Document 2jdaLVqx4NmgYvp7dyOOnvBzN

174 nTable 6. CHAPTER 10 1948 Guide Approximate Limits of Flammability of Single Gases and Vapors In Air at Ordinary Temperatures and Pressures Gas or Vapor Acetaldphvrip Acetonp Acetylene1*. Allyl alcohol... Ammonia. ' Amyl alcohol______ Amyl chloride Amylenp Benzene (benzol) Benzyl chloride- Butane. .... Butyl acetate_________ Butyl alcohol....__________ Butylene____ Carbon disulfidp ------------------------------------------- . Carbon monoxide Crotonaldehvde Cyclohexane....Cyclopropane..... Decane Dichloroethylene (1, 2)____ Diethyl selenide.__________ Dioxan. 'Ethane. Ether (diethvl) Ethyl acetate Ethyl alcohol.. Ethvl bromide Ethyl cellosolve_________ __ Ethyl chloride. Ethylene Ethylene dichloride." Ethyl formate.______ Ethyl nitrite.. Ethylene oxide.. Furfural (125 C) . Gasoline.. Heptane.. Hexane.. Hydrogen cyanide.. Hydrogen_______ Hydrogen sulfide.. Illuminating gas_ Iso-butyl alcohoL. Iso-pentane. Iso-propyl acetate.. Iso-propyl alcohol. Methaneb.________ Lower Limit Per cent by Volume 4.0 2.1 2.5 214' 16.0 1.2 1.4 1.6 1.4 1.1 1.6 1.7 1.7 1.7 1.0 12.5 2.1 1.3 2.4 0.67 9.7 2.5 1.7 2.2 3.3 6.7 2.6 3.6 3.0 6.2 2.7 3.0 3.0 2.1 1.3 1.0 1.2 5.6 4.1 4.3 5.3 1.7 1.3 1.8 2.5 5.0 Upper Limit Per cent by Volume .57 13.0 80 27.0 v ___ -- ~8.0 -- 8.5 15.0 9.6 50 74 15.5 8.4 10.3 2.6 12.8 22.2 15.0 48.0 11.5 19.0 11.3 15.7 14.8 ; 34.0 15.9 16.5 "80 6.5 6.0 6.9 40.0 74 .45.5 31.0 '7.8 15.0 Closed Cup Flash Point F Deco : . . -17 0 -, , 70 - -. " ' 91 . 12 140 , ..,-76 . 72 84 . ' ' -22 -_. 55 1 115 43 65 . -15 24 55 "l04 -58 56 -4 -31 140 -50 25 -7 0 82 43 53 Adapted from:. Limits of Inflammability of Gases and .Vapors, by H. F. Coward and G. W. Jones <17. S. Bureau of Mines. Bulletin No. 279/1939); Properties of Flammable Liquids, Gases and Solids (As sociated Factory Mutual Fire Ins. Cos., January, 1940); and National Fire Codes for Flammable Liquids, Gases, Chemicals and Explosives--1945 {National Fire protection Association). ^Turbulent mixture. ^Closed cup refers to the equipment used In flash point determinations. Air Contaminants 175 Table 6. Approximate: Limits of FlammaIbility of Single Gases and Vapors In Air at Ordinary Temperatures and Pressures (Continued) Gas or Vapor Methyl acetate. ______ Methyl alcohoL . ...--... Methyl bromide.______ ___, Methyl butyl ketone.______ Methyl chloride.____________ . Lower Limit Per cent by Volume 3.1 6.0 13.5 1.2 8.0 Methyl cyclohexane.- _..... Methyl ethyl ether.________ Methyl ethyl ketone.~~____ ; ; Methyl formate.____ _______ Methyl propyl ketone._____ 1.1 2.0 i.8 5.0 1.5 Natural gas.______ ______:__ Naphtha (benzine).-____ ...... Naphthalene............ ................. Nonane....... ........................... Octane-1____ 1_____ ................. 4.8 1.1 0.9 . 0.74 0.84 Paraldehyde.................... .......... Pentane.__________________ Propane.1__________________ Propyl acetate........____ ... Propyl alcohol:........... ............ 1.3 1.4 2.4 1.8 2.5 Propylene....................... . .. Propylene dichloride_______ Propylene Oxide..;__________ Pyridine (70 C)l.__________ ;. Toluene (toluol). ........... 2.0 3.4 2.1 1.8 13 Turpentine......._______ ____ Vinyl ether_______ ._________ Vinyl chloride.____________ __ Water gas (variable) Xylene (xylol)..................... . 0.8 1.7 4.0 6.0 1.0 Upper Limit. Per cent by . . Volume 15.5 36.5 14.5 8.0 19.7 l'o.i 11.5 22.7 8.2 13.5 6.0 ' _____ 2.9 3.2 ' 8.0 9.5 8.0 11.1 14.5 21.5 12.4 7.0 27.0 22.0 70 6.0 . Closed Cup Flash Point F Dego 15 54 __J__ _____ -- 25 -35 30 -2 ; ........-- . 20-45 174 ,- 88 ' 56 __ ._ - __ .... _____ 58 .. 59 59 ____ 68 40 . 95 * '_____ ......... 63 FLAMMABLE GASES AND VAPORS Adequate ventilation is a. primary requirement for eliminating or . minimizing the hazard of fire or explosion due to gases and vapors. The need for good ventilation is not removed by the use of other precautions, such as the elimination of known ignition sources, segregation of hazard ous operations, adoption of safe building construction, and installation of automatic alarms. . Some safety, engineers regard overventilation of an operation employing flammable liquids as a legitimate operating charge for the privilege or necessity of using a dangerous process. However, it is not possible to apply a reasonable safety factor to the ventilation estimate without consideration of the concentrations of gases or. vapors that ap proach the danger point. Safety engineers prefer to limit the concen tration to H or M of the lower explosive limit, and this fact should be given full weight, in determining the capacity and design of ventilating equipment. Rarely should consideration be given to operation. above the upper explosive limit in the open areas of buildings or. rooms--even though unoccupied--because the danger of temporary, drop of gas concentration to a point within the explosive range is too great.