Firefighter 2 Ch-15

Natural gas is used in houses, businesses, and as a fuel for motor vehicles. Natural gas is a versatile and clean-burning fuel that is commonly used for heating homes and water, cooking, and generating electricity in residential and commercial buildings. It is also used as a fuel for vehicles, either in compressed natural gas (CNG) or liquefied natural gas (LNG) form, providing a cleaner alternative to traditional gasoline or diesel fuels. Additionally, natural gas is used in industries for various purposes such as heating, powering machinery, and as a raw material for chemical production.

Water is the most commonly used agent to extinguish structure fires because it is widely available, cost-effective, and has excellent heat-absorbing properties. Water can quickly cool down the fire, reducing the temperature below the ignition point and suffocating the flames. It is also effective in suppressing the release of flammable vapors. Additionally, water is non-toxic and does not leave behind any harmful residue, making it a safe and environmentally friendly choice for firefighting.

Fire load and material involved are factors in hoseline selection because different types of fires require different types of hoses. The fire load refers to the amount of combustible material present in the fire, while the material involved refers to the specific type of material burning. These factors determine the amount of water flow and pressure needed to effectively extinguish the fire. Choosing the correct hoseline based on the fire load and material involved ensures that firefighters can efficiently and safely combat the fire.

Class B fires involve flammable and combustible liquids and gases. This includes fires caused by substances such as gasoline, oil, propane, and alcohol. These fires can be extinguished using foam, carbon dioxide, or dry chemical extinguishers.

The first-due engine company is responsible for the initial response to a situation, and the company officer plays a crucial role in assessing the situation. They are trained to quickly evaluate the scene, gather information, and make decisions based on their assessment. This assessment includes factors such as the type of incident, potential hazards, available resources, and the overall safety of the crew and public. The company officer's assessment determines the initial actions taken by the first-due engine company, such as initiating firefighting operations, requesting additional resources, or establishing command.

The factors that dictate stream selection are the fire situation and the capabilities of the nozzle being used. This means that the decision on which stream to use is based on the specific circumstances of the fire, such as its size, location, and intensity, as well as the type of nozzle available and its ability to deliver the appropriate amount and type of water or firefighting agent. The water source, experience of firefighters, value of the structure, number of firefighters, number of bystanders, and length of hoseline may all be important considerations in firefighting, but they do not directly dictate the selection of the stream.

A wide-angle fog stream can protect firefighters from radiant heat. This type of stream creates a fine mist that can absorb and dissipate heat effectively, forming a barrier between the firefighters and the heat source. The wide angle of the stream allows for better coverage and protection, ensuring that the heat is dispersed over a larger area. This helps to minimize the risk of burns and injuries to the firefighters, making the wide-angle fog stream an effective pattern for protection against radiant heat.

The question asks for a method that is NOT used to determine the exact cargo. Placards, manifests, and bills of lading are all commonly used methods to determine the exact cargo. However, taste or touch is not a reliable method for determining the exact cargo as it is not a standard practice and can be dangerous or ineffective in identifying the contents of a cargo.

The color of the hoseline is the least likely factor to consider in hoseline selection. Factors such as fire conditions, volume of water needed for extinguishment, and the number of firefighters available for advancing hoselines are all more important considerations when selecting a hoseline. The color of the hoseline is typically not a significant factor in its performance or effectiveness in fighting fires.

An increase in intensity of sound or fire issuing from a relief valve indicates that the pressure inside the vessel is rising to dangerous levels. This suggests that the vessel is overheating and the pressure is reaching a point where it may cause a rupture.

The solid stream provides the greatest reach because it is a concentrated and powerful stream of water that can travel a longer distance compared to the other streams. It is able to maintain its shape and force over a longer distance, making it effective for reaching targets that are farther away.

When pressure vessels containing flammable liquids are heated by direct flame contact, a Boiling Liquid Expanding Vapor Explosion (BLEVE) can occur. This happens when the heat causes the liquid inside the vessel to rapidly boil and turn into vapor, creating a significant increase in pressure. If the pressure exceeds the vessel's capacity, it can cause the vessel to rupture or burst, leading to a violent explosion.

Preservation of evidence is not a first concern at a flammable gas incident. In such situations, the immediate priority is to ensure the safety of individuals by eliminating ignition sources and evacuating the area downwind and immediately around the break. Preserving evidence may be important for investigations after the incident, but it is not the primary concern when dealing with the immediate risks and dangers associated with flammable gas.

The combination nozzle is able to project water in a range of patterns. This type of nozzle typically has adjustable settings that allow for different spray patterns, such as a straight stream, a wide fog, or a narrow fog. It is versatile and can be used for various purposes, making it an ideal choice when different patterns of water projection are required.

In the event of a flammable gas incident involving a supply line, it is important to contact the Utility Company immediately. They are responsible for the distribution and maintenance of gas supply lines, and have the expertise and resources to handle such situations efficiently and safely. They can quickly assess the situation, shut off the gas supply if necessary, and take appropriate measures to prevent any further damage or danger. Contacting the Utility Company ensures that the incident is reported to the right authority and that prompt action is taken to mitigate the risks associated with the flammable gas incident.

Propane is a main type of liquefied petroleum gas (LPG). LPG is a flammable hydrocarbon gas that is commonly used as fuel for heating, cooking, and vehicles. Propane is a byproduct of natural gas processing and petroleum refining. It is stored and transported in its liquid form under pressure, which allows for easy handling and storage. Propane is widely used due to its high energy content, clean combustion, and versatility in various applications.

Closing at least one lane of traffic in addition to the incident lane is a guideline for working in traffic at bulk transport vehicle fires. This helps to create a safe work zone for emergency responders and minimizes the risk of accidents or injuries. By closing an additional lane, it provides a buffer zone between the incident scene and moving traffic, reducing the chances of vehicles colliding with emergency personnel or equipment. This guideline prioritizes the safety of both emergency responders and motorists on the road.

Applying foam is the most often used method for controlling flammable liquid fires because foam can quickly smother the fire and prevent the oxygen from reaching the fuel source, thereby extinguishing the flames. Foam also helps to cool down the fire and prevent re-ignition. This method is commonly used in industries where flammable liquids are present, such as oil refineries and chemical plants, as foam is highly effective in suppressing these types of fires.

When controlling Class B fires, approaches to the storage vessels exposed to the fire should be made at a 45-degree angle to the tanks. This angle allows firefighters to maintain a safe distance from the fire while still being able to effectively apply extinguishing agents. Approaching at a 45-degree angle also helps to prevent the fire from spreading to adjacent tanks or structures. This approach angle provides a balance between safety and effectiveness in controlling Class B fires.

Converting water to steam is critical for heat absorption because when water is converted into steam, it absorbs a significant amount of heat energy. This process, known as vaporization, requires the input of heat energy to break the intermolecular bonds between water molecules and convert them from a liquid state to a gaseous state. This absorption of heat allows steam to carry and transfer thermal energy, making it an important component in various heating systems and industrial processes.

Incidents involving both CNG and LPG distribution systems are most often caused by excavation equipment striking underground pipes. This is because excavation work can damage the pipes, leading to leaks or ruptures in the distribution systems. This can result in dangerous situations, as both CNG and LPG are highly flammable and can pose a significant risk if released into the environment. It is important to exercise caution and follow proper procedures when conducting excavation work near these distribution systems to prevent accidents and ensure safety.

A solid stream pattern has limited capability for cooling hot gases because it is a concentrated, uninterrupted stream of water that does not break apart into smaller droplets. This means that the water does not have as much surface area to absorb heat from the hot gases, resulting in less effective cooling. In contrast, fog streams, whether wide-angle, narrow-angle, or medium-angle, break the water into smaller droplets, increasing the surface area and enhancing the cooling capacity.

When dealing with Class B fires, which involve flammable liquids and gases, it is important to avoid standing in pools of fuel or runoff water. This is because these liquids can spread the fire and increase the risk of injury. By avoiding standing in these areas, firefighters can minimize their exposure to the fire and reduce the chances of accidents or injuries.

Natural gas is odorless, making it difficult to detect in case of a leak. To ensure safety, a very distinctive odor is added to natural gas by the utility companies. This odor, often described as a rotten egg smell, helps individuals to easily detect any gas leaks and take necessary precautions.

When the original Incident Commander has successfully organized the incident and progress is being made towards stabilization, the chief officer may choose to assume another role. This means that they can delegate their responsibilities as the Incident Commander to someone else and take on a different role that is needed at the scene. This allows for the efficient management of resources and ensures that the incident continues to be handled effectively.

LPG (liquefied petroleum gas) is a highly flammable substance that can form explosive mixtures with air. The correct answer is between 1.5 and 10% because LPG becomes explosive when its concentration in the air falls within this range. Concentrations greater than 10% are too rich to support combustion, while concentrations below 1.5% are too lean to sustain an explosion. Therefore, the range between 1.5 and 10% represents the critical concentration at which LPG poses a significant explosion risk.

The company officer of the first-arriving engine company usually assumes command of a small interior fire incident. This is because the first-arriving engine company is typically responsible for initiating fire suppression activities and establishing command at the scene. The company officer, as a higher-ranking member of the fire department, has the authority and experience to effectively manage the incident and coordinate the actions of the responding personnel.

An LPG leak will produce a visible cloud of vapor that hugs the ground because LPG (liquefied petroleum gas) is heavier than air. This means that it tends to sink and accumulate in low-lying areas, creating a dense cloud close to the ground.

Class B fuels must never be flushed down storm drains or into sewers because they can cause environmental pollution and pose a risk to public health and safety. These fuels can contaminate water sources, soil, and air, leading to potential fires, explosions, and other hazardous situations. Proper disposal methods, such as recycling or using designated waste management systems, should be followed to ensure the safe handling of Class B fuels.

Natural gas is explosive in concentrations between 5 and 15% in air. This means that if the concentration of natural gas in the air falls within this range, it can potentially ignite and cause an explosion. Concentrations below 5% or above 15% are not considered explosive. It is important to be aware of these concentration levels to ensure safety when working with or around natural gas.

In emergency situations where lives are at stake, the first-arriving engine company will take immediate action to save one or more lives, even if there are not enough firefighters on the scene to form a rapid intervention crew (RIC). This means that they will not wait for assistance or the formation of a RIC before proceeding with the rescue. The priority is to save lives, and if bystanders are available and willing to assist in the rescue, the first-arriving engine company can utilize their help. They do not need direct orders from the fire chief to proceed.

The techniques of approaching and controlling leaks or fires involving vehicles are the same as for storage vessels. This means that the methods used to handle and manage leaks or fires in vehicles are similar to those used for storage vessels. It implies that firefighters and emergency responders can apply their knowledge and experience in dealing with storage vessel incidents to effectively handle similar situations involving vehicles.

When using water as a cooling agent to control Class B fires in burning storage tanks, it is important to direct the water above the level of the contained liquid. This is because applying water below the level of the liquid can cause the liquid to splash and spread the fire, while directing water in line with or in the center of the liquid may not effectively cool the tank and extinguish the fire. By directing the water above the level of the liquid, it can effectively cool the tank and prevent the fire from spreading.

Polar solvents are flammable and combustible liquids that mix with water. Unlike hydrocarbons, which are nonpolar and do not mix with water, polar solvents have a partial positive and negative charge, allowing them to dissolve in water. This property makes them flammable and combustible, as they can mix with water and easily ignite or burn. Polar solvents are commonly used in various industries, such as cleaning, paint thinning, and chemical synthesis.

Combustible liquids are substances that have flash points higher than 100°F (38°C). This means that they require a higher temperature to ignite compared to flammable liquids. Combustible liquids can still catch fire and burn, but they have a higher threshold for ignition. Gaseous liquids, semi-solid liquids, and flammable liquids do not necessarily have flash points higher than 100°F, so they are not the correct answer in this case.

In fires in vehicles transporting flammable fuels, it can be difficult to identify the specific products involved due to the potential for multiple types of fuels being transported. This is a major difference compared to fires in flammable liquid storage facilities where the products are typically known and can be easily identified.

The major difference between fires in vehicles transporting flammable fuels and in flammable liquid storage facilities is not an increased water supply. Fires in vehicles are often more unstable due to the movement of the vehicle, making it difficult to control the fire and contain spills. Additionally, the risk to passing motorists is higher in vehicle fires as compared to fires in storage facilities where the risk is limited to the facility itself.

Natural gas, in its pure form, consists mainly of methane. Methane is a flammable gas, meaning it can ignite and burn. However, it is considered nontoxic, which means it is not harmful or poisonous to humans or animals. This makes the statement that natural gas, in its pure form, is methane, which is flammable but nontoxic, the most accurate statement.