hearing protectors must adequately reduce the noise level for each employee’s work environment. Most employers use the Noise Reduction Rating (NRR) that represents the protector’s ability to reduce noise under ideal laboratory conditions. The employer then adjusts the NRR to reflect
noise reduction in the actual working environment.
The employer must reevaluate the suitability of the employee’s hearing protector whenever a change in working conditions may make it inadequate. If workplace noise levels increase, employees must give employees more effective protectors. The protector must reduce employee exposures to at least 90 dB and to 85 dB when an STS already has occurred in the worker’s hearing. Employers must show employees how to use and care for their protectors and
supervise them on the job to ensure that they continue to wear them correctly.

What training is required?

Employee training is very important. Workers who understand the reasons for the hearing conservation programs and the need to protect their hearing will be more motivated to wear their protectors and take audiometric tests.
Employers must train employees exposed to TWAs of 85 dB and above at least annually in the effects of noise; the purpose, advantages, and disadvantages of various types of hearing protectors; the selection, fit, and care of protectors; and the purpose and procedures of audiometric testing.
The training program may be structured in any format, with different portions conducted by different individuals and at different times, as long as the required topics are covered.

What exposure and testing records
must employers keep?

Employers must keep noise exposure measurement records for 2 years and maintain records of audiometric test results for the duration of the affected employee’s employment. Audiometric test records must include the employee’s name and job classification, date, examiner’s name, date of the last acoustic or exhaustive calibration, measurements of the background sound pressure levels in audiometric test rooms, and the employee’s most recent noise exposure measurement.

Sunday, 22 September 2013

Emergency / Disaster Management (NFPA 1600)

Preparation of Disaster/Emergency Management Program

Following steps are required to be considered while preparation disaster/emergency management program for any organization. 

Hazard Identification, Risk Assessment, and Impact Analysis

The entity shall identify hazards, the likelihood of their occurrence, and the vulnerability of people, property, the environment, and the entity itself to those hazards.

Hazards to be considered at a minimum shall include, but shall not be limited to, the following:

  1. Natural hazards (geological, meteorological, and biological)
  2. Human-caused events (accidental and intentional)

The entity shall conduct an impact analysis to determine the potential for detrimental impacts of the hazards on conditions including, but not limited to, the following:
  1. Health and safety of persons in the affected area at the time of the incident (injury and death)
  2. Health and safety of personnel responding to the incident
  3. Continuity of operations
  4. Property, facilities, and infrastructure
  5. Delivery of services
  6. The environment
  7. Economic and financial condition
  8. Regulatory and contractual obligations
  9. Reputation of or confidence in the entity

Hazard Mitigation

The entity shall develop and implement a strategy to eliminate hazards or mitigate the effects of hazards that cannot be eliminated.
The mitigation strategy shall be based on the results of hazard identification and risk assessment, impact analysis, program assessment, operational experience, and cost-benefit analysis.
The mitigation strategy shall consider, but not be limited to, the following:
  1. The use of applicable building construction standards
  2. Hazard avoidance through appropriate land-use practices
  3. Relocation, retrofitting, or removal of structures at risk
  4. Removal or elimination of the hazard
  5. Reduction or limitation of the amount or size of the hazard
  6. Segregation of the hazard from that which is to be protected
  7. Modification of the basic characteristics of the hazard
  8. Control of the rate of release of the hazard
  9. Provision of protective systems or equipment for both cyber or physical risks
  10. Establishment of hazard warning and communication procedures
  11. Redundancy or duplication of essential personnel, critical systems, equipment, information, operations, or materials

Resource Management

The resource management objectives established shall consider, but not be limited to, the following:
  1. Personnel, equipment, training, facilities, funding, expert knowledge, materials, and the time frames within which they will be needed
  2. Quantity, response time, capability, limitations, cost, and liability connected with using the involved resources 
  3. An assessment shall be conducted to identify the resource capability shortfalls and the steps necessary to overcome any shortfalls. 
  4. A current inventory of internal and external resources shall be maintained.
  5. Voluntary donations, solicited and unsolicited, and the management thereof, shall be addressed.
  6. The need for mutual aid shall be determined and agreements established.

Mutual Aid

Mutual aid agreements shall be referenced in the applicable program plan.

Planning

  1. The program shall include, but shall not be limited to, a strategic plan, an emergency operations/response plan, a mitigation plan, a recovery plan, and a continuity plan.
  2. The strategic plan shall define the vision, mission, goals, and objectives of the program as it relates to the policy of the entity 
  3. The emergency operations/response plan shall assign responsibilities to organizations and individuals for carrying out specific actions at projected times and places in an emergency or disaster.
  4. The mitigation plan shall establish interim and long term actions to eliminate hazards that impact the entity or to reduce the impact of those hazards that cannot be eliminated.
  5. The recovery plan shall be developed using strategies based on the short-term and long-term priorities, processes,
  6. vital resources, and acceptable time frames for restoration of services, facilities, programs, and infrastructure.
  7. A continuity plan shall identify the critical and time sensitive applications, vital records, processes, and functions that shall be maintained, as well as the personnel and procedures necessary to do so, while the damaged entity is being recovered.

Common Plan Elements


  1. The functional roles and responsibilities of internal and external agencies, organizations, departments, and individuals shall be identified.
  2. Lines of authority for those agencies, organizations, departments, and individuals shall be established or identified.

Communications and Warning

  • Communications systems and procedures shall be established and regularly tested to support the program.
  • The entity shall develop and maintain a reliable capability to notify officials and alert emergency response personnel.
  • Emergency communications and warning protocols, processes, and procedures shall be developed, periodically tested, and used to alert people potentially impacted by an
  • actual or impending emergency.

The program shall address communications including, but not limited to, the following:
  1. Communication needs and capabilities to execute all components of the response and recovery plans 
  2. The inter-operability of multiple responding organizations and personnel

Operations and Procedures

  1. The entity shall develop, coordinate, and implement operational procedures to support the program.
  2. The safety, health, and welfare of people, and the protection of property and the environment under the jurisdiction of the entity shall be addressed in the procedures.
  3. Procedures, including life safety, incident stabilization, and property conservation, shall be established and implemented for response to, and recovery from, the consequences of those hazards identified. 
  4. A situation analysis that includes a damage assessment and the identification of resources needed to support response and recovery operations shall be conducted.
  5. Procedures shall be established to allow for initiating recovery and mitigation activities during the emergency response.
  6. Procedures shall be established for succession of management/government.

Logistics and Facilities

The entity shall establish logistical capability and procedures to locate, acquire, store, distribute, maintain, test, and account for services, personnel, resources, materials, and facilities procured or donated to support the program.
A primary and alternate facility capable of supporting continuity, response, and recovery operations shall be established, equipped, periodically tested, and maintained.

Training

  • The entity shall assess training needs and shall develop and implement a training/educational curriculum to support the program. The training and education curriculum shall
  • comply with all applicable regulatory requirements.
  • The objective of the training shall be to create awareness and enhance the skills required to develop, implement, maintain, and execute the program.
  • Frequency and scope of training shall be identified.
  • Personnel shall be trained in the entity’s incident management system.
  • Training records shall be maintained.
  • Exercises, Evaluations, and Corrective Actions.
  • The entity shall evaluate program plans, procedures, and capabilities through periodic reviews, testing, post incident reports, lessons learned, performance evaluations,
  • and exercises.
  • Exercises shall be designed to test individual essential elements, interrelated elements, or the entire plan(s).
  • Procedures shall be established to ensure that corrective action is taken on any deficiency identified in the evaluation process and to revise the relevant program plan.

Finance and Administration

The entity shall develop financial and administrative procedures to support the program before, during, and after an emergency or a disaster.
Procedures shall be established to ensure that fiscal decisions can be expedited and shall be in accordance with established authority levels and accounting principles. The procedures shall include, but not be limited to, the following:

  1. Establishing and defining responsibilities for the program finance authority, including its reporting relationships to the program coordinator
  2. Program procurement procedures
  3. Payroll
  4. Accounting systems to track and document costs.

Saturday, 21 September 2013

Drinking Water Quality

Drinking Water Quality In Pakistan

Several potential sources are present to contaminate drinking water. Bacterial, chemical and many other types of contamination of drinking water has been reported to be one of the most serious problems throughout the country in rural as well as urban areas. 
Such contamination is attributed to leakage of pipes, pollution from sewerage pipes due to problem within the distribution system, intermittent water supply, and shallow water tables due to human activities. A second strong source for ground water contamination in irrigated and industrial areas is chemical pollution from toxic substances from the industrial effluents, textile dyes, pesticides, nitrogenous fertilizers, arsenic and other chemicals. 

In addition, excessive monsoon rains, floods, herbicides, fungicides, untreated municipal waste, sewage breakdowns, and coastal water pollution due to waste discharges and oil spills are extremely hazardous for drinking water. For the sake of public health, it is absolutely essential 
to establish drinking water quality by strict monitoring and regularization and criteria to save the general public in Pakistan. 

in Pakistan, people use low quality water for drinking including foul smelling, bad tasting, turbid or colored water to determine that it is not suitable for drinking. The agencies responsible for monitoring of water quality perform periodic checks of the basic water parameters against certain recommended standards. 

In 1999, Hashmi & Shahab advocated for the strong need to establish standards and guidelines for quality drinking water. In 2002, the Pakistan Standards Institute compiled the preliminary standards for quality drinking water. In 2004, Pakistan Council of Research in Water Resources 
prepared a report related to water quality in Pakistan with recommendations for establishing standards. In March 2005, Health Services Academy, the Ministry of Health, Government of Pakistan in collaboration with World Health Organisation (WHO) sponsored, organised and 
conducted a 4-day workshop in Islamabad. The purpose of this workshop was to 
review current standards implemented in Pakistan for quality control of drinking water and update these standards in accordance with the quality standards of WHO. 

In this work shop, 33 representatives from the different organizations were participated including United Nations Development Program, UNICEF, Pakistan Environmental Protection Agency, PSQCA, Pakistan Council for Research in Water Resources, PINSTECH / Pakistan Atomic Energy Commission, Pakistan Council of Scientific and Industrial Research, Institute of Environmental Science and Engineering, Pakistan Standard Quality Control Authority Development 
Centre, Environmental Protection Agency-Sindh, Liaquat University of Medical and Health Sciences, Social Security Hospital, Lahore Engineering University, and Pakistan Medical and Dental Council. 

  1. Through a combination of lectures, discussions, intense work Sessions, and utilization of reading literature provided by WHO and Ministry of Health, quality standards for drinking water in Pakistan were finalized. During all sessions, a careful attention was given to the following considerations: All modifications in standards remain in correspondence with the social, cultural, geological, economic, technical and other significant conditions specific to the regional areas. 
  2. review of existing national research-based data related to drinking water quality should be conducted.
  3. The work done by individual experts and by specialists from different agencies throughout the country should be coordinated and utilized in the finalization of standards. 
  4. In addition to WHO guidelines and standards, US EPA standards, Malaysian standards, and Indian water quality standards were to be utilized for further benefits.
  5. The standards must have a long range positive impact on human health in Pakistan.
  6. Recommendations should be made based on the finalized standards for future plans of action. 

Quality Standards for Drinking Water 

1. Physical

Parameters                                                    Standard Value

Colour                                                         ≤15 TCU  
Taste                                               Non objectionable/Acceptable 
Odour                                              Non objectionable/Acceptable 
Turbidity                                                     < 5 NTU  
Total hardness as CaCO3                              < 500 mg/l   
TDS                                                           < 1000   
pH                                                               6.5 – 8.5   

2.  Chemical 

Aluminium (Al)                                          <0.2 mg/l   
Antimony (Sb)                                         <0.005 mg/l   
Arsenic (As)                                             <0.05 mg/l  
Barium (Ba)                                                0.7 mg/l
Boron (B)                                                   0.3  mg/l  
Cadmium (Cd)                                            0.01 mg/l
Chloride (Cl)                                             <250  mg/l 
Chromium (Cr)                                          <0.05 mg/l
Copper (Cu)                                                2 2 mg/l

3.  Toxic Inorganic 

Cyanide (CN)                                          <0.05 mg/l 
Fluoride (F)                                             <1.5  mg/l 
Lead (Pb)                                              <0.05  mg/l
Manganese (Mn)                                      <0.5  mg/l
Mercury (Hg)                                         <0.001 mg/l  
Nickel (Ni)                                             <0.02  mg/l  
Nitrate (NO3)                                          <50   mg/l
Nitrite (NO2)                                            <3   mg/l
Selenium (Se)                                         0.01  mg/l
Residual Chlorine                             0.2-0.5 at consumer end & 
                                                        0.5-1.5 at source 
Zinc (Zn)                                                 5.0  mg/l

4.  Organic 

Phenolic compounds (as Phenols)                            < 0.002 
Polynuclear aromatic hydrocarbons (as PAH)     0.01 ( By GC/MS method) 

5.  Radioactive 

Alpha Emitters bq/L or pCi                        0.1 
Beta emitters                                         1 1 



















Fire Science and Fire Extinguishers

Fire Since and Fire Extinguishers

What is Fire

Fire is a combustible chemical reaction between oxygen and any type of fuel resulting heat, smoke light called fire.

 

Fire Tetrahedron

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Fire is a rapid chemical reaction which starts rapidly in the presence of four basis element which are show in tetrahedron.
Oxygen
The oxidizer is a reactant in the chemical reaction of fire. In most cases, it is the ambient air, and in particular one of its components, oxygen (O2). In certain cases such as some explosives, the oxidizer and combustible are the same (e.g., nitroglycerin, an unstable molecule that has oxidizing parts in the same molecule as the oxidize able parts).
Fuel
Fuels are any materials that store potential energy in forms that can be practicably released and used as heat energy. The concept originally applied solely to those materials storing energy in the form of chemical energy that could be released through combustion but the concept has since been also applied to other sources of heat energy such as nuclear energy (via nuclear fission or nuclear fusion), as well as releases of chemical energy released through non-combustion oxidation.
Fuels are further classified in two three types depending on their physical condition or state.
  • Solid Fuel      Such as wood, coal, peat etc.
  • Liquid Fuel   Such as diesel, Gasoline, Kerosene, Coal tar, Ethanol etc.
  • Gaseous Fuel Hydrogen, Propane, Water gas, LPG, CNG, etc.
Heat
Heat is a form of energy required to start combustion reaction in various quantity for various type of fuel. Heat can be transferred by three modes.
  • Conduction
  • Convection
  • Radiation
Chemical Reaction
When fuel, oxygen and required amount of heat are met together resulting starts a chain reaction causing fire.

Portable Fire Extinguishers, Classifications and their Uses

Introduction to NFPA 

NFPA stands for National Fire Protection Association founded in 1896, NFPA grew out of that first meeting on sprinkler standards. The By laws of the Association that were first established in 1896 embody the spirit of the codes and standards development process.
“The purposes of the Association shall be to promote the science and improve the methods of fire protection and prevention, electrical safety and other related safety goals; to obtain and circulate information and promote education and research on these subjects; and to secure the cooperation of its members and the public in establishing proper safeguards against loss of life and property.”
The NFPA mission today is accomplished by advocating consensus codes and standards, research, training, and education for safety related issues. NFPA’s National Fire Codes are administered by more than 250 Technical Committees comprised of approximately 8,000 volunteers and are adopted and used throughout the world.
NFPA Fire Classification
Class A
Class A fires are ordinary materials like burning paper, lumber, cardboard, plastics etc.
Class B
Class B fires are involve flammable or combustible liquids such as gasoline, kerosene, and common organicsolvents used in the chemical industry.
Class C
Class C fires involve energized electrical equipment, such as appliances, switches, panel boxes, power tools,hot plates and stirrers. Water can be a dangerous extinguishing medium for class C fires because of the risk of electrical shock unless a specialized water mist extinguisher is used.
Class D
Class D fires involve combustible metals, such as magnesium, titanium, potassium and sodium as well aspyrophoric organometallic reagents such as alkyllithiums, Grignards and diethylzinc. These materials burn at high temperatures and will react violently with water, air, and/or other chemicals. Handle with care!!
Class K
Class K fires are kitchen fires. This class was added to the NFPA portable extinguishers Standard 10 in 1998. Kitchen extinguishers installed before June 30, 1998 are "grandfathered" into the standard.
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Basic Types of Fire Extinguishers

1.     Water extinguishers
Water fire extinguishers are suitable for class A (paper, wood etc.) fires, but not for class B, C and D fires such as burning liquids, electrical fires or reactive metal fires. In these cases, the flames will be spread or the hazard made greater! Water mist extinguishers are suitable for class A only.

2.     Dry chemical extinguishers (DCP)

DCP fire extinguishers are useful for either class A B C or class B C fires (check the label) and are your best all-around choice for common fire situations. They have an advantage over CO2 and "clean agent" extinguishers in that they leave a blanket of non-flammable material on the extinguished material which reduces the likelihood of reignition. They also make a terrible mess, but if the choice is a fire or a mess, take the mess Note that there are two kinds of dry chemical extinguishers:
  • Type BC fire extinguishers contain sodium or potassium bicarbonate.
  • Type ABC fire extinguishers contain ammonium phosphate.
Proper planning can avoid situations where you might have to make a choice between extinguisher types. Ensure that the extinguishers closest to your computers or aircraft are of an appropriate type (if local fire codes permit) and that workers in those areas are trained on when and how to use them. And remember, if your computer or airplane is fully engulfed in flames or a person is in danger, then possible added damage from an ABC extinguisher is moot.
3.      CO2 (carbon dioxide) extinguishers
Carbon dioxide fire extinguisher are for class B and C fires. They don't work very well on class A fires because the material usually reignites. CO2 extinguishers have an advantage over dry chemical in that they leave behind no harmful residue. That makes carbon dioxide a good choice for an electrical fire involving a computer or other delicate instrument. Note that CO2 is a bad choice for a flammable metal fires such as Grignard reagents, alkyllithiums and sodium metal because CO2 reacts with these materials. COextinguishers are not approved for class D fires! Carbon dioxide extinguishers do not have pressure gauges because carbon dioxide is a condensable gas. Thus, pressure does not tell you how much agent remains in the cylinder. Instead, the extinguisher should have a tare (empty) weight stamped on it. To determine the amount of carbon dioxide remaining in the extinguisher, subtract the tare weight from the current weight.
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4.      Metal/Sand Extinguishers
Metal and sand fire extinguisher are for flammable metals (class D fires) and work by simply smothering the fire. The most common extinguishing agent in this class is sodium chloride, but there are a variety of other options. You should have an approved class D unit if you are working with flammable metals.
I. Sodium chloride (NaCl) works well for metal fires involving magnesium, sodium (spills and in depth), potassium, sodium/potassium alloys, uranium and powdered aluminum. Heat from the fire causes the agent to cake and form a crust that excludes air and dissipates heat.
II. Powdered copper metal (Cu metal) is preferred for fires involving lithium and lithium alloys. Developed in conjunction with the U.S. Navy, it is the only known lithium firefighting agent which will cling to a vertical surface thus making it the preferred agent on three dimensional and flowing fires.
III. Graphite-based powders are also designed for use on lithium fires. This agent can also be effective on fires involving high-melting metals such as zirconium and titanium.
IV. Specially-designed sodium bicarbonate-based dry agents can suppress fires with most metal alkyls, pyrophoric liquids which ignite on contact with air, such as triethylaluminum, but do not rely on a standard BC extinguisher for this purpose.
V. Sodium carbonate-based dry powders can be used with most Class D fires involving sodium, potassium or sodium/potassium alloys. This agent is recommended where stress corrosion of stainless steel must be kept to an absolute minimum.
5.     Halotron-I extinguisher
Like carbon dioxide units, are "clean agents" that leave no residue after discharge. Halotron I is less damaging to the Earth's ozone layer than Halon 1211 (which was banned by international agreements starting in 1994). This "clean agent" discharges as a liquid, has high visibility during discharge, does not cause thermal or static shock, leaves no residue and is non-conducting. These properties make it ideal for computer rooms, clean rooms, telecommunications equipment, and electronics. These superior properties of Halotron I come at a higher cost relative to carbon dioxide.
6.     Hydrofluorocarbon (HCFC)
FE-36TM (Hydrofluorocarbon-236fa or HFC-236fa) is another "clean agent" replacement for Halon 1211. This DuPont-manufactured substance is available commercially in Clean guard® extinguishers. The FE-36 agent is less toxic than both Halon 1211 and Halotron I. In addition, FE-36 has zero ozone-depleting potential; FE-36 is not scheduled for phase-out whereas Halotron I production is slated to cease in 2015. A 100% non-magnetic Clean Guard model is now available (see the warning box below).

Friday, 20 September 2013

Safety, Health and Environmental Issues in My Country


This blog relates to the fire and safety issues in Pakistan. Actually work place safety and health issues are the major problems of every developed and underdeveloped country including Pakistan. In the UK accidents kill over 8000 people a year. Over six million people are injured, many of them seriously. More than 2 million people suffer from work related ill health. Same as the fire incidents in Pakistan kill 16,500 people and leave 164,000 injured or disabled every year across the country.
 

Let’s have a look on some major fire accidents happened in Pakistan in last few days.

Fire at Lahore Development Authority (LDA)
A fire erupted at the LDA plaza situated on Lahore’s Edgerton road killed eight persons, and many injured. The fire erupted around noon started on the 7th and 8th floor of the building and rapidly engulfed three more floors.
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A man reportedly fell from the seventh floor of the 13-story building while escaping the fire and died on the spot. Similarly, two others jumped out in hope of escaping but later succumbed to injuries at the hospital.
School bus fire kills 18 children in Gujrat
At least 18 children and a teacher were killed when their school bus caught fire in Gujrat. Blast caused by a spark as driver of the dual-fuel van tried to switch from gas to petrol. It was also reported that driver also kept petrol in a plastic bottle as reserve fuel. This accident was happened when school vehicle was a few kilometers away from school. The age of children’s were 5 to 15 years. The driver fled and left the van in flames.
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Fire in a garment factories of Karachi and Lahore
Garment factories in the Pakistani cities of Karachi and Lahore caught fire on 11 September 2012. The fires occurred in a textile factory in the western part of Karachi and in a shoemaking factory in Lahore.
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The fires are considered to be the most deadly and worst industrial factory fires in Pakistan's history, killing 257 people and seriously injuring more than 600.
 

Costs of accidents

Before starting to fine the root cause of these accident let’s have a look on the cost of the accident. Majorly there are two types of accident costs.
1. Direct costs of an accident
Direct costs are those costs that are accrued directly from the accident. They are quite easy to calculate the damages, repair/maintenance, and include the medical costs incurred and the compensation payments made to the injured workers. Direct costs are usually insurable by businesses.
2. Indirect costs of an accident
Indirect costs are the less obvious consequences of an accident that can be coasted. While the indirect costs created by accidents are hidden, they too must be paid from profits from the sale of products. They are more difficult to calculate and tend not to be insured. Indirect costs include:
  1. Physical and mental stress on the victims and their families.
  2. The cost of damage to materials or equipment involved in the accident.
  3. Bad impression in market.
  4. The cost of wages paid to the supervisor for time spent on activities related to the accident. This includes caring for the injured, investigating the accident, and supervising the activities necessary to resume the operation of business. All of these activities will disrupt the supervisor's productivity;
  5. Costs associated with instructing, training, and repositioning employees in order to resume production. In some cases, it might even be necessary to hire a replacement with all the associated hiring costs.
  6. Medical costs paid by the employer that are not covered by the insurance. This may include treatment facilities, personnel, equipment and supplies.
  7. Cost of managers and clerical personnel investigating and processing claim forms and related paperwork, telephone calls, interviews, etc.
  8. Wage costs due to decreased productivity once the injured employee returns to work. This is due to restricted movement or nervousness/cautiousness on the part of the injured employee and time spent discussing the accident with other employees etc.
  9. Costs brought about from any enforcement action following the accident such as prosecution fines and costs of imposed remedial works.

Root causes of these accident

There are several factors that exacerbated the situation leading to the loss of life. Mainly there are two main reasons of accidents. One is unsafe acts and second is unsafe conditions. Some detail of these two major factors are given below.
  • The lack or unavailability of fire gadgets such as fire and smoke detectors, alarms, automatic control system, fire hydrant system and fire extinguishers etc.
  • Congested traffic routes which causes delayed the first responding agencies like fire fighters, rescue, and medical etc.
  • Failure of Law and enforcement agencies.
  • Taking Shortcuts: To complete the job faster and more efficient we take decisions, but do time savers ever risk your own safety, or that of other crew members? Short cuts that reduce your safety on the job are not shortcuts, but an increased chance for injury.
  • Over Confidence: It’s good to be confident, but overconfidence attitude can leads toward accident.
  • Faulty electric equipment’s or faulty flexible cords
  • Incompetence
  • Lack of knowledge and trainings
  • Ignoring Safety Procedures
  • Starting a Task with Incomplete Instructions
  • Faulty or inappropriate equipment’s
  • Failing to use the appropriate protective equipment’s
  • Unsafe working procedures
  • Unavailability of escape roots
These accidents are not the isolated events and in my point of view main causes of these accidents was only negligence. This negligence may be from the owner of factory, law and enforcement agencies, person who was driving the van. In our miserable state which is operating without any proper enforcement of safety regulations and law these civilians will be entrapped and their families have to bear all these situations until above said conditions were not eliminated. Our country should take prompt measures to ensure the safety and security of its people. Millions of lives lost because due to negligence of some people reflect the failure of the state’s machinery. Now what matter is, how hard is it to prioritise the invest in the services that matter related to the public safety in normal life as well as on their work place.