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Subchapter 7. General Industry Safety Orders
Group 20. Flammable Liquids, Gases and Vapors
Article 134. Definitions
Adequate Ventilation. Ventilation which, under normal operating conditions, is sufficient to keep the concentration of a hazardous gas, vapor, mist, fume or dust below 25 percent of the lower explosive limit and sufficient to ensure that no employee is harmfully exposed.
Aerated Solid Powders. Any powdered material used as a coating material which shall be fluidized within a container by passing air uniformly from below. It is common practice to fluidize such materials to form a fluidized powder bed and then dip the part to be coated into the bed in a manner similar to that used in liquid dipping. Such beds are also used as sources for powder spray operations. The combustibility of such materials may be determined by reference to the “Standard for the Prevention of Dust Explosions in the Plastics Industry,” NFPA No. 6541982.
Aerosol. A material which is dispensed from its container as a mist, spray or foam by a propellant under pressure.
Atmospheric Tank. A storage tank which has been designed to operate at pressures from atmospheric through 0.5 psig.
Barrel. A volume of 42 U. S. gallons.
Boiling Point. The boiling point of a liquid at a pressure of 14.7 psia (760 mm). Where an accurate boiling point is unavailable for the material in question, or for mixtures which do not have a constant boiling point, for purposes of this code the 10 percent point of a distillation performed in accordance with the Standard Method of Test for Distillation of Petroleum Products, ASTM D-86-78, may be used as the boiling point of the liquid.
Boil-Over. The expulsion of crude oil (or certain other liquids) from a burning tank. The light fractions of the crude oil burn off producing a heat wave in the residue, which on reaching a water strata may result in the expulsion of a portion of the contents of the tank in the form of froth.
Bulk Oxygen System. A bulk oxygen system is an assembly of equipment, such as oxygen storage containers, pressure regulators, safety devices, vaporizers, manifolds, and interconnecting piping; which has a storage capacity of more than 20,000 cubic feet of oxygen (NTP) including unconnected reserves on hand at the site. The bulk oxygen system terminates at the point where oxygen at service pressure first enters the supply line. The oxygen containers may be stationary or movable, and the oxygen may be stored as gas or liquid.
Bulk Plant. That portion of a property where flammable or combustible liquids are received by tank vessel, pipe lines, tank car, or tank vehicle, and are stored or blended in bulk for the purpose of distributing such liquids by tank vessel, pipe line, tank car, tank vehicle, or container.
Chemical Plant. A large integrated plant or that portion of such a plant other than a refinery or distillery where flammable or combustible liquids are produced by chemical reactions or used in chemical reactions.
Closed Container. A container as herein defined, so sealed by means of a lid or other device that neither liquid nor vapor will escape from it at ordinary temperatures.
Combustible Liquid. See Liquid, Combustible.
Container. Any vessel of 60 U.S. gallons or less capacity used for transporting or storing flammable or combustible liquids.
Crude Petroleum. Hydrocarbon mixtures that have a flash point below 150 F. and which have not been processed in a refinery.
Dip Tank. A tank, vat or container of flammable or combustible liquid in which articles or materials are immersed for the purpose of coating, finishing, treating or similar processes.
Distillery. A plant or that portion of a plant where flammable or combustible liquids produced by fermentation are concentrated, and where the concentrated products may also be mixed, stored, or packaged.
Dry Spray Booth. A spray booth not equipped with a water washing system. A dry spray booth may be equipped with distribution or baffle plates to promote an even flow of air through the booth or cause deposit of overspray before it enters exhaust duct; or overspray dry filters to minimize dust or residues entering exhaust ducts; or overspray dry filter rolls designed to minimize dusts or residues entering exhaust ducts; or where dry powders are being sprayed, with powder collection systems so arranged in the exhaust to capture oversprayed material.
Electrostatic Fluidized Bed. A container holding powder coating material which is aerated from below so as to form an air-supported expanded cloud of such material which is electrically charged with a charge opposite to the charge of the object to be coated; such object is transported through the container immediately above the charged and aerated materials in order to be coated.
Fire Area. An area of a building separated from the remainder of the building by construction having a fire resistance of at least one hour and having all communicating openings properly protected by an assembly having a fire resistance rating of at least one hour.
Flammable Aerosol. An aerosol which is a flammable aerosol as defined by Section 5194 Appendix B - Physical Hazard Criteria. For the purposes of Group 20 of these Orders, such aerosols are considered Category 1 flammable liquids.
Flammable (Explosive) Limits. The percent levels, volume by volume, of a flammable vapor or gas mixed in air between which propagation of a flame or an explosion will occur upon the presence of ignition. The leanest mixture at which this will occur is called the lower flammable limit. The richest mixture at which it will occur is the upper flammable limit. The percent of vapor mixture between the lower and upper limits is known as the flammable range.
Flammable Liquid. See Liquid, Flammable.
Flash Point. The minimum temperature at which a liquid gives off vapor within a test vessel in sufficient concentration to form an ignitable mixture with air near the surface of the liquid, and shall be determined as follows:
(A) For a liquid which has a viscosity of less than 45 SUS at 100oF (37.8oC), does not contain suspended solids, and does not have a tendency to form a surface film while under test, the procedure specified in the Standard Method of Test for Flashpoint by Tag Closed Tester (ASTM D-56-05), which is hereby incorporated by reference, or an equivalent test method as defined in Section 5194, Appendix B - Physical Hazard Criteria, shall be used.
(B) The flash point of a liquid having a viscosity of 45 SUS or more at 100 F. (37.8oC), or contains suspended solids, or has a tendency to form a surface film while under test, the Standard Method of Test for Flashpoint by Pensky-Martens Closed Tester (ASTM D-93-08), which is hereby incorporated by reference, or an equivalent method as defined by Section 5194, Appendix B - Physical Hazard Criteria, shall be used except that the methods specified in Note 1 to section 1.1 of ASTM D-93-08 may be used for the respective materials specified in the Note.
(C) For a liquid that is a mixture of compounds that have different volatilities and flash points, its flash point shall be determined by using the procedure specified above on the liquid in the form it is shipped. If the flash point, as determined by this test, is 100oF. (37.8oC) or higher, an additional flash point determination shall be run on a sample of the liquid evaporated to 90 percent of its original volume, and the lower value of the two tests shall be considered the flash point of the material.
(D) Organic peroxides, which undergo auto-accelerating thermal decomposition, are excluded from any of the flash point determination methods above.
Flow Coat. The process of discharging liquids from nozzles, slots, etc. in an unatomized state onto material to be coated.
Fluidized Bed. A container holding powder coating material which is aerated from below so as to form an air-supported expanded cloud of such material through which the preheated object to be coated is immersed and transported.
Gaseous Hydrogen System. One in which the hydrogen is delivered, stored and discharged in the gaseous form to consumer's piping. The system includes stationary or movable containers, pressure regulators, safety relief devices, manifolds, interconnecting piping and controls. The system terminates at the point where hydrogen at service pressure first enters the consumer's distribution piping.
Ignition Temperature. The minimum temperature to which a flammable vapor or gas mixture in air must be heated in order to initiate or cause self sustained combustion.
Inside Storage. A room or building used for the storage of liquids in containers or portable tanks, separated from other types of occupancies. Such areas may include:
Inside room. A room totally enclosed within a building and having no exterior walls.
Cut-off Room. A room within a building having at least one exterior wall.
Liquefied Hydrogen System. One into which liquefied hydrogen is delivered and stored and from which it is discharged in the liquid or gaseous form to consumer piping. The system may include stationary or portable containers, pressure regulators, safety relief devices, manifolds, interconnecting piping and controls as required. The system originates at the storage container fill connection and terminates at the point where hydrogen at service pressure first enters the supply line.
Liquid. Any material which has a fluidity greater than that of 300 penetration asphalt when tested in accordance with ASTM Test for Penetration for Bituminous Materials, D-5-73.
Liquid, Combustible. A liquid having a flash point greater than 199.4oF (93oC) (formerly designated Class IIIB Combustible liquids).
Liquid, Flammable. Any liquid having a vapor pressure not exceeding 40 pounds per square inch (absolute) at 100oF (37.8oC) and having a flashpoint at or below 199.4oF (93oC). Flammable liquids are divided into four categories as follows:
(A) Category 1 shall include liquids having flashpoints below 73.4oF (23oC) and having a boiling point at or below 95oF (35oC).
(B) Category 2 shall include liquids having flashpoints below 73 73.4oF (23oC) and having a boiling point above 95oF (35oC).
(C) Category 3 shall include liquids having flashpoints at or above 73.4o F (23o C) and at or below 140oF (600C). When a Category 3 liquid with a flashpoint at or above 100oF (37.8oC) is heated for use to within 30oF (16.7oC) of its flashpoint, it shall be handled in accordance with the requirements for a Category 3 liquid with a flashpoint below 100oF (37.8oC).
(D) Category 4 shall include liquids having flashpoints above 140oF (60oC) and at or below 199.4oF (93oC). When a Category 4 flammable liquid is heated for use to within 30 30oF (16.7oC) of its flashpoint, it shall be handled in accordance with the requirements for a Category 3 liquid with a flashpoint at or above 100oF (37.8oC).
(E) When liquid with a flashpoint greater than 199.4oF (93oC) is heated for use to within 30oF (16.7oC) of its flashpoint, it shall be handled in accordance with the requirements for a Category 4 flammable liquid.
Liquid, Unstable (Reactive). A liquid which in the pure state or as commercially produced or transported will vigorously polymerize, decompose, condense, or will become self-reactive under conditions of shock, pressure, or temperature.
Low Pressure Tank. A storage tank designed to withstand an internal pressure above 0.5 psig but not more than 15 psig.
Outdoor Location. Outside of any building or structure, and includes locations under a weather shelter or canopy provided such locations are not enclosed by more than two walls set at right angles and are provided with vent space between the walls and vented roof or canopy.
Portable Tank. Any closed vessel having a liquid capacity over 60 U.S. gallons and not intended for fixed installation.
Pressure Vessel. Any fired or unfired vessel within the scope of the applicable section of the ASME Boiler and Pressure Vessel Code.
Refinery. A plant in which flammable or combustible liquids are produced on a commercial scale from crude petroleum, natural gasoline, or other hydrocarbon sources.
Roll Coating. The spreading and impregnating of fabrics, paper or other material by passing the material to be coated directly through a tank or trough containing flammable or combustible liquid, or over the surface of a roller that revolves partially submerged in a flammable liquid.
Safety Can. A listed container of not more than five gallons capacity, having a spring-closing lid, spout cover and a flame arrester and so designed that it will safely relieve internal pressure when subjected to fire exposure.
Service Station, Automotive. That portion of property where liquids used as motor fuels are stored and dispensed from fixed equipment into the fuel tanks of motor vehicles and shall include any facilities available for the sale and service of tires, batteries and accessories, and for minor automotive maintenance work. Major automotive repairs, painting, body and fender work are excluded.
Service Station, Marine. That portion of a property where flammable or combustible liquids used as fuels are stored and dispensed from fixed equipment on shore, piers, wharves, or floating docks into the fuel tanks of self-propelled craft, and shall include all facilities used in connection therewith.
Spray Booth A power-ventilated structure provided to enclose or accommodate a spraying operation, to confine and limit the escape of spray, vapor and residue, and to safely conduct or direct them to an exhaust system. Spray booths are manufactured in a variety of forms, including automotive refinishing, downdraft, open-face, traveling, tunnel, and updraft booths.
Spray Room. A power-ventilated fully enclosed room used exclusively for open spraying of flammable or combustible materials. The entire spray room is a spray area. A spray booth is not a spray room.
Spraying Area. Any area in which dangerous quantities of flammable vapors or mists, or combustible residues, dusts or deposits are present due to the operation of spraying processes.
A spraying area shall include:
(A) The interior of spray booths except as specifically provided in Section 5456(d).
(B) The interior of ducts exhausting from spraying processes.
(C) Any area in the direct path of spray or any area containing dangerous quantities of air-suspended powder or air-suspended combustible residue, dust, deposits, vapor or mists as a result of spraying operations.
SUS. Saybolt Universal Seconds as determined by the Standard Method of Test for Saybolt Viscosity (ASTM D-88-81), and may be determined by use of the SUS conversion tables specified in ASTM Method D2161-66 following determination of viscosity in accordance with the procedures specified in the Standard Method of Test for Viscosity of Transparent and Opaque Liquids (ASTM D445-79).
Vapor Area. Any area containing dangerous quantities of flammable vapors in the vicinity of dip tanks, their drain boards or associated drying, conveying or other equipment, during operation or shutdown periods.
Vapor Pressure. The pressure, measured in pounds per square inch (absolute) exerted by a volatile liquid as determined by the “Standard Method of Test for Vapor Pressure of Petroleum Products (Reid Method)” (ASTM D323-82).
Viscous. A viscosity of 45 SUS or more.
Waterwash Spray Booth. A spray booth equipped with a water washing system designed to minimize dusts or residues entering exhaust ducts and to permit the recovery of overspray finishing material.