Flammable and Combustible Liquids The determining factor in whether a liquid is flammable or combustible is its flashpoint. Flashpoint: The minimum temperature at which a liquid gives off enough vapor within a test vessel in sufficient concentration to form an ignitable mixture with air near the surface of the liquid. Remember, it is the vapors, not the liquid, that Burns! A chemical’s flashpoint is listed on the MSDS under the Fire and Explosion section.
Flammable Liquids Any liquid having a flashpoint below 100o F (37.8o C) or lower. NFPA Classes IA, IB, & IC Combustible Liquids Any liquid having a flashpoint at or above 100o F (37.8o C). NFPA Classes II & IIIA & B Flammable and Combustible Liquids
Flammable and Combustible Liquid Classifications Flammable Liquid - any liquid having a flashpointbelow 100o F (37.8o C) or higher, the total of which make up 99 percent or more of the total volume of the mixture. Flammable liquids shall be known as Class I liquids. Class I liquids are divided into three classes as follows: Class IA - shall include liquids having flashpoints below 73 F (22.8 C) and having a boiling point below 100 F (37.8 C). Class IB - shall include liquids having flashpoints below 73 F (22.8 C) And having a boiling point at or above 100 F (37.8 C). Class IC - shall include liquids having flashpoints at or above 73 F (22.8 C) and below 100 F (37.8 C).
Flammable and Combustible Liquid Classifications (Cont.) Combustible Liquid- any liquid having a flashpoint at or above 100o F (37.8o C). Combustible liquids shall be divided into two classes as follows: Class II - shall include those with flashpoints at or above 100 F (37.8 C) and below 140 F (60 C), except any mixture having components with flashpoints of 200 F (93.3 C) or higher, the volume of which makes up 99 percent or more of the total volume of the mixture. Class III - shall include those with flashpoints at or above 140 F (60 C).
Flammable and Combustible Liquids Classifications (Cont.) Class III liquids are subdivided into two subclasses: Class IIIA - shall include those with flashpoints at or above 140 F (60 C) and below 200 F (93.3 C), except any mixture having components with flashpoints of 200 F (93.3 C), or higher, the total volume of which makes up 99 percent or more of the total volume of the mixture. Class IIIB - shall include those with flashpoints at or above 200 F (93.3 C).
200 IIIA COMBUSTIBLE (Flash Point >100 F) 140 II 100 IC 73 FLAMMABLE (Flash Point < 100 F) IA IB 100 Boiling Point (F) Classes of Flammable and Combustible Liquids Flashpoint(Fo)
Triethalemine 17o F Barsol A-2316 54o F Acetone Solvent 0o F Barsol A-2343 56o F Barsol A-3447 0oF N-Butanol 36o F Sec. Butanol 72o F Glycol Ether 94o F Enamel Reducer 20o F Isopropyl Alcohol 45oF Methanol 45o F MEK 23o F Xylene 79o F Toluene 45o F Gasoline -50o F 142 Solvent 66/3 610 F Flammable Liquids in the Plant
Explosive Limits Explosive limits involve the concentration level of the given chemical in the air. In popular jargon, a vapor/air mixture below the flammable limit is too lean to burn or explode. A mixture above the upper flammable limits is too rich to burn. Most flammable liquids are volatile, meaning they evaporate quickly, and can reach a concentration in air that could lead to an explosion.
Controlling the potential for fire and explosion with flammable liquids is done through safe Storage, Transfer, Use and Disposal!
Hazards of Flammable Liquids Exposure Control Measures Include: • Eliminating flames, static electricity, & sparks from electrical circuits. • Temperature. • Proper Ventilation. • Grounding/Bonding. • Spill Control/Emergency Response. • Proper disposal of spent flammable liquids and soaked rags.
Flammable and Combustible Liquids Definitions Grounding: Applying a grounding wire to a container to eliminate a difference in static charge changes the potential between an object and ground. Bonding: Use of a wire between two drums to eliminate the static charge potential between objects.
Flammable and Combustible Liquids Definitions (cont.) Ventilation: Adequate if it is sufficient to prevent the accumulation of significant quantities of vapor-air mixtures in concentrations over ¼ of the Lower Explosive Limit. Safety Can: An approved red container, of not more than 5 gallons capacity, having a spring-closing lid and spout cover and so designed that it will safely relieve internal pressure when subjected to fire exposure. Oily Waste Can: A self closing metal container used to store oil soaked rags.
FLAMMABLE Keep Fire Away Container & Portable Tank Storage Design, Construction and Capacity of Containers Only approved containers and portable tanks may be used to store flammable and combustible liquids. Metal containers and portable tanks meeting the requirements of the Department of Transportation are deemed acceptable when containing products. Not more than 60 gallons of Class I and/or Class II liquids, or not more than 120 gallons of Class III liquids may be stored in an individual cabinet.
Safe Storage Practices • No open flames, smoking, sparks or welding is allowed in flammable liquid storage areas. • Store in a cool location. Not outside in direct sunlight. The warmer the flammable liquid is the more vapors it generates! • Storage shall be in an open or well ventilated area. • Do not store need oxidizers. • Drums of flammable liquid shall be grounded. • A 10 lbs. fire extinguisher shall be readily accessible within the storage area.
Storage Inside Building • Flammable or combustible liquid drums shall not be stored so as to limit use of exits, stairways, or areas normally used for the safe egress of people. • The storage of flammable or combustible liquids in containers or portable tanks is prohibited in office occupancy areas, except that which is required for maintenance and operation of building and operation of equipment. • Leaking containers shall be removed to a storage room or taken to a safe location outside and the contents transferred to an undamaged container.
Incidental Storage (Small quantities) Liquids located outside of storage cabinets/areas shall not exceed: 25 Gallons of Class IA in containers. 120 Gallons of Class IB, IC or Class II liquids in containers.
Transferring of Flammable Liquids • Liquids shall be kept in covered/closed containers when actually not in use. • Open flame and smoking is strictly prohibited in transferring areas. • Liquid transfer shall be through a devise drawing through the top of the drum or by gravity through an approved self-closing valve. Transfer by air pressure is prohibited. • Containers from which flammable liquids are dispensed are to be grounded and bonded to avoid fire due to static electricity. • Flammable liquids are only to be dispensed into approved safety cans.
Use and Disposal of Flammable Liquids • Open flames, smoking, welding/brazing is prohibited in areas where flammable liquids are store, transferred, used or disposed of. • Keep containers and drums sealed when not in use. • Clean up spills! • Maintain good ventilation. • Mixing of flammable liquids is prohibited! (Mixing flammable liquids can lower their combined flashpoint.) • Rags used to apply flammable liquids are to be disposed of in a self-closing oily waste can.