Heat-Sensing Fire Detectors

Heat-sensing Fire Detectors

Heat-sensing fire detectors shall be installed in all areas where assessed as per standards or by the authority having jurisdiction. The relationship between heat and temperature must be understood if heat-sensing detectors are to be applied properly.
Heat is energy and is quantified in terms of an amount, usually British thermal units (Btu) or Joules (J). Temperature is a measure of the quantity of heat in a given mass of material and is measured as an intensity, quantified in terms of degrees Farenheit or Celsius.
The majority of the heat flowing into a heat detector is from the hot gases that comprise the ceiling jet. This is called convective heat transfer. A much smaller portion of the heat absorbed by a heat detector is transferred by radiation, a process called radiant heat transfer.
Heat detectors operate on one or more of three different principles. These operating principles are categorized as fixed temperature, rate compensation, and rate-of-rise. Each principle has its performance advantages and can be used in either a spot-type device or a line-type device.
Most heat detectors are devices that change in some way when the temperature at the detector achieves a particular level, or a set point, as in a fixed-temperature type. Other detectors respond to the rate of temperature change, as in a rate-of-rise heat detector.
Heat detectors are available in two general types: spot-type, which are devices that occupy a specific spot or point; and line-type, which are linear devices that extend over a distance, sensing temperature along their entire length.
A number of different technologies can be used to detect the heat from a fire, including
the following:

1. Expanding bimetallic components
2. Eutectic solders
3. Eutectic salts
4. Melting insulators
5. Thermistors
6. Temperature-sensitive semiconductors
7. Expanding air volume
8. Expanding liquid volume
9. Temperature-sensitive resistors
10. Thermopiles

The designer must be careful not to confuse the terms, type and principle with technology, which
is the method used to achieve heat detection.

General

Before installation of Fire detectors some performance related objectives should be describe the purpose of the detector, placement and the intended response of the fire alarm control unit to the detector activation.
The performance objective of a fire detection system is usually expressed in terms of time and the size fire the system is intended to detect, measured in kilowatts (kW) or British thermal units per second (Btu/sec). Typically, the fire alarm system designer does not establish this criterion. It is usually obtained from the design documentation prepared by the designer responsible for the strategy of the structure as a whole. Where a prescriptive design is being provided, this requirement is fulfilled by stating in the design documentation that the design conforms to the prescriptive provisions.
A fire protection strategy is developed to achieve those goals. General performance objectives are developed for the facility. These general objectives give rise to specific performance objectives for each fire protection system being employed in the facility. Consequently, the performance objectives and criteria for the fire alarm system are part of a much larger strategy that often relies on other fire protection features, working in concert with the fire alarm system to attain the overall fire protection goals for the facility.
In the performance-based design environment, the designer uses computational models to demonstrate that the spacing used for automatic fire detectors connected to the fire alarm system will achieve the objectives established by the system, by showing that the system meets the performance criteria established for the system in the design documentation.
Consequently, it is imperative that the design objectives and performance criteria to which the system has been designed are clearly stated in the system documentation.

Temperature Classification

The performance of a heat detector depends on two parameters: its temperature classification and its time-dependent thermal response characteristics. Traditionally, the temperature classification has been the principal parameter used in selecting the proper detector for a given site.
An additional objective is to select a detector that will be stable in the environment in which it will be installed.

Color Coding

Heat-sensing fire detectors of the fixed-temperature or rate-compensated, spot-type shall be classified as to the temperature of operation and marked with a color code in accordance with Table given below

Exception: Heat-sensing fire detectors where the alarm threshold is field adjustable and that are marked with the temperature range.
Spot-type heat detectors are currently the most widely used type of heat detector for general purpose use.
Not all heat detector manufacturers use this color code. Some manufacturers simply provide a label on the side or bottom of the detector. When the unified color coding of heat detectors is used, it facilitates inspections, making it possible to identify the temperature rating of a ceiling-mounted heat detector while standing on the floor. The color code for heat detectors is very similar to that used for sprinkler heads, as per NFPA 13.
Manufacturers also provide this information in their data sheets for each type of heat detector. The commercial availability of solid state thermal sensors and analog/ addressable fire alarm system control units has made possible the development of analog/addressable heat detectors. These detectors permit the designer to adjust the alarm threshold temperature at the fire alarm control unit and select a unique threshold temperature based on an analysis of the compartment and the fire hazard. A color code would be meaningless for this technology and consequently is waived. Clearly, when analog/addressable technology is used, an alternative means for facilitating inspection should be in place.

Integral Heat Sensors

A heat-sensing fire detector integrally mounted on a smoke detector shall be listed or approved for not less than 15 m (50 ft) spacing.
The linear space rating is the maximum allowable distance between heat detectors. The linear space rating is also a measure of the heat detector response time to a standard test fire where tested at the same distance. The higher the rating, the faster the response time. This Code recognizes only those heat detectors with ratings of 15 m (50 ft) or more.
The customary spacing of smoke detectors is 9.1 m (30 ft), and because smoke detectors are primarily considered to be fulfilling an early warning role, the heat detector, if deemed a necessary addition to the smoke detector, should be sufficiently sensitive to provide a response before the fire has grown to an excessive size. In order for the heat sensor portion of the detector to fulfill this expectation, it must have a 15-m (50-ft) spacing factor.

Marking

Heat-sensing fire detectors shall be marked with their listed operating temperature.
The marking of the heat detector should be with both the temperature rating and its thermal response coefficient (TRC).
The response of a heat detector is determined by two factors: its temperature rating and the speed with which it can absorb heat from the surrounding air. The temperature rating is easily measured and the requirement for marking the detector with the temperature set point has existed for many years. The second factor is TRC. The research needed to develop a method for quantifying TRC is under way. Until a verified value for the TRC for each make and model heat detector is available, our ability to predict when that heat detector will operate in relation to the development of a fire is limited and imprecise. Consequently, the lack of a TRC limits the use of such heat detectors in performance-based designs.
Some researchers have used the response time index (RTI) as a measure of the thermal response of a heat detector [Alpert, 1972; Evans and Stroup, 1986]. RTI is determined by means of a plunge test that was originally designed to test the response characteristics of sprinkler heads. The plunge test uses a simulated ceiling jet velocity of 1.5 m/sec (5.0 ft/sec). Other researchers have raised questions regarding this measurement, because heat flow from the ceiling jet to a detector is proportional to ceiling jet velocity [Brozovski, 1989;Heskestad and Delichatsios, 1989]. Because the spacing between heat detectors is often much greater than the spacing between sprinkler heads, the jet velocities normally encountered at the heat detectors are often an order of magnitude smaller than those encountered at the sprinklers. Therefore, using RTI as a measure of heat detector sensitivity presumes a much larger fire and could introduce important inaccuracies. Consequently, a TRC for heat detectors
derived from a test specifically designed for the purpose is necessary.
The adoption of the concept of a TRC presumes the development of a test method to determine the coefficient. When such a test becomes available, it will become part of the listing evaluation for heat detectors. Because the test is still in development, a requirement for marking the detector with its TRC was removed from this edition.

Location

The location stipulated takes maximum benefit of the ceiling jet produced by a fire. Because the occurrence of a ceiling jet causes the hot combustion product gases to flow outward and away from the fire plume center line, a ceiling location provides for the maximum flow across the detector and the maximum speed of response to a growing fire.
Spot-type heat-sensing fire detectors shall be located on the ceiling not less than 100 mm (4 in.) from the sidewall or on the sidewalls between 100 mm and 300 mm (4 in. and 12 in.) from the ceiling.
In compartments equipped with heat detection, spot-type heat detectors must be located on the ceiling at a distance 100 mm (4 in.) or more from a vertical side wall, or on the side wall between 100 mm (4 in.) and 300 mm (12 in.) from the ceiling, measured to the top of the detector.

The ceiling location derives the maximum benefit from the upward flow of the fire plume and the flow of the ceiling jet beneath the ceiling plane. The best currently available research data support the existence of a dead air space where the walls meet the ceiling in a typical room. This dead air space extending 100 mm (4 in.) in from the wall and 100 mm (4 in.) down from the ceiling. Consequently, the Code excludes detectors from those areas. As the ceiling jet approaches the wall, its velocity declines. Lower ceiling jet velocities result in slower heat transfer to the detector and, therefore, a retarded response. The prudent designer will keep detectors further from the wall than the 100 mm (4 in.) minimum distance.

In the case of solid joist construction, detectors shall be mounted at the bottom of the joists.
The definition of the term joist must be inferred from the definition of solid joist construction, found under Ceiling Surfaces in subsection 3.3.24. Joists are solid projections, whether structural or not, extending downward from the ceiling, that are more than 100 mm (4 in.) in depth and are spaced on 0.9 m (3.0 ft) centers or less. The commonly encountered 50 mm , 250 mm (2 in, 10 in.) rafter installed on 400 mm (16 in.) centers supporting a roof deck is typical of solid joist construction.
The structural component commonly called abar-joistis actually an open web beam. If the upper web member of an open web beam is less than 100 mm (4 in.) deep, the beam is ignored. If it is more than 100 mm (4 in.) deep, it is called either a joist or a beam, depending on the center-to-center spacing.
The narrow spacing between joists [usually approximately 380 mm (15 in.) for joists on 400 mm (16 in.) centers] creates air pockets. These air pockets have two effects on the flow of the ceiling jet. First, the air pockets tend to slow the ceiling jet; second, the air pockets force the ceiling jet to flow across the bottoms of the joists. Because the dominant flow regime of the ceiling jet will be along the bottoms of the joists, requires that heat detectors be placed on the bottoms of joists rather than up in the pockets between them. This placement puts the detectors in the region of maximum ceiling jet flow.

In the case of beam construction where beams are less than 300 mm (12 in.) in depth and less than 2.4 m (8 ft) on center, detectors shall be permitted to be installed on the bottom of beams. A definition of beam must be inferred from the definition of beam construction found under Ceiling Surfaces. Beams are effectively defined as solid projections, whether structural or not, extending downward from the ceiling, that are more than 100 mm (4 in.) in depth and are spaced on centers of more than 0.9 m (3.0 ft). In the context of the Code, the principal distinction between a joist and a beam is the center-to-center spacing.
The installation of heat detectors on the beam bottoms only when the beams are less than 300 mm (12 in.) deep, and only when the beams are on centers of less than 2.4 m (8 ft). If the beams are more than 300 mm (12 in.) deep or if they are spaced more than 2.4 m (8 ft) apart, the detectors must be placed on the ceiling surface between the beams.
Finally, the only permitted location for spot-type heat detectors is at or in close proximity to the ceiling plane. There is no research to provide guidance for detector placement in areas without ceilings. By inference, if there is no ceiling in the hazard area on which to locate heat detectors, then heat detection cannot be installed in compliance with the prescriptive requirements of the Code
Line-type heat detectors shall be located on the ceiling or on the sidewalls not more than 500 mm (20 in.) from the ceiling.
In the case of solid joist construction, detectors shall be mounted at the bottom of the joists.
In the case of beam construction where beams are less than 300 mm (12 in.)
In depth and less than 2.4 m (8 ft) on center, detectors shall be permitted to be installed on the
bottom of beams.
Where a line-type detector is used in an application other than open area protection, the manufacturer’s installation instructions shall be followed.

Temperature

Detectors having fixed-temperature or rate-compensated elements shall be selected in accordance with table given above for the maximum expected ambient ceiling temperature. The temperature rating of the detector shall be at least 11 C (20 F) above the maximum expected temperature at the ceiling.
Detectors should be selected to minimize this temperature difference in order to minimize response time. However, a heat detector with a temperature rating that is somewhat in excess of the highest normally expected ambient temperature is specified in order to avoid the possibility of premature operation of the heat detector to non-fire conditions.

Spacing

In addition to the special requirements for heat detectors that are installed on ceilings with exposed joists, reduced spacing also could be required due to other structural characteristics of the protected area, such as possible drafts or other conditions that could affect detector operation.

Smooth Ceiling Spacing

The number of detectors required is a function of the spacing factor,S, of the chosen detector.
The spacing is established through a series of fire tests conducted in the listing evaluation by the qualified testing laboratory listing the detector. The spacing is an approximation of the relative sensitivity of the detector.
The spacing derived from the fire tests relates heat detectors to the response of a specially chosen 71.1 C (160 F) automatic sprinkler head. The fire test room has a ceiling height of 4.8 m (15 ft, 9 in.) above the floor and has no airflow. The test fire is situated at the center of a square array of the test sprinkler heads, installed on 3 m 3 m (10 ft 10 ft) centers.
This places the center line of the test fire 2.2 m (7.07 ft) from the test sprinklers.
Heat detectors are mounted in a square array that is centered about the test fire with increased spacings. The fire is located approximately 0.9 m (3.0 ft) above the floor and consists of a number of pans of an ethanol/methanol mixture yielding an output of approximately 1200 kW (1138 Btu/sec). The height of the test fire and the fire area are adjusted to produce a time versus temperature curve at the test sprinklers that falls within the envelope established for the test and causes the activation of the test sprinkler at 2 minutes 10 seconds. The greatest detector spacing that produces an alarm signal before a test sprinkler actuates is the listed spacing for the heat detector.
Heat detector performance is defined relative to the distance at which it could detect the same fire that fused the test sprinkler head in 2 minutes 10 seconds. For example, a heat detector installed on a 15.2 m 15.2 m (50 ft 50 ft) array receives a 15.2 m (50 ft) listed spacing if it responds to the test fire just before the test sprinkler head operates.
It is important to keep in mind that the listed spacing for a heat detector is a lumped parameter, a number of variables, including fire size, fire growth rate, ambient temperature, ceiling height, and TRC are lumped into a single parameter called listed spacing. The listed spacing is sufficiently accurate to compare two heat detectors to each other, but it cannot be used to predict when a given detector will respond, except in the context of the fire test. Outside the context of the listing test, the listed spacing is only a relative indication of the detector thermal response.
Maximum linear spacing on smooth ceilings for spot-type heat detectors are determined by full-scale fire tests. These tests assume that the detectors are to be installed in a pattern of one or more squares, each side of which equals the maximum spacing as determined in the test. The detector to be tested is placed at a corner of the square so that it is positioned at the farthest possible distance from the fire while remaining within the square. Thus, the distance from the detector to the fire is always the test spacing multiplied by 0.7 and can be calculated.
Once the correct maximum test distance has been determined, it is valid to interchange the positions of the fire and the detector. The detector is now in the middle of the square, and the listing specifies that the detector is adequate to detect a fire that occurs anywhere within that square—even out to the farthest corner.
In laying out detector installations, designers work in terms of rectangles, as building areas are generally rectangular in shape. The pattern of heat spread from a fire source, however, is not rectangular in shape. On a smooth ceiling, heat spreads out in all directions in an ever-expanding circle. Thus, the coverage of a detector is not, in fact, a square, but rather a circle whose radius is the linear spacing multiplied by 0.7.

With the detector at the center, by rotating the square, an infinite number of squares can be laid out, the corners of which create the plot of a circle whose radius is 0.7 times the listed spacing. The detector will cover any of these squares and, consequently, any point within the confines of the circle.
So far this explanation has considered squares and circles. In practical applications, very few areas turn out to be exactly square, and circular areas are extremely rare. Designers deal generally with rectangles of odd dimensions and corners of rooms or areas formed by wall intercepts, where spacing to one wall is less than one-half the listed spacing. To simplify the rest of this explanation, the use of a detector with a listed spacing of 9.1 m 9.1 m (30 ft 30 ft) should be considered. The principles derived are equally applicable to other types.

One of the following requirements shall apply:

1. The distance between detectors shall not exceed their listed spacing, and there shall be detectors within a distance of one-half the listed spacing, measured at a right angle, from all walls or partitions extending to within 460 mm (18 in.) of the ceiling.
2. All points on the ceiling shall have a detector within a distance equal to 0.7 times the listed spacing (0.7S).

For irregularly shaped areas, the spacing between detectors shall be permitted to be greater than the listed spacing, provided the maximum spacing from a detector to the farthest point of a sidewall or corner within its zone of protection is not greater than 0.7 times the listed spacing.

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.

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.

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. A 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

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.

 

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. CO₂ extinguishers 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.

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-36^TM (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).