Chapter 7 SAFETY IN THE LABORATORY INTRODUCTION Laboratory settings present special safety problems because of the large number of different chemicals that are often handled. Many chemicals are often incompatible, and fall into such categories as flammable materials, combustible products, water reactive and unstable, compressed gases, pyrophoric, cryogenic, corrosive, explosive, and toxic. Safe management practices require attention be given to special handling and storing of these materials, as well as proper disposal. This chapter focuses on safe handling practices for common laboratory environments. Examples of specific chemicals and proper handling practices are reviewed, and specific recommendations for a number of common chemicals encountered in laboratories are provided. The Web sites noted in the last chapter are a good source for obtaining the MSDSs of many of the chemicals discussed in this chapter. COMPRESSED AND LIQUEFIED GASES Compressed and liquefied gases should be used and handled only by properly trained personnel. Some of the most widely used gases in a laboratory are acetylene, hydrogen, methane, propane, carbon monoxide, and natural gas. This section describes the hazardous properties of these gases and provides recommendations for gas storage and handling. Table 1 provides some properties of common flammable gases. Other sources of information on gases include MSDSs, the Matheson Gas Data Book, Compressed Gas Association pamphlets such as, C-6, "Standards for Visual Inspection of Steel Compressed Gas Cylinders" and C-8, "Standard for Re-qualification of DOT-3 lit Seamless Steel 381 Copyright © 2001 Marcel Dekker, Inc. 382 CHAPTER 7 Cylinders," and NFPA publications. The MSDSs and the Matheson Gas Data Book deal chiefly with properties and use of gases and components of gas systems; pamphlets from the Compressed Gas Association deal with standards and requirements of the Department of Transportation. The NFPA "National Fuel Gas Code" describes appropriate containers and components, and the NFPA Fire Protection Guide on Hazardous Materials is a complete treatise. Table 1. Properties of Common Flammable Gases Gas Acetylene Ammonia Arsine Carbon Monoxide Diborane (pyrophoric) Hydrogen Hydrogen Sulfide MAPP Methane Natural Gas Propane Silane (pyrophoric) Exposure Limit TWA (ppm) -b 25 0.05 25 0.1 -b 10 1000 -b -b -b 5 IDLH (ppm) - 500 6 1500 40 - 300 15000 - - 20000 Flammable Limits in Air 2.5-100° 16-25 4.5-64 12.5-75 0.9-98 4-75 4.3-46 3.5-11 5-15 4-17 2-9.5 - Ignition Temperature °C 260 850 230" 593 N/A 8 566 260 - 538 538 449 N/A g Minimum Spark Ignition Energy (mJ) a 0.02 14 - - N/A 8 0.02 - - 0.3 0.5 0.3 N/A E Vapor Density [0°C) 1 atm.] air = 1 0.91 0.60 2.69 e 0.97 0.95 0.07 1.19 f - 0.55 0.5 1.52 C 1.2 e a - Human body static charge can easily exceed 3 mJ; b - Acts as a simple asphyxiant; c - Can violently decompose under pressure, even in the absence of air; d - Decomposes; e - Reference temperature of 70 "F (21.1 °C); f - Reference temperature of 59 "F (15 °C); g - The chemical ignites spontaneously. Copyright © 2001 Marcel Dekker, Inc. SAFETY IN THE LABORATORY 383 Compressed Gases Storage Areas The following describes the requirements for compressed gas storage areas. Storage of toxic gases should be evaluated to ensure the safety of building occupants and the public. Storage areas should be prominently posted with the hazard class, or the name of the gas, and with "NO SMOKING" signs where appropriate. Designated storage areas in parts of the laboratory containing hazardous/compressed gases should be prominently posted with the names of the gases being stored. Where hazardous/compressed gases of different types are stored at the same location, containers should be grouped by types of gas. Full and empty containers should be stored separately with the storage layout so planned that containers comprising old stock can be removed first with a minimum handling of other containers. Compressed gas cylinders should not be stored near readily ignitable substances (e.g., gasoline or waste), or near combustibles in bulk, (e.g., oil). Compressed gas cylinders should not be exposed to continuous dampness and should not be stored near salt or other corrosive chemicals or fumes. Corrosion may damage the containers and may cause the valve protection caps to stick. Compressed gas cylinders should be protected from any object that will produce a cut or other abrasion in the surface of the metal. Compressed gas cylinders should not be stored near elevators, gangways, or unprotected platform edges, or in locations where heavy moving objects may strike or fall on them. Users should store compressed gas cylinders standing upright where they are not likely to be knocked over. Properly secured gas cylinders less than 305 in 3 water volume may be stored horizontally. Compressed gas cylinders in public areas should be protected against tampering. Outdoor: Compressed gas cylinders may be stored in the open but should be protected from the ground beneath to prevent bottom corrosion. Containers may be stored in the sun; however, if the supplier recommends storage in the shade for a particular gas, the recommendation should be observed. Outdoor storage areas should have a minimum of 25 percent of the perimeter open to the atmosphere; the open space may be covered with chain link fence, lattice construction, open block, or similar materials. Storage areas should be kept clear of dry vegetation and combustible materials for a minimum distance of 15 feet. Storage areas should be provided with physical protection from vehicle damage. Storage areas can be covered with canopies of noncombustible construction. Indoor: Gas cylinders should be separated according to their category. Refer to Table 2. Storage rooms for compressed gases should be well ventilated and dry. Where practicable, storage rooms should be of fire-resistive construction. Floors and shelves should be of noncombustible or limited combustible construction. Copyright © 2001 Marcel Dekker, Inc. 384 CHAPTER 7 Storage room temperatures should not exceed 130°F (54°C). Storage in subsurface locations should be avoided in order to avoid creating hazardous conditions such as confined spaces or difficulty in fire fighting. Compressed gas cylinders stored inside should not be located near exits, stairways, or in areas normally used or intended for the safe exit of people. Maximum size and quantity limitations for compressed or liquefied gas cylinders in laboratory work areas are summarized in Table 3. Table 2. Separation of Gas Cylinders by Hazard Gas Hazard Toxic Pyrophoric Flammable Oxidizing Non- flammable Non- flammable Compatible Compatible Compatible Compatible - Oxidizing 20ft* 20ft* 20ft* - Compatible Flammable 20ft* 20ft* - 20ft* Compatible Pyrophoric 20ft* - 20ft* 20ft* Compatible Toxic - 20ft* 20ft* 20ft* Compatible Note - Compatible cylinders may be stored adjacent to each other. * = The 20 ft distance may be reduced without limit when the cylinders are separated by a barrier of noncombustible materials at least 5 feet high having a fir resistance rating of at least '/2 hour. Table 3. Size/Quantity Limitations for Compressed or Liquefied Gas Cylinders Type Material Flammable Gases or Oxygen Liquefied Flammable Gases Gases with Health Rating of 3 or 4 (NFPA) Maximum Cylinder Size 8 10x50 9x30 5x15 Maximum number of cylinders per 500 ft 2 or less Non-sprinklered 3 2 3 Sprinklered 6 3 - a - Approximate dimensions in inches (Diameter X Length) Copyright © 2001 Marcel Dekker, Inc. SAFETY IN THE LABORATORY 385 Compressed and Liquefied Gas Cylinders The following are recommended requirements for compressed gas cylinders. Cylinders should be: • Labeled and marked in accordance with DOT and 29 CFR 1910.1200 • Maintained by trained personnel. Cylinders should also be inspected by users for the following: legible marking and labeling; absence of defects; within the hydrostatic test date. Users should not modify, tamper with, or repair any part of a container or cylinder. The cylinders should have visual and other inspections performed by gas plant personnel. Gas plant personnel should also ensure that safety relief devices for compressed gas cylinders are properly installed and maintained. Cylinders should be used to contain and use the contents. They should not be used for any other purpose. A static pressure test and soapy water can be used to determine the presence and location of leaks from piping systems. Manifolds should be of proper design for temperatures, pressures, and flows of the materials they contain. Operations involving experimental manifolds must have established SOPs (standard operating procedures). Cylinders should be secured in place to prevent falling. Cylinders should not be placed where they might become part of an electric circuit. Cylinders should not be exposed to temperature extremes, i.e., 125°F. If ice or snow accumulate on a container, thaw at room temperature or with water not exceeding 125°F. Cylinders that are not necessary for current laboratory operations should be stored in a safe area outside the laboratory work area. Cylinders should be visually inspected by users for signs of physical damage. Containers that have been damaged, or are leaking, defective, or corroded, should be returned to the gas plant. Valve protection caps should be used at all times except when containers are secured and in use. Valves should be kept closed at all times except when in use. Valve outlets should be pointed away from personnel when being opened. Hand-wheel valves should be opened slowly. Those valves without hand wheels should be opened with a wrench designed or approved for that purpose. Cylinders containing toxic gases having a health rating of 3 or 4, or a health rating of 2 and no warning properties, should be kept in a continuously, mechanically ventilated enclosure. There should be no more than 3 cylinders per enclosure, or fewer depending upon the ventilation capacity. Gas tight valves on poison gas containers should be checked and tightened prior to return to the gas plant. Cylinders in storage containing gases that are corrosive to cylinder valves or that may become unstable while stored in the cylinder Copyright © 2001 Marcel Dekker, Inc. 386 CHAPTER 7 should have a maximum retention period of 6 months, unless a shorter period is otherwise specified by the manufacturer. Transfer of compressed gases from one container to another should only be performed by trained, authorized personnel. Empty and full cylinders must be segregated. Empty cylinders must be tagged "empty." Nonliquefied compressed gas containers should not be emptied below the operating pressure of the system, or not less than 20 psig to prevent backflow of atmosphere or other contaminants. All liquefied gas containers, except those designed for horizontal use, should be stored and used valve end up. Nonflammable liquefied gas containers may be inverted for use if secured and dispensed with an apparatus designed for inverted use. Regulators and Check-Valves: Threads on regulator connections or other equipment should match those on container valve outlets. Connections that do not fit should not be forced. Check valves should be used, inspected, and regularly maintained where a container may be contaminated by backflow of process materials. "Needle" valves are not designed to control the full cylinder pressure. When finished dispensing the gas, it is good practice to leave the needle valve open after closing the cylinder valve. In the event of a leak through the cylinder valve, this arrangement prevents build-up of dangerous pressure in the regulator and needle valve assembly. Note, however, that the released gas may pose other hazards. All connections must be gas tight. Tightening, repairs, or removal of the regulator should not be performed while the system is under pressure. Regulators used for toxic gases that are not in service should be stored in plastic bags and labeled with the name of the gas they were used to regulate. Only regulators designed for the particular use and gas should be used. Noncryogenic liquefied gases with relatively low vapor pressures at low ambient temperature may require check valves. Transportation and Disposal: A suitable hand truck, forklift, or appropriate material handling device should be used to move containers/cylinders. Never lift containers/cylinders by using the container cap or magnets. Ropes, chains, or slings should only be used to suspend containers that have been designed as such. Compressed gas containers/cylinders that are not at or near atmospheric pressure should be handled as hazardous waste and disposed of in accordance with local, state and federal regulations. Compressed and Liquefied Gas Piping Systems Piping systems for compressed and liquefied gases should comply with the requirements of applicable NFPA standards: - NFPA 50, "Standard for Bulk Copyright © 2001 Marcel Dekker, Inc. SAFETY IN THE LABORATORY 387 Oxygen Systems at Consumer Sites." - NFPA 50a, "Standard for Gaseous Hydrogen Systems at Consumer Sites." - NFPA 50b, "Standard for Liquefied Hydrogen Systems at Consumer Sites." - NFPA 51, "Standard for the Design and Installation of Oxygen-Fuel Gas Systems for Welding, Cutting, and Allied Processes." - NFPA 54, "National Fuel Gas Code." - NFPA 58, "Standard for the Storage and Handling of Liquefied Petroleum Gases." Systems for other compressed gases and for cryogenic materials should comply with the manufacturer's design and specifications. Manual shut-off valves should be provided at each point of supply and each point of use. Exception: The following are exceptions to the above recommended guidelines: • If containers supplying the piping system are equipped with shut-off valves, a separate valve is not required. • A valve at the point of use is not required if there is a supply shut-off valve within immediate reach of the point of use. All portions of a piping system should have uninterruptible pressure relief. • Piping designed for a pressure greater than the maximum system pressure that can be developed under normal conditions. Pressure relief systems should be designed to provide a discharge rate sufficient to avoid further pressure increase and should vent to a safe location. Permanent piping should be identified at the supply point and at each discharge point with the name of the compressed or liquefied gas being transported. Piping systems, including regulators, should not be used for gases other than those for which they are designed and identified. • A piping system can be converted from one gas service to another after a thorough review of design specifications, materials of construction, service compatibility, and other appropriate modifications. Acetylene [C 2 HJ Acetylene is highly ignitable and explosive. Explosive limits are 2.5 to 100%. Note that the gas not only has a low value LEL, but has a wide range - making it extremely dangerous. Acetylene is highly unstable at high pressures and may decompose into hydrogen and carbon with explosive violence if subjected to sparks, heat, or friction. Commercial grade acetylene has a characteristic garlic- like odor. Acetylene cylinders should be stored and used with the valve end up. Storage of acetylene cylinders valve end up will minimize the possibility of solvent (acetone or another suitable acetylene solvent) being discharged. ("Valve end up" includes Copyright © 2001 Marcel Dekker, Inc. 388 CHAPTER 7 conditions where the container axis may be inclined as much as 45 degrees from the vertical.) Protect against lightning and static electricity. Isolate from oxidizing gases, especially chlorine. Laboratory handling, storage, and utilization of acetylene in cylinders should be in accordance with Compressed Gas Association (CGA) Pamphlet G-l. Piping systems for transfer and distribution of acetylene should be designed, installed, maintained, and operated in accordance with CGA Pamphlet G-l.3. Generation and charging (filling) of acetylene cylinders should be in accordance with CGA Pamphlet G-l.4. Hydrogen [H 2 ] Hydrogen includes the isotopes deuterium [2 H 2 or D 2 ] and tritium [3 H 2 or T 2 ]. Hydrogen has a wide range of explosive limits (4-75%) and readily disperses and stagnates in the vicinity of the ceiling. Hydrogen may explode by sunlight when mixed with halogen gases. Hydrogen bums with an (almost) invisible flame so a fire is difficult to detect. Hydrogen rapidly diffuses through porous materials. It can leak out of systems that are considered gastight for air or other common gases at equivalent pressures. Hydrogen can cause flaking, hydrogen embrittlement, or delayed brittle fracture when absorbed into steel. Trace amounts of hydrogen sulfide, cyanide, and arsenic can greatly increase the amount of hydrogen that becomes absorbed by steel. Under corrosive conditions, these substances can contribute to severe hydrogen damage, leading to loss of strength in the steel. Tritium is the radioactive isotope of hydrogen, and is used in research laboratories for specialty applications. Tritium is a low energy emitter (0.018 MeV) with a half-life of 12.26 years (approx. 5% loss each year). It readily exchanges with hydrogen in water, forming tritiated water that disperses uniformly throughout body tissue. The use and storage of hydrogen are outlined under 29 CFR 1910.103 for gaseous and liquid hydrogen. Hydrogen gas detectors are most effective when placed near the ceiling, since this is where the gas will collect. FLAMMABLES AND COMBUSTIBLES The classification of flammable and combustible liquids is based primarily on the fire characteristics of the chemical, particularly the flashpoint. Quantity Copyright © 2001 Marcel Dekker, Inc. SAFETY IN THE LABORATORY 389 limitations, classes of flammable and combustible liquids, maximum allowable size of containers and portable tanks, and common flammable and combustible compounds are detailed in Tables 4 through 7. Attention should also be paid to such fire properties as the auto ignition temperature, flammability range, upper and lower explosion limits. Also, users should focus on the compatibility of different chemicals, since combinations of certain chemicals can lead to spontaneous combustion situations or other fire hazard risks. Table 4. Recommended Quantity Limitations Offices: All storage of flammable and combustible liquids prohibited except for that required for maintenance and operation of the building or operation of equipment. In such cases, liquid should be kept in closed metal containers and stored in a storage cabinet, a safety can, or in an inside storage room that does not have a door opening into the portion of the building used by the public. Laboratories: 5 gal/100 ft 2 of floor space for flammable liquids and combustible liquids not in safety cans and flammable liquid storage cabinets; 10 gal/100 ft 2 (includes quantities in safety cans and flammable liquid storage cabinets) Other Experimental, Operation, and Warehouse Areas: 25 gal (does not include storage in flammable liquid storage cabinets) Outdoor Areas: 20 drums or 1100 gal. of flammable and/or combustible liquid Table 5. Classes of Flammable and Combustible Liquids Flammable Flashpoint < 100 °F (37.8 °C) Vapor Pressure < 40 psia Class 1A Flashpoint < 73 °F (22.8 °C) and Boiling point < 100 °F (37.8 °C) Class IB Flashpoint < 73 °F (22.8 °C) and Boiling point >100°F (37.8 °C) Class 1C Flashpoint 73 °F (22.8 °C) and < 100 °F (37.8 °C) Combustible Flashpoint >100 °F (37.8 °C) Class II Flashpoint 100 °F (37.8 °C) and < 140 °F (60 °C) Class IIIA Flashpoint 140 °F (60 °C) and < 200 °F (93.3 °C) Class IIIB Flashpoint >200 °F (93.3 °C) Copyright © 2001 Marcel Dekker, Inc. 390 CHAPTER 7 Table 6. Maximum Allowable Size of Containers and Portable Tanks. Container Type Glass or approved plastic Metal (other than DOT drums) Safety cans Metal drums (DOT spec.) Approved portable tanks Flammable Liquids IA 1 pt* Igal 2 gal 60 gal 600 gal IB 1 qt* 5ga. 5 gal 60 gal 600 gal 1C Igal 5 gal 5 gal 60 gal 600 gal Combustible Liquids II Igal 5 gal 5 gal 60 gal 600 gal III Igal 5 gal 5 gal 60 gal 600 gal * Glass, 1 gal containers are generally prohibited for class IA or IB flammable liquids, but they may be used if (a) a metal or approved plastic container would contaminate the liquid; (b) the liquid would corrode a metal container; or (c) a single assay lot or more than the listed amount is required. In general, it should be noted that: 1. Outdoor container and portable tank storage should comply with Tables H-16 and H-17 of 29 CFR 1910.106, respectively. 2. Indoor container and portable tank storage should comply with Tables H-14 and H-15 of 29 CFR 1910.106, respectively. 3. Storage in inside rooms should comply with requirements of Table H-13 of 29 CFR 1910.106. 4. Supply piping should comply with NFPA 30, "Flammable and Combustible Liquids Code." For specific storage criteria the reader should carefully review 29 CFR 1910.106. Table 7 provides the reader with the classification system used in the United States for flammable and combustible liquids. More extensive data for a large number of different chemical compounds can be found in the Handbook of Industrial Toxicology and Hazardous Materials, Marcel Dekker, Inc.(1999). Copyright © 2001 Marcel Dekker, Inc. [...]... 130 4-2 9-6 Bromine 77 2 6-9 5-6 Calcium chlorate 1013 7- 7 4-3 Calcium hypochlorite 77 7 8-5 4-3 Chlorine trifluoride 77 9 0-9 1-2 Chromium anhydride 133 3-8 2-0 Chromic acid 77 3 8-9 4-5 1353 0-6 8-2 Dibenzoyl peroxide 9 4-3 6-0 Fluorine 77 8 2-4 1-4 Hydrogen peroxide 77 2 2-8 4-1 Magnesium perchlorate 1003 4-8 1-8 Nitric acid 76 9 7- 3 7- 2 Nitrogen peroxide 1010 2-4 4-0 Copyright © 2001 Marcel Dekker, Inc 404 CHAPTER 7 Table 9 Continued... Nitrogen trioxide 1203 3-4 9 -7 1054 4 -7 3 -7 Perchloric acid 76 0 1-9 0-3 Potassium bromate 77 5 8-0 1-2 Potassium chlorate 381 1-0 4-9 Potassium perchlorate 77 7 8 -7 4 -7 Potassium peroxide 170 1 4 -7 1-0 Propyl nitrate 62 7- 1 3-4 Sodium chlorate 77 7 5-0 9-9 Sodium chlorite 77 5 8-1 9-2 Sodium perchlorate 76 0 1-8 9-0 Sodium peroxide * - Chemical Abstracts Service Registry Number 131 3-6 0-6 CARCINOGENS, HIGHLY TOXIC CHEMICALS, AND... Toluene 10 8-8 8-3 39 4 IB 7 1-5 5-6 30 -1 IB 1, 1 ,2-trichloroethane 7 9-0 0-5 90 32 1C 1, 1, 1 -trichloroethylene 7 9-0 1-6 90 32 1C 1,1,1 -Trichloromethane [Chloroform] 6 7- 6 6-3 - Chemical Name Petroleum Ether [Petroleum Spirits] 1,1,1 -trichloroethane [Methylchloroform] Xylene, Mixed (m-, o-, p-) 133 0-2 0 -7 8 1-9 0 m- 10 8-3 8-3 0P- Nonflam 2 7- 3 2 1C 77 25 1C 9 5-4 7- 6 63 17 IB 10 6-4 2-3 77 25 1C * - Chemical Abstracts... methyl ketone peroxide 133 8-2 3-4 Butyl perbenzoate 61 4-4 6-9 Ethyl nitrate 62 5-5 8-1 tert-Butyl peroxyacetate 10 7- 7 1-1 Hydroxylamine 78 0 3-4 9-8 tert-Butyl peroxypivalate 92 7- 0 7- 1 Peroxyacetic acid 7 9-2 1-0 l-Chloro-2,4dinitrobenzene 9 7- 0 0 -7 Picric acid 8 8-8 9-1 Cumeme hydroperoxide 8 0-1 5-9 Trinitrobenzene Diacetyl peroxide 11 0-2 2-5 Trinitrotoluene [TNT] 9 9-3 5-4 25 37 7- 3 2-6 11 8-9 6 -7 Pyrophoric Materials Pyrophoric.. .SAFETY IN THE LABORATORY Table 7 Flammable/Combustible Classification of Common Liquids Flashpoint CASRN* °F °C Class Acetone 6 7- 6 4-1 -2 -1 9 IB Acetic Acid 6 4-1 9 -7 109 43 II Acetonitrile 7 5-0 5-8 43 6 IB Aniline 6 2-5 3-3 158 70 IIIA Benzene 7 1-4 3-2 12 -1 1 IB Butyl Alcohol, 7 1-3 6-3 84 29 1C sec- 7 8-9 2-2 75 24 1C tert- 7 5-6 5-0 52 11 IB Carbon Disulfide 7 5-1 5-0 -2 2 -3 0 IB Carbon Tetrachloride 5 6-2 3-5 -. .. Tetrachloride 5 6-2 3-5 - - Nonflam Noncomb Chloroform 6 7- 6 6-3 - - Nonflam Noncomb Diethyl Ether [Ethyl Ether] 6 0-2 9 -7 -4 9 45 IA Diisopropyl Ether 10 8-2 0-3 -1 8 -2 8 IB N,N ' -Dimethyl-formamide [DMF] 6 8-1 2-2 135 57 II 1 ,4-Dioxane 12 3-9 1-1 54 12 IB Ethyl Alcohol 6 4-1 7- 5 54 12 IB Ethylene Glycol 10 7- 2 1-1 232 111 IIIB containing 6 % methanol 5 0-0 0-0 162 72 IIIA containing 10% methanol 5 0-0 0-0 1 47 64 IIIA containing... 5 0-0 0-0 122 50 II Isoamyl Alcohol-Primary [Isopentanol] 12 3-5 1-3 109 43 II Chemical Name Copyright © 2001 Marcel Dekker, Inc 391 CHAPTER 7 392 Table 7 Continued Flashpoint CASRN* °F °C Class Isopropyl Alcohol 6 7- 6 3-0 54 12 IB Methyl Alcohol 6 7- 5 6-1 52 11 IB Methyl Ethyl Ketone 7 8-9 3-3 21 -6 IB Pentane 10 9-6 6-0 -4 0 40 IA 64 47 5-8 5-0 < 0 . Alcohol-Primary [Isopentanol] CASRN* 6 7- 6 4-1 6 4-1 9 -7 7 5-0 5-8 6 2-5 3-3 7 1-4 3-2 7 1-3 6-3 7 8-9 2-2 7 5-6 5-0 7 5-1 5-0 5 6-2 3-5 6 7- 6 6-3 6 0-2 9 -7 10 8-2 0-3 6 8-1 2-2 12 3-9 1-1 6 4-1 7- 5 10 7- 2 1-1 5 0-0 0-0 5 0-0 0-0 5 0-0 0-0 12 3-5 1-3 Flashpoint °F -2 109 43 158 12 84 75 52 -2 2 - - -4 9 -1 8 135 54 54 232 162 1 47 122 109 °C -1 9 43 6 70 -1 1 29 24 11 -3 0 - - 45 -2 8 57 12 12 111 72 64 50 43 Class IB II IB IIIA IB 1C 1C IB IB Nonflam. Noncomb. Nonflam. Noncomb. IA IB II IB IB IIIB IIIA IIIA II II Copyright. p-) m- 0- P- CASRN* 6 7- 6 3-0 6 7- 5 6-1 7 8-9 3-3 10 9-6 6-0 64 47 5-8 5-0 10 9-9 9-9 10 8-8 8-3 7 1-5 5-6 7 9-0 0-5 7 9-0 1-6 6 7- 6 6-3 133 0-2 0 -7 10 8-3 8-3 9 5-4 7- 6 10 6-4 2-3 Flashpoint °F 54 52 21 -4 0 < 0 7 39 30 90 90 - 8 1-9 0 77 63 77 °C 12 11 -6 40 < ;-1 8 -1 4 4 -1 32 32 2 7- 3 2 25 17 25 Class IB IB IB IA IB IB IB IB 1C 1C Nonflam. 1C 1C IB 1C *. -trichloroethane [Methylchloroform] 1, 1 ,2-trichloroethane 1, 1, 1 -trichloroethylene 1,1,1 -Trichloromethane [Chloroform] Xylene, Mixed (m-, o-, p-) m- 0- P- CASRN* 6 7- 6 3-0 6 7- 5 6-1 7 8-9 3-3 10 9-6 6-0 64 47 5-8 5-0 10 9-9 9-9 10 8-8 8-3 7 1-5 5-6 7 9-0 0-5 7 9-0 1-6 6 7- 6 6-3 133 0-2 0 -7 10 8-3 8-3 9 5-4 7- 6 10 6-4 2-3 Flashpoint °F 54 52 21 -4 0 <