BC CARPENTER APPRENTICESHIP PROGRAM

Transcription

1 BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 COMPETENCY A-4: Describe Fire Safety Procedures COMPETENCY A-4

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3 Acknowledgements and Copyright Permission Copyright 2015 Industry Training Authority This publication may not be reproduced in any form without permission by the Industry Training Authority. The Industry Training Authority of British Columbia would like to acknowledge the Carpentry Articulation Committee and Open School BC, a division of the BC Ministry of Education, as well as the following individuals and organizations for their contributions in updating the BC Carpenter Apprenticeship Learning Guides: Carpentry Articulation Curriculum Committee members Dennis Carlson, Tom Haag, Erik Hardin, Alf Leimert, Geoff Murray, Don Naidesh, Stephen Pelley, Al van Akker Writers: Gary Backlund, Geoff Murray Reviewers: Roy Mironuck, Geoff Murray, Stephen Pelley Open School BC Christina Teskey, project manager Dennis Evans, production technician, photographer, graphics, art coordination Brian Glover, production technician Shannon Sangster, copyright management Christine Ramkeesoon, art coordination Max Licht, artist Greg Aleknevicus, editor Keith Learmonth, editor Queen s Printer Contact Director, Crown Publications, Queen s Printer at Image Acknowledgments Cover image licensed from Thinkstock. Every effort has been made to secure copyright permission for the images used in this document. These materials contain information that has been derived from information originally made available by the Province of British Columbia at: and this information is being used in accordance with the Queen s Printer License British Columbia available at: ca/standards/2014/qp-license_1.0.html. They have not, however, been produced in affiliation with, or with the endorsement of, the Province of British Columbia and THESE MATERIALS ARE NOT AN OFFICIAL VERSION. ISBN: Please note that it is always the responsibility of any person using these materials to inform him/herself about the Occupational Health and Safety Regulation pertaining to his/her work. The references to WorkSafeBC safety regulations contained within these materials do not / may not reflect the most recent Occupational Health and Safety Regulation (the current Standards and Regulation in BC can be obtained on the following website: We want your feedback! Please go to the BC Trades Modules website ( to enter comments about specific sections that require correction or modification. All submissions will be reviewed and considered for inclusion in the next revision. Ordering Crown Publications, Queen s Printer PO Box 9452 Stn Prov Govt 563 Superior St. 2nd Flr Victoria, B.C. V8W 9V7 Phone: Fax: crownpub@gov.bc.ca Web: Version 1, July 2015

4 COMPETENCY A-4 Describe Fire Safety Procedures Contents Learning Task 1: List the Three Components That Must Be Present Before a Fire Can Occur Self Test Learning Task 2: Identify Class A, B, C, and D Fires and State the Type of Extinguisher Used to Put Out Each Self Test Learning Task 3: Describe the Use of Fire Extinguishers Self Test Learning Task 4: Describe Flashpoint and Autoignition Temperatures for Flammable Liquids...27 Self Test Learning Task 5: State Fire Safety Precautions Self Test Learning Task 6: Describe the Safe Installation of Temporary Heating Self Test Answer Key BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1

5 COMPETENCY A-4 Describe Fire Safety Procedures Fundamental knowledge of the causes of fires and fire prevention will help reduce the number of construction-related fires that occur each year in Canada. Knowing the types of fires and how to fight them can save buildings and workers. Objectives When you have completed the Learning Tasks in this Competency, you should be able to: understand the science of fire identify Class A, B, C, and D fires and state the type(s) of fire extinguisher that should be used to put out each type describe how to extinguish Class A, B, C, and D fires using a fire extinguisher describe flashpoint and autoignition state the fire safety precautions to be observed while working near, handling, or storing flammable liquids or gases, oily rags, paper or wood products, and electrical apparatus describe safety considerations for using temporary construction heaters Competencies Written: Describe fire safety procedures You will be tested on your knowledge of types of fires, procedures for extinguishing fires, and methods of preventing fires. BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 5

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7 Learning Task 1 Competency A-4 LEARNING TASK 1 List the Three Components That Must Be Present Before a Fire Can Occur Fire or combustion is a form of oxidization (the reaction of a substance with oxygen). During the process of oxidization, energy is released in the form of heat, sometimes accompanied by light. Oxidization takes place at varying rates of speed. Here are some examples of oxidization occurring at differing rates of speed: very slow rusting iron slow spontaneous heating of materials such as oil-soaked rags fast burning paper or wood extremely fast exploding gunpowder upon ignition HEAT OXYGEN (air) FUEL Figure 1 Fire triangle The Fire Triangle (Figure 1) illustrates the three necessary components required to support combustion: air oxygen, usually in the form of air, to sustain combustion fuel a combustible material such as wood, gasoline, paper, cloth, fumes, and gases heat heat sufficient to raise the fuel to its ignition temperature The level of heat needed for combustion of liquid vapours is known as the flashpoint (the lowest temperature needed for ignition). Liquids with flashpoints lower than 37.8 C are classed as flammable. Liquids with higher flashpoints are classed as combustibles. Paint thinner has a flashpoint of about 40 C, making it relatively fire-safe at normal working temperatures. More information on flashpoint is given in Learning Task 4 of this Competency. BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 7

8 Learning Task 1 Competency A-4 Autoignition (kindling point) is the lowest temperature at which a substance will spontaneously ignite without an external ignition source such as a flame or spark. Flashpoint should not be confused with the autoignition temperature. For example, the flashpoint of gasoline is 45 C but its autoignition temperature is 280 C. Paper is not a liquid, so the term flashpoint does not apply, but it will autoignite at about 233 C. A pile of oil-soaked rags will create heat due to the oxidation process. On a warm day, enough heat can be generated to reach the oil s autoignition temperature, causing spontaneous combustion. Many partially constructed buildings have been lost due to this form of oxidation. Keeping fuel, heat, and oxygen separated prevents a fire from occurring. Likewise, an existing fire can be extinguished by removing any one of the three components. Remove any one of the three components of the fire triangle and the fire cannot continue. Here are some examples of how this can be accomplished: remove the fuel from the vicinity of the fire (e.g., shut off valve of gas main) and the result is starvation remove the heat (e.g., apply water) and the result is cooling remove the oxygen (e.g., cover the fire with a lid, a wet blanket, some sand, or use carbon dioxide, foam, or a dry chemical) and the result is smothering Now complete Self Test 1 and check your answers 8 BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1

9 Learning Task 1 Competency A-4 Self Test 1 1. Before a fire can occur, three components must be present. Name those components. 2. What will happen to a fire if one of the components represented in the Fire Triangle is removed? 3. Explain what a flashpoint is. 4. Explain what autoignition is. 5. What causes oily rags to ignite? BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 9

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11 Learning Task 2 Competency A-4 LEARNING TASK 2 Identify Class A, B, C, and D Fires and State the Type of Extinguisher Used to Put Out Each Fires have been divided into four main classes: A, B, C, and D. The classification of a fire dictates the type of extinguisher required. Every approved fire extinguisher has one or more symbols marked on it to indicate what type of fire it s designed to be used on. For some fires, it s dangerous to use the wrong type. When a fire is spotted, you must first identify the fire type and choose the extinguisher with the corresponding symbol. If the fire is too large, do not attempt to extinguish it yourself. Evacuate the area and call 911 immediately. Always maintain a path to safety anytime you attempt to suppress a fire. Classes of Fires There are many types of fires and each has its own requirements for extinguishing. For firefighting purposes, all fires have been broken down into four general groups or classes. Class A Class A fires involve ordinary combustible materials such as wood, cloth, paper, rubber, and many plastics. For this type of fire, the heat-absorbing (cooling) effects of chemicals that retard combustion are required. Use an extinguisher with the A symbol on it. OR BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 11

12 Learning Task 2 Competency A-4 Class B Class B fires involve flammable liquids. An extinguisher that smothers the liquid (removes oxygen) without spreading it is required. Do not use water, as it will spread the flaming liquid around and increase the area of the fire. Use an extinguisher with the B symbol on it. OR Class C Class C fires involve energized electrical equipment. Do not use water, as it can conduct electricity. A non-conductive agent is required to extinguish this type of fire. If safe to do so, de-energize the electrical equipment. Use an extinguisher with the C symbol on it. If it can be confirmed that the equipment has been de-energized, a Class A or B extinguisher may be used to fight a Class C fire. OR Class D Class D fires involve certain combustible metals such as magnesium, titanium, zirconium, sodium, and potassium. A heat-absorbing medium that smothers the fire is needed. Do not use water, as it reacts with magnesium and will cause an explosion. Use an extinguisher with the D symbol on it. 12 BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1

13 Learning Task 2 Competency A-4 Types of Extinguishers Although some shops still provide pails of sand for smothering small Class B or D fires, most carry modern portable fire extinguishers. These come in many sizes and colours and have several markings. However, extinguishers can generally be divided into four types: water extinguishers dry chemical extinguishers dry powder extinguishers CO 2 extinguishers Most portable extinguishers can be used on more than one class of fire, but none is effective on all types. It s important to know the location of each extinguisher in your workplace and the procedure for operating it. Because each manufacturer uses a slightly different operating procedure, look carefully at the markings and read the instructions on the extinguisher. The instructions explain where and how the extinguisher is most effectively used. Class A Fire Water-based extinguishers are made for Class A fires (wood, paper, textiles, etc.). They may be pressurized (Figure 1) or gravity-fed, or they may incorporate a pump. Locking pin Operating or discharge lever Gauge Discharge gas Water level Nozzle Discharge tube Strainer Figure 1 Pressurized water extinguisher for burning wood, paper, textiles, and other types of Class A fires BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 13

14 Learning Task 2 Competency A-4 Water-based extinguishers should not be used on electrical fires because of the danger of electrical current travelling up the water stream, which will result in an electric shock. Additionally, a water-based extinguisher should not be used on burning liquids. Not only is water ineffectual in putting out this kind of fire, but it also spreads the flames over a wider area. Protect a Class A extinguisher from freezing temperatures. Class B and C Fires Dry chemical extinguishers (Figure 2) are designed for Class B and C fires (oil, paints, petroleum-based substances, electrical equipment). They can also be used for Class A fires depending on the type of agent in the cylinder. Three commonly used dry chemicals are: Triplex A B C Quick-aid Purple K Triplex A B C This multi-purpose dry chemical agent is effective in extinguishing Class A, B, and C fires. It s generally considered the best all-round fire extinguisher. Quick-aid This specially treated sodium bicarbonate dry chemical agent is moistureresistant and free-flowing. It s approved for Class B and C fires and offers the lowest cost per kilogram of the three dry chemical agents. Purple K This specially treated potassium bicarbonate dry chemical agent provides protection against Class B and C fires. It s about twice as effective as the standard sodium bicarbonate dry chemical. 14 BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1

15 Learning Task 2 Competency A-4 Locking pin and seal Operating or discharge lever Carbon dioxide gas Siphon tube Discharge horn Carbon dioxide (CO2) Liquid carbon dioxide Pressure gauge Operating or discharge lever Discharge gas Discharge tube Dry chemical Nozzle Dry chemical Figure 2 Extinguishers for Class B and C fires: dry chemical and carbon dioxide Carbon Dioxide A carbon dioxide (CO 2 ) extinguisher, which is recognizable by its fibre discharge horn, is designated only for Class B and C fires. It s less effective than a dry chemical extinguisher but it has the advantage of not leaving a residue. Class D Fires Class D extinguishers use a special extinguishing dry powder agent, sand, or chips to smother Class D fires (combustible metals such as magnesium, titanium, zirconium, sodium, or potassium). This powder can be made of dry graphite, dry cast iron turnings, other approved compounds with a graphite base, or a dry substance with a chloride base. BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 15

16 Learning Task 2 Competency A-4 Figure 3 Extinguishing powder applied by shovel or scoop Under no circumstances should water or any standard fire extinguisher (of the pressurized or liquid type) be used to combat a magnesium fire. To extinguish a magnesium fire, cover the burning chips with an approved extinguishing powder. This material forms an air-excluding crust over the burning metal. The extinguishing powder is commercially available and contains other ingredients that prevent water absorption and ensures free-flowing characteristics. When trying to suppress a Class D fire in its initial stage, localize the fire by scraping away any adjacent metal chips. The smothering material should then be applied gently to avoid scattering the fire. Welding Blanket Workers are occasionally required to weld or use a cutting torch above or close to a flammable substance. In these situations, a WorkSafeBC-approved flame-retardant blanket should be used to catch sparks and slag. The blankets are about m in size. Emergency Fire Blanket Emergency fire blankets weigh less than welding blankets and are designed to smother the flames if someone s clothing catches fire. The blankets are about 2 2 m in size. 16 BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1

17 Learning Task 2 Competency A-4 Fire Extinguisher Sizes and Ratings The size of a fire extinguisher is often based on the weight of the extinguishing agent. Small extinguishers may be labelled as 2.5 lb. and large ones as 10 lb. or more. The size of fire it s effective against may also be rated in the case of a multi-class extinguisher. For example, an extinguisher may be labelled as Class ABC 5 lbs, 3A:10B:C. In rough terms, it s effective against a 3 cubic ft. Class A fire, or a 10 cubic ft. Class B fire. The C does not have a number assigned. Fire Extinguisher Maintenance Fire extinguishers are date-labelled. They come packaged with a maintenance log tag. The tag is attached to the extinguisher to act as a maintenance record (Figure 4). Figure 4 Inspection log form The extinguisher requires servicing if it s been used or if the gauge shows that it isn t fully charged (Figure 5). Figure 5 Pressure gauge Fire extinguishers need to be inspected annually. Most require the dumping and recharging of the extinguishing agents every six years. Pressurized extinguishers also need hydrostatic testing every 12 years. BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 17

18 Learning Task 2 Competency A-4 Over time, the dry chemical powder can get packed at the bottom of the tank, making the extinguisher ineffective for fire suppression. This is especially a problem with extinguishers mounted on vehicles. Once per year, the extinguisher should be inverted and the bottom tapped with a rubber hammer to loosen the chemical powder. Storage Extinguishers need to be located near exits. When moving towards an extinguisher, you should be travelling away from harm (toward an exit) rather than into the fire area. The location of the extinguisher should be well marked with a large sign (Figure 6). Carpenters should also have an extinguisher mounted near a door of their work vehicle. Figure 6 Extinguisher signage Now complete Self Test 2 and check your answers 18 BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1

19 Learning Task 2 Competency A-4 Self Test 2 1. List the classes of fires and, for each class, give an example of the type of material that will burn. 2. State the most effective method of extinguishing each of the following types of fires: a. gasoline b. wood c. electrical equipment 3. List the classes of fires that may be extinguished with the following types of extinguishers: a. carbon dioxide (CO 2 ) b. dry chemical c. water BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 19

20 Learning Task 2 Competency A-4 4. Why is water not used on the following types of fire? a. Class C fires b. Class B fires 5. Draw the symbols that are used to identify Class A, B, C, and D fire extinguishers and label each. 6. What all-round fire extinguisher is currently the best? 7. How often should a fire extinguisher be inspected? 20 BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1

21 Learning Task 3 Competency A-4 LEARNING TASK 3 Describe the Use of Fire Extinguishers Although this Learning Task describes the use of fire extinguishers, remember that the most important step when dealing with a fire is ensuring that a personal method of egress (way of exiting the building) is available. Warning Others and Fire Department Fire prevention is always preferred over firefighting but 100% prevention is not always possible. Fighting a fire calls for quick and careful decision-making. Fires are very dangerous, and you must not endanger yourself or others when attempting to extinguish one. On first discovering a fire, activate the fire alarm system to alert other workers to exit the building. Follow the fire emergency response plan at your workplace, which may require immediately calling the local fire department by dialing 911. Evacuation of Others Assist any person in immediate danger to the safest exit if it can be accomplished without risk to yourself or others. If they re in distress, stay with the person until the fire department arrives. Choosing Not to Fight a Fire Although many fires are small and can be dealt with safely, it s important to recognize the situations where it s best to not fight a fire: A fire extinguisher is useful only in the beginning stages of a fire. If the fire is already spreading quickly, it s best to simply evacuate the area, closing doors behind you as you leave. If you don t have the correct type or large enough extinguisher. If you re uncomfortable with the situation for any reason. In these situations, allow trained firefighters to deal with the fire. Personal Method of Egress If you do choose to extinguish a fire, the most important rule is to position yourself with an exit or means of escape. If the extinguisher malfunctions or the fire gets beyond your control, you need to exit quickly. Always keep an exit at your back. BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 21

22 Learning Task 3 Competency A-4 Fire Contained and Not Spreading Before attempting to extinguish a fire, check for electrical hazards, explosive hazards, and toxic fumes. Beware of materials that produce toxic gas when they burn. Know which materials produce these gases and how to protect yourself. If any of these hazards are present, do not attempt to extinguish the fire. In the case of explosive hazards or toxic fumes, evacuate the area and allow trained fire personnel to put out the fire. If the fire is small, contained to a specific area, and not spreading, use an extinguisher to put out the fire. Determine the class of fire and use the appropriate fire extinguisher. Remember that using the wrong type of extinguisher can cause the fire to spread or increase in intensity. Training All workers required to use fire extinguishers should receive training that covers: extinguisher locations classes of fire most likely to break out and the appropriate extinguisher to use when and how to use extinguishers importance of sounding the alarm health and safety hazards personal protective equipment Employers are encouraged to use lectures and demonstrations, and give workers plenty of opportunity to practise using extinguishers (practising with extinguishers needing recharging is recommended). Operating instructions must be posted at each extinguisher, and all workers must understand them. Retraining should be provided as needed. Using a Fire Extinguisher Your first response when choosing to fight a fire is to use whatever is at hand to extinguish it before it expands. It s important to know the location and operation of each extinguisher in your workplace. Since each manufacturer uses a slightly different operating procedure, read the markings and instructions on the extinguisher carefully they will tell you how to use the extinguisher and where it s most effective. Although most of these fire extinguishers can be used on more than one class of fire, none can handle all types. 22 BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1

23 Learning Task 3 Competency A-4 Extinguisher Selection All shops and construction sites must have portable fire extinguishers. These come in many sizes and colours and have several markings on them. See Learning Task 2 in this Competency for information regarding types and sizes. It s essential to use the correct fire extinguisher for the type of fire being fought. Pull, Aim, Squeeze, Sweep The proper use of a portable fire extinguisher can be remembered with the acronym PASS, which stands for Pull, Aim, Squeeze, and Sweep. Stand 1.8 to 2.4 m (6 8') from the fire and pull, aim, squeeze, and sweep the fire off the fuel. Pull Pull the pin out of the handle using the ring attached to it. The pin prevents the extinguisher from being accidentally discharged. As long as the pin is in place, you can t squeeze the handle to discharge the extinguisher. The pin may be secured with an easily broken plastic strap. Aim Aim the extinguisher nozzle at the base of the flames to remove the oxygen first that s where the burning material is located. If you aim at the flames, the extinguishing agent will pass over the fire without effect. Squeeze Squeeze the handle this will release the pressurized extinguishing agent. Sweep 1. Start with the portion of the fire closest to you and sweep the extinguisher from side to side. 2. Cover the fire with the extinguishing agent and continue to sweep the fire further and further away from you. The idea is to sweep the fire completely off the fuel. 3. Be careful not to enter the fuel area where the fire could get behind you. 4. Keep spraying until the fire is out, and make sure it doesn t re-ignite. BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 23

24 Learning Task 3 Competency A-4 Don t worry about saving extinguishing agent for a later fire. Once an extinguisher has been even partially discharged, it must be recharged before being returned to service. A good practice is to lay fully discharged extinguishers on their side, rather than setting them upright standing on their base. Setting an extinguisher on its side indicates it is fully discharged other people won t waste time trying to use it if more extinguishing agent is required. To operate an extinguisher: Pull Aim Squeeze Sweep 1 PULL the pin 2 AIM nozzle at base of fire 3 SQUEEZE the handle 4 SWEEP Know your extinguisher nozzle side to side Use the correct extinguisher Check your own extinguisher s label for detailed instructions Figure 1 PASS Operating a Pressurized Water Extinguisher Remove the locking pin and squeeze the operating or discharge lever. The extinguisher is pressurized with air or inert gas through a hose line. Charging pressures vary from 360 to1050 kpa (about psi). Many gauges are still in imperial measurement. Direct the stream at the base of the fire, then follow the flame while working from side to side until the fire is extinguished. Control the discharge by using the discharge valve. Operating a Pump-type Water Extinguisher The method for a pump-type water extinguisher is the same as for a pressurized one, except that you have to pump as you spray. In some cases, the nozzle will be adjustable to provide a stream or a spray. This type of extinguisher can be refilled on, site for further use. 24 BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1

25 Learning Task 3 Competency A-4 Operating a Dry Chemical Extinguisher Remove the locking pin, aim the nozzle at the base of the fire, and then squeeze the operating or discharge lever. Direct the stream at the base of the fire, then follow the flame while working from side to side until the fire is extinguished. Control the discharge by using the discharge valve. Operating a CO 2 Extinguisher A CO 2 extinguisher works similarly to a dry chemical extinguisher, except instead of smothering the fuel source with a powder, it uses gas to smother the fire by replacing the oxygen with CO 2. To minimize the possibility of re-flash, continue the application even after the fire has gone out. The effectiveness of a CO 2 extinguisher is reduced under windy conditions, because CO 2 is a gas and dissipates easily. Be aware that when using a CO 2 extinguisher in a confined area, the atmosphere may become oxygen-deficient. Do not touch the discharge horn, as it becomes very cold during use. Before Starting a Job Before starting a job that involves a fire risk, know what types of fire extinguishers are available and where they re placed. Now complete Self Test 3 and check your answers BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 25

26 Learning Task 3 Competency A-4 Self Test 3 1. What is the first step when discovering a fire? 2. Where should you be located when fighting a fire? 3. What does PASS stand for? 4. What are two safety concerns when using a carbon dioxide (CO 2 ) extinguisher? 5. If the fire is too big to fight, what should you do when evacuating a building? 26 BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1

27 Learning Task 4 Competency A-4 LEARNING TASK 4 Describe Flashpoint and Autoignition Temperatures for Flammable Liquids Most liquid solvents are flammable and many are explosive. Extinguish solvents with a Class B extinguisher. Part 4 of the material safety data sheet (MSDS) for each product lists the fire and explosion data along with the flashpoint and method for firefighting. All flammable liquids are volatile by nature, but it s the liquid s vapours (combined with air), rather than the liquid itself, that ignites and burns. The rate of evaporation varies from one liquid to another and increases with temperature. Increased temperature also increases vapour production this creates a more hazardous condition. The degree of hazard depends on the following: flashpoint concentration of the air-vapour mixture proximity of an ignition source Flashpoint and Autoignition Temperature The level of heat needed for combustion of liquid vapours is known as the flashpoint (the lowest temperature needed for ignition). Liquids with flashpoints lower than 37.8 C are classed as flammable. Liquids with higher flashpoints are classed as combustible. Autoignition (kindling point) is the lowest temperature at which a substance will spontaneously ignite without an external ignition source such as a flame or spark. Gasoline is a hydrocarbon with a flashpoint of 45 C and an autoignition temperature of 280 C. Acetone is a highly volatile solvent, and is used by carpenters to clean up excess adhesive during laminate work. Its flashpoint is 20 C and its autoignition temperature is 465 C. Polyurethane varnish has a flashpoint of approximately 39 C and paint thinner has a flashpoint of about 40 C, making both liquids relatively fire-safe at normal working temperatures. BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 27

28 Learning Task 4 Competency A-4 Sources of Ignition Industrial sources of ignition exist in a variety of places. Common sources include: hot furnaces sparks from friction and tools operations using electrical equipment discharges of static electricity autoignition of some substances, such as very fine dust open flames, such as plumber s torches Water-based Products In recent years, many of the flammable liquids used by carpenters have been replaced with water-based products. In general, water-based products are not flammable and are safer than solvent-based products. Now complete Self Test 4 and check your answers 28 BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1

29 Learning Task 4 Competency A-4 Self Test 4 1. To put out burning solvents, which type of fire extinguisher is used? a. Class A b. Class B c. Class C d. Class D 2. When a flammable liquid burns, it s the that burns. a. liquid itself b. vapours from the liquid c. flashpoint d. ignition source 3. The flashpoint of a liquid is the: a. lowest temperature at which its vapours will ignite b. highest temperature at which its vapours will ignite c. increase in the rate that vapours are produced d. decrease in the rate that vapours are produced 4. Which of the following is not considered a source of ignition? a. hot furnaces b. discharge of static electricity c. hot steam d. open flame 5. Which Part of the MSDS sheet covers flammability and firefighting? a. Part 1 b. Part 2 c. Part 3 d. Part 4 BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 29

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31 Learning Task 5 Competency A-4 LEARNING TASK 5 State Fire Safety Precautions Fire is possible only where there is a supply of combustible materials, oxygen, and heat. Risky behaviour, equipment failure, or human error can cause ignition. Handling and Storage of Flammable Materials The nature of flammable materials makes them vulnerable to ignition. Consequently, the following storage precautions are necessary: All containers of flammable liquids must be of an approved type and clearly marked. All containers must have secure capping devices. Open flames or lit cigarettes are prohibited within or near any liquid or gas storage area. Where drums are used as containers, they must have taps and a drip tray. Containers must be sealed during transportation. Empty containers must be stored on end. Spills must be cleaned up or covered with sand. Storage cabinets must be of a type approved by the Fire Code. Typically this is a UL or ULC non-combustible cabinet with latching doors. The cabinet must be properly labelled and provide spill containment (Figure 1). Storage cabinets must not be located near exits. Distances to property lines are required for outdoor storage. When storing large quantities, a storage permit may be required. The local fire department should be notified when large quantities of volatile material are stored either temporarily or permanently on a site. WorkSafeBC OHS Regulation Article 5.33 deals with permitted quantities as per the following: 5.33 Permitted Quantities Except for the quantity reasonably needed for immediate use, or that is present for display or sale in public areas of a mercantile facility, the quantity of combustible and flammable liquids stored outside an approved storage cabinet, storage room or storage area in any fire compartment (2 hour fire separation) of a building must not exceed: BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 31

32 Learning Task 5 Competency A-4 a. in closed containers, 600 litres (132 imp gal) of liquids having a flashpoint below 93.3 C (200 F) of which not more than 100 litres (22 imp gal) may be liquids having a flashpoint below 22.8 C (73 F) and a boiling point below 37.8 C (100 F), and b. in storage tanks or portable tanks, 5000 litres (1100 imp gal) of liquids having a flashpoint below 93.3 C (200 F) and a boiling point at or above 37.8 C (100 F). BC Fire Code, Section 4.2 also sets requirements based on the building s use. It classifies flammables as Class 1 or 2. Class 1 has a flashpoint of 37.8 C or lower and Class 2 includes flammables with a flashpoint higher than 37.8 C. For residential structures, a maximum of 30 litres of Class 1 liquids, or 150 litres of Class 2 liquids are permitted, unless the material is stored in an approved cabinet. Figure 1 Flammable material storage cabinet Fuelling Equipment Any equipment that requires a flammable liquid (such as a portable generator) needs to have the same basic precautionary measures as stored liquids: Drivers and operators must be warned of ignition hazards while refuelling such equipment. They must not smoke and the engines must be stopped. Fuelling must be done in a well-ventilated environment, preferably outdoors. 32 BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1

33 Learning Task 5 Competency A-4 All leaks from a tank or other equipment must be reported and repairs made immediately. Spills must be cleaned or covered with sand. Electrical Wiring and Equipment Ensure all wiring, whether permanent or temporary, is safe so that it will not cause fires. The following precautions are necessary: Bury or cover with ramps, any temporary or permanent wiring at ground level to protect it from pedestrian or vehicular damage. Connect all portable, electric-powered hand tools with flexible rubber (cab tire), extension cords, or sheathed PVC cables. Ground portable electric hand tools or have double-insulated protection. Install breakers of appropriate amperage to protect against excess current. Install breakers of the ground fault circuit interrupter (GFCI) type where tools are used outdoors. Combustible Materials Accidental ignition of accumulated rubbish causes many fires. Avoid this hazard with good waste management. Any build-up of packing materials, sawdust, wood shavings, oil waste, or other combustible material constitutes a potential fire hazard. Always take the following precautions: Contain all waste liquids that are flammable in sealed units for disposal off site. Open fires require a permit. Constantly supervise all open fires and extinguish them at the end of the day. Keep fire extinguishers nearby when burning rubbish. Put all oily rags in metal bins containing water and sealed with lids. BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 33

34 Learning Task 5 Competency A-4 Fine Dust Although not a flammable liquid, very fine sawdust is highly flammable and often explosive. Many workers have been killed and many buildings lost due to fine sawdust being ignited by a spark. Practise good housekeeping and ventilate enclosed locations to reduce the likelihood of sawdust fires/explosions. Now complete Self Test 5 and check your answers 34 BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1

35 Learning Task 5 Competency A-4 Self Test 5 1. How must empty containers of flammable materials be stored? 2. How is temporary or permanent wiring at ground level protected from pedestrian or vehicular traffic? 3. How are oily rags stored? 4. Can storage cabinets for flammable materials be located near an exit? BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 35

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37 Learning Task 6 Competency A-4 LEARNING TASK 6 Describe the Safe Installation of Temporary Heating Temporary heating is required on the job site for various reasons: In very cold weather during the construction phase, from excavation until backfill, heating is used to keep the soil from freezing. In cold weather, heating is used to keep fresh concrete warm enough to cure. In almost all weather conditions, heating is used to dry the tape and mudding compound for drywall. Heating may also be used to improve the comfort of workers. Temporary job site heating may be powered by electricity or fuelled by propane, kerosene, or diesel. These heaters are usually non-ducted and are therefore considered space heaters they re most commonly known as construction heaters. Construction heaters are rated by the amount of heat they produce in one hour, either in kilowatts or British thermal units BTU/hr. = 29.3 kw. Combustion-type Heaters Heaters that burn a fuel are known as combustion heaters. Propane is bottled as a liquid and burned in a gaseous form. Kerosene and diesel are liquid fuels that are burned as vapours. These fuels can be explosive if used incorrectly. They can also cause carbon monoxide poisoning or oxygen-deficient atmospheres. Combustion-type heaters generally operate at higher temperatures than electrically-powered construction heaters, and extra precautions should be taken against burns and fire: Follow the manufacturer s instructions. Allow heaters to cool before refuelling. Check for leaks and repair any immediately. Use on a non-combustible base as per the manufacturer s instructions. Some heaters are required to be operated on a minimum 2.5 cm (1") thick concrete slab. BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 37

38 Learning Task 6 Competency A-4 Do not use within 3 m (10') of any pile of debris, tarps, or combustible or flammable material. Any nearby tarps must be securely tied down. A Class A and Class B fire extinguisher must be nearby. Oxygen is consumed by combustion make sure there is a fresh air supply. Do not allow heaters to be operated if unattended. Do not paint, spray, or work with flammable liquids while the heater is operating. Propane Propane heaters are fuelled by bottled propane often referred to as propane cylinders. The following precautions apply to propane cylinders: Turn the gas valve off at the cylinder when not in use. Keep the cylinder at least 1.8 m (6') away from the heater and do not point the heater in the direction of the cylinder. Do not store extra cylinders inside. Never manifold together more than three 100 lb. cylinders. Propane cylinders must be secured against tipping. Never use or store below grade level. Propane is heavier than air and will pool in low spots. Figure BTU/hr propane construction heater 38 BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1

39 Learning Task 6 Competency A-4 Kerosene and Diesel Oil Kerosene and diesel oil fuels burn hotter than propane and produce a much greater amount of carbon monoxide. The following precautions must be taken with these types of heaters: A fuel shut-off must be supplied in the same room as the heater if supplied by a bulk tank. Test heated areas for carbon monoxide and install a carbon monoxide alarm. The fuel-air mixture must be checked by a trained worker. The colour and shape of flame should be checked often. Vent heater exhaust outdoors when possible. The CSA B139 Code for installing oil-fired construction heaters lists the following requirements: 1. The person activating the heater must be competent in the installation and operation of construction heater equipment. 2. Before leaving the installation of the construction heater, the person who activated the heater must: a. Ensure that the installed construction heater, accessories, components, and all equipment comply with the Code, and that the oil-fired construction heater is ready for safe use. b. Instruct the user in the safe and correct operation of the construction heater and accessories. c. Ensure that the manufacturer s instructions supplied with the construction heater are provided to the user. 3. Manufacturer instructions for the care and operation of the oil-fired appliance must be located in a noticeable place near the construction heater. Electric Heaters Portable electric space heaters can create shock, fire, and burn hazards if used or installed incorrectly. Construction heaters rated at 3000 watts or more require extra caution, as the high output creates considerable heat. Take the following precautions when using an electric heater: Use only CSA- or ULC-approved heaters. Follow the manufacturer s instructions. Do not hang from ceilings or rafters unless approved by the manufacturer for that type of installation. BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 39

40 Learning Task 6 Competency A-4 Do not remove the plug and hardwire direct to a power supply. Do not use where there is limited airflow or block the air intake, as this can cause overheating. Do not use the heater to dry jackets, raingear, or boots. Do not use with an extension cord. Use a circuit with a properly-sized breaker. Plugging into a range or dryer circuit may not give proper protection. Protect with a ground fault circuit interrupter (GFCI) if used in damp locations. Keep away from combustible surfaces and materials. Place heaters on only non-combustible surfaces that extend a minimum of 1.5 m (5') beyond the front of the heater. Do not operate near flammable materials or volatile fumes. Figure watt (4.8 kw) electric construction heater Maintenance and Storage Make sure the heater is cool before putting it away. Check for rust, loose or bent parts, and mechanical damage. Look for build-up of dust, drywall compound, or other substances and clean if needed. Make sure the cord and plug are in good condition. Do not leave a construction heater operating if unattended. Now complete Self Test 6 and check your answers 40 BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1

41 Learning Task 6 Competency A-4 Self Test 6 1. Name three fuel types used for construction heaters. 2. A 4000 watt heater would be equivalent to how many BTU/hr.? 3. How many 100 lb. propane bottles can be safely connected together? 4. What should be located near a combustion-type construction heater? 5. What hazards exist if electric construction heaters are used or installed incorrectly? 6. Is it safe to leave a construction heater operating overnight if unattended? BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 41

42 Answer Key Competency A-4 Answer Key Self Test 1 1. Fuel, heat, and oxygen 2. The fire will be extinguished. 3. The lowest temperature at which the vapour from a liquid will ignite. 4. The lowest temperature at which a substance will spontaneously ignite without an external ignition source. 5. Heat caused by oxidation igniting the oil. Self Test 2 1. Class A wood, paper, cloth Class B gasoline, oil, grease Class C electric motor, television Class D magnesium, titanium, sodium 2. a. Gasoline fire is best extinguished by removing the oxygen or smothering. Use a carbon dioxide or dry chemical extinguisher. b. Wood fire is best extinguished by cooling or removing the fuel source. Use a water extinguisher. c. Electrical equipment fire is best extinguished by starvation. If possible, de-energize the equipment, and use a dry chemical or carbon dioxide extinguisher 3. a. Class B or C b. Class A, B, or C c. Class A 4. a. Water should not be used on Class B fires because of the potential of spreading the fire. 5. b. Water should not be used on Class C fires because of the possibility of electric shock. OR OR OR 6. Triplex A B C 7. Annually 42 BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1

43 Answer Key Competency A-4 Self Test 3 1. activate the fire alarm system m (6 8') from the fire with an exit at your back 3. Pull, Aim, Squeeze, and Sweep 4. oxygen-deficient air, touching the discharge horn 5. close the doors behind you Self Test 4 1. b. Class B 2. b. vapours from the liquid 3. a. lowest temperature at which its vapours will ignite 4. c. hot steam 5. d. Part 4 Self Test 5 1. Empty containers must be stored on end. 2. By burying or protecting with ramps 3. In metal bins containing water and sealed with lids 4. No Self Test 6 1. propane, diesel oil, kerosene BTU 3. three 4. a Class A and Class B fire extinguisher 5. shock, fire, and burn hazards 6. no BC CARPENTER APPRENTICESHIP PROGRAM LEVEL 1 43

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