Response Time Index (RTI) is a measure of thermal sensitivity of a sprinkler’s activation. It indicates how quickly the sprinkler responds to the heat from a fire. RTI is calculated by using the operating time, operating temperature, air temperature, air velocity, and conductivity factor of the sprinkler. RTI is independent of the gas velocity but depends on the properties of the sprinkler head such as mass, specific heat capacity andsurface area of the thermal sensing element. RTI is used to classify sprinklers into fast response or standard response categories.

References:The Basics of Sprinkler Thermal Characteristics | NFPA;Sprinkler Characteristics According to NFPA 13 - Fire Protection …;Response time index (RTI) - Oil and Gas Drilling Glossary;RESPONSE TIME INDEX OF SPRINKLERS - Department of Building Environment …

Spontaneous combustion is the exception to the requirement of a combustible material, an oxidizing agent, and an ignition source for combustion to take place. Spontaneous combustion is a phenomenon in which a material can ignite without any external heat or flame, due to a chemical reaction within the material that generates enough heat to reach the ignition temperature. Spontaneous combustion can occur in certain materials that are prone to self-heating, such as oily rags, hay, coal, and compost. Spontaneous combustion is a type of smoldering combustion, which is a slow, low-temperature, flameless form of combustion.References:

• Fire Protection Handbook, 20th Edition, Volume 1, Chapter 2, Section 2.2.1.11
• NFPA 921: Guide for Fire and Explosion Investigations, 2021 Edition, Section 4.3.12

The correct answer is A. Type I construction consists of structural members of approved noncombustible or limited combustible materials with specified fire resistance ratings for exterior bearing walls of 3 or 4 hours. This is the highest level of fire resistance among the five types of construction defined by NFPA 220: Standard for Types of Building Construction.Type I construction is typically used for high-rise buildings made of concrete and protected steel12

20 years.

According to NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, 2020 edition, fast response sprinklers are those that have a response time index (RTI) of 50 (m·s)^(1/2) or less.These sprinklers are designed to activate faster than standard response sprinklers in the event of a fire, and they are typically used in light hazard, ordinary hazard, and residential occupancies1

NFPA 25 requires initial testing of representative samples of fast response sprinklers after 20 years from the date of manufacture, and subsequent testing every 10 years thereafter. The testing involves removing a minimum of four sprinklers or 1% of the total number of sprinklers per individual sprinkler sample, whichever is greater, and sending them to a recognized testing laboratory. The laboratory will perform a plunge test, which measures the time it takes for the sprinkler to operate when exposed to a specified air temperature.The test results will indicate whether the sprinklers meet the acceptance criteria or need to be replaced123

References:

• NFPA 25: Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems1
• Sprinkler System Inspections, Testing, and Maintenance Frequencies Explained | NFPA4
• Sprinkler Testing on Quick Response Sprinklers: What You Need to Know2
• NFPA 25 ITM Quick Reference Guide - hillgrp.com3

OSHA regulation 1910.110 addresses storage and handling of liquefied petroleum gas (LPG). This regulation covers the general requirements for the design, construction, installation, operation, inspection, and maintenance of LPG systems, including containers, piping, valves, fittings, regulators, burners, and appliances. The regulation also specifies the safety precautions and procedures for the prevention of fire and explosion hazards involving LPG. The regulation applies to all employers who store, handle, or use LPG in their workplaces.References:

• OSHA: 1910.110 - Storage and handling of liquefied petroleum gases1
• Nebula Safety: Storage & Handling of Liquefied Petroleum Gases (LPGs)2

Fire alarm systems audible appliances ratings are usually stated as a sound pressure level (SPL) at 10 ft (3.05 m) from the appliance. The SPL is measured in decibels (dB) and indicates the loudness of the sound produced by the appliance. The SPL at 10 ft (3.05 m) is used as a standard reference point for comparing different audible appliances and for designing fire alarm systems to meet the required audibility levels.References:

• NFPA 72: National Fire Alarm and Signaling Code, 2019 Edition, Section 18.4.3.11
• Fire Protection Handbook, 20th Edition, Volume 1, Chapter 7, Section 7.8.2.12

Class A roof coverings are the most effective in preventing the spread of fires from flying brands. Flying brands are burning embers or pieces of combustible material that are carried by the wind and can ignite other combustible materials or structures. Class A roof coverings are tested to withstand severe fire exposure from simulated fire sources, such as large burning brands, and do not produce flying brands themselves. Class A roof coverings include materials such as asphalt shingles, metal sheets, clay or concrete tiles, slate, and some types of synthetic membranes12. References:

• Class A, B, and C Roof Ratings - UL
• Fire-Resistant Roofs - Fire Safe Marin

The background color used from the source to the outlets of a nitrous oxide medical gas system is blue. This is the standard color coding for nitrous oxide cylinders and pipelines in medical gas pipeline systems12. The color coding helps to identify the gas type and prevent accidental misconnections or cross-contamination3. The color coding also indicates the pressure and flow characteristics of the gas system4. References:

• Colour coding of copper pipes in Medical gas pipeline system according …
• Doc 177 20 Medical Gas Cylinders Colour Coding - EIGA
• Medical Gas Coding Color Chart & Explanation - Bay Corporation
• Medical gases Health Technical Memorandum 02-01: Medical gas pipeline …

According to NFPA 13, Table 17.4.2.1 (a), the maximum distance between hangers for an automatic fire sprinkler system for a threaded lightwall steel pipe of 2 in. diameter is 10 ft. This is done to ensure that there are not long stretches of unsecured piping that could sag, leak, or break. The distance between hangers may vary depending on the type of pipe, the type of hanger, and the seismic design category of the building.References:NFPA 13, Table 17.4.2.1 (a);Hangers and Support of Sprinkler System Piping | NFPA | NFPA.

The duration of required fire flow in public supply systems depends on the type of occupancy, construction, and exposure of the building, as well as the availability and reliability of the water supply. According to NFPA 1, Fire Code, Table 18.4.5.1.2, the minimum duration of fire flow for most occupancies ranges from 1 to 4 hours, with some exceptions for high-rise buildings, health care facilities, and special hazards. The fire flow duration is intended to provide enough water for fire suppression and exposure protection until the fire is under control or extinguished.References: NFPA 1, Fire Code, 2023 Edition, Section 18.4.5.1.2 and Table 18.4.5.1.2; NFPA Fire Protection Handbook, 21st Edition, Chapter 9, Section 9.2.2.

The minimum width of a doorway in a means of egress to accommodate a person in a wheelchair is 32 inches (813 mm).This is based on the requirements of the Americans with Disabilities Act (ADA) and the International Building Code (IBC), which both specify that doors in a path of egress and doors on an accessible route must have a clear opening width of at least 32 inches (813 mm)12. This width allows enough space for a person in a wheelchair to maneuver through the doorway without difficulty. A wider doorway may be preferable for some types of wheelchairs or other assistive devices, but 32 inches (813 mm) is the minimum standard for accessibility and safety.References:DECODED: Calculating the Egress Width of Door Openings - I Dig Hardware;Digital Codes.

The phenomenon of convergence cluster formation in human fire behavior was identified in 1979 in a university dormitory fire. This phenomenon refers to the tendency of people to gather in groups near familiar exits or locations during a fire, rather than seeking alternative escape routes1. This can result in congestion, delay, and increased risk of injury or death2. The university dormitory fire occurred at the Providence College in Rhode Island, where 10 students died and 40 were injured. The fire started in a trash chute and spread to the upper floors. Many students tried to escape through the main stairwell, which became blocked by smoke and flames. Some students jumped from the windows, while others remained trapped in their rooms. The fire revealed the lack of fire safety education, fire drills, and fire protection systems in the dormitory3. References:

• Human Behavior in Fire Emergencies
• Human Behavior in Fire: Understanding Human Behavior for Better Fire Safety Design
• Providence College Dormitory Fire

Dipping and coating processes using flammable or combustible liquids pose a significant fire and explosion hazard and should be isolated from other operations, materials, or occupancies by location, fire walls, or operational procedures. Location refers to the physical separation of the process from other areas by distance or barriers. Fire walls are fire-resistance-rated assemblies that prevent the spread of fire from one side to the other. Operational procedures are rules or guidelines that regulate the conduct of the process and its personnel, such as limiting the amount of flammable or combustible liquids in use, controlling ignition sources, and providing adequate ventilation.

References: NFPA 34: Standard for Dipping, Coating, and Printing Processes Using Flammable or Combustible Liquids, 2021 Edition, Section 4.21; Fire Protection Handbook, 20th Edition, Volume 1, Chapter 8, Section 8.3.12.

1:NFPA 34: Standard for Dipping, Coating, and Printing Processes Using Flammable or Combustible Liquids2:Fire Protection Handbook, 20th Edition, Volume 1, Chapter 8

The data of a pre-incident plan should be evaluated after an incident, as part of the post incident critique or analysis. This is to assess the accuracy, completeness, and usefulness of the pre-incident plan, and to identify any changes or updates needed based on the lessons learned from the incident.Evaluating the pre-incident plan after an incident can also help improve the emergency response performance and the fire safety management of the site.References:123

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The correct answer is B.Safety is one of the criteria for selecting the power source for driving fire pumps, according to NFPA 20, Chapter 9.1.1.11. Reliability, adequacy, and economy are the other criteria mentioned in the same chapter. Efficiency, adaptability, and ecology are not explicitly stated as criteria in NFPA 20, although they may be considered as secondary factors in some cases.

1:Pump Installation: Everything About Electric and Diesel Driven Fire …

Computers and other information technology equipment are particularly susceptible to heat, steam, and combustion products, which can damage their sensitive components, cause data loss or corruption, and impair their functionality.Therefore, fire protection for IT equipment should consider the potential sources of heat, steam, and combustion products, such as electrical faults, flammable liquids, dust accumulation, water-based sprinklers, or smoke from adjacent areas, and implement appropriate measures to prevent, detect, and suppress fires, as well as to minimize the exposure of IT equipment to these hazards1234.References:Standard for the Fire Protection of Information Technology Equipment;Fire Protection of Computer Rooms—Legal Obligations and Best Practices - ISACA;Exploring Requirements for Information Technology Equipment;Demystifying IT room protection requirements - Consulting.

According to NFPA 101: Life Safety Code, 2018 Edition, the travel distance limit for a new unsprinklered educational occupancy is 175 ft. (53 m). This is the maximum distance that an occupant has to travel from any point within the building to reach an exit or exit access door. The travel distance limit for a new sprinklered educational occupancy is 250 ft. (76 m).These limits are based on the assumption that the building has at least two exits or exit access doors from each room or space12

References:

• NFPA 101: Life Safety Code, 2018 Edition, Chapter 14
• Deco DeD - I Dig Hardware

The answer is C. Human factor plays a significant role in most industrial fire and explosion losses.According to a study by Allianz Global Corporate & Specialty (AGCS), human error is the cause of 80% of all industrial accidents, including fires and explosions1. Human error can include mistakes, negligence, violations, or sabotage. Some examples of human errors that can lead to fires and explosions are:

• Improper handling or storage of flammable or combustible materials
• Failure to follow safety procedures or regulations
• Lack of training or supervision
• Poor maintenance or inspection of equipment or machinery
• Ignoring or disabling alarms or warning systems
• Smoking or using open flames near hazardous areas
• Intentional or accidental ignition of explosives or incendiaries

To prevent or reduce the impact of human errors, industrial facilities should implement effective risk management strategies, such as:

• Providing regular and adequate training and education for workers and managers
• Establishing and enforcing clear and consistent safety policies and rules
• Conducting thorough and frequent audits and inspections
• Installing and maintaining reliable fire protection systems and equipment
• Developing and practicing emergency response and evacuation plans
• Encouraging a positive safety culture and communication among all stakeholders

Two-dimensional models are not a common type of road tunnel fire models. Most road tunnel fire models are either one-dimensional, zone, or field models. One-dimensional models use a simplified approach to describe the fire and smoke behavior along the tunnel axis, assuming uniform conditions across the tunnel cross-section. Zone models divide the tunnel into two or more zones, each with uniform properties, and apply mass and energy conservation equations to each zone. Field models use computational fluid dynamics (CFD) to solve the governing equations for mass, momentum, energy, and species transport in a three-dimensional grid, capturing the spatial and temporal variations of the fire and smoke phenomena. Two-dimensional models are rarely used for road tunnel fire simulations, as they cannot account for the complex three-dimensional effects of fire and ventilation in tunnels.

References:Design Fires in Road Tunnels | The National Academies Press;CFD Modelling of Fire Ventilation in Road Tunnels - Academia.edu;Findings of the International Road Tunnel Fire Detection Research …1

According to the Consumer Products Safety Commission (CPSC), the most common type of fabric used on upholstered furniture is cellulosic. Cellulosic fabrics are made from natural fibers derived from plants, such as cotton, linen, rayon, and hemp. Cellulosic fabrics account for about 51% of the total fabric weight used on upholstered furniture in the United States1. Cellulosic fabrics are popular because they are soft, comfortable, breathable, and versatile. However, they are also highly flammable and can contribute to the spread of fire if ignited2. Therefore, the CPSC has established a flammability standard for upholstered furniture that requires cellulosic fabrics to pass a smolder resistance test3. References:

• Upholstered Furniture Business Education | CPSC.gov
• Fire Fighting Foams - Chemguard
• Standard for the Flammability of Residential Upholstered Furniture

According to NFPA 72, the maximum sound pressure level (SPL) for a fire alarm system is 110 dBA at the minimum hearing distance from the audible appliance1.However, this limit can be exceeded if the sound pressure level measured 2 000 mm above floor level is not more than 100 dBA2. Sound pressure level is a measure of the intensity of sound at a given point in space, expressed in decibels (dB). The higher the SPL, the louder the sound.For comparison, a normal conversation is about 60 dB, a jet engine is about 140 dB, and a gunshot is about 160 dB3.References:Sound Pressure Levels - NFPA;NFPA fire alarm sound level - EntirelySafe.com;Subsection 907.5 - Occupantnotification systems - Casetext;How Loud Is a Fire Alarm In Decibels (dB)? With Noise Comparison Chart;The Ontario Building Code | Audibility of Alarm Systems.

Class 3 unstable reactive gas is defined as a material that in itself is capable of detonation or explosive decomposition or reaction at normal temperatures and pressures with a strong initiating source or if heated under confinement. This class of gas readily undergoes violent chemical change at elevated temperatures and pressures.

References:NFPA 55: Compressed Gases and Cryogenic Fluids Code, 2016 Edition, Section 3.3.51.14.3;International Fire Code, 2015 Edition, Appendix E, Section E102.1.1

According to NFPA 230: Standard for the Fire Protection of Storage, 2015 Edition, building codes should limit the size of an unsprinklered facility used for the processing and storage of Municipal Solid Waste (MSW) built of type V construction to 7,500 ft2 (697 m2). This is based on the assumption that the MSW has a heat release rate of 18,000 Btu/ft2-min (200 kW/m2) and a fire growth rate of 0.046 min-1.Type V construction is defined as a type of construction in which the structural elements, exterior walls, and interior walls are of any materials permitted by the code123

References:

• NFPA 230: Standard for the Fire Protection of Storage
• 5 Types of Construction per the IBC | Building Code Trainer
• 2.4 MUNICIPAL SOLID WASTE LANDFILLS - U.S. Environmental Protection Agency

The correct answer is C. A thermocouple is a temperature measurement device that consists of a pair of wires of different metals or alloys welded together at a point to form a junction. The junction is exposed to the temperature to be measured, while the other end of the wires is connected to a reference junction at 0°C. The thermocouple produces a voltage difference between the two junctions that depends on the temperature difference.This voltage difference can be calibrated to give the temperature in degrees using a thermocouple table or a formula123

A Class I standpipe system provides 2 1/2 in. (65 mm) hose connections at designated locations in a building for use by the fire department. A Class I standpipe system is intended to supply water for fire fighting operations by trained personnel using hoses of 1 1/2 in. (40 mm), 1 3/4 in. (45 mm), or 2 in. (50 mm) nominal diameters. A Class I standpipe system is required to deliver a minimum flow rate of 250 gpm (946 L/min) at a minimum residual pressure of 100 psi (6.9 bar) at the most remote hose connection.References:

• NFPA 14: Standard for the Installation of Standpipe and Hose Systems, 2019 Edition, Section 3.3.4.11
• Fire Protection Handbook, 20th Edition, Volume 1, Chapter 8, Section 8.2.1.12