Document e15mdd3BVmGNOEL1BXb2Ggjq9

, 'tv-j C.-V* Le-it * P'W ' l'-4*l, ^ . ^ * ^ Jjt lL * 'Um J, >. -f I ( f> .. > . i. ? .. $ c ^ - 'i , H C-^At^ x^ LjUf Jti+vjt*. *1 Aft . f iHajy'-L ' *4-. Requirements for the Hygienic Control of the Manufacture, *1'';'',: Distribution and Use of Lead Tetraethyl for the Preparation of Motor Fuel. Foreword The hygienic control of operations involving the production or use of lead tetraethyl differs from that required, in the more common lead trades, in that there is serious danger of exposure to a liquid organic lead compound, as well as to inorganic lead compounds* Exposure to lead tetraethyl arises from the. volatility of this compound and also from its absorbability through the healthy unbroken skin. Its vapor pressure is such that under the conditions of equilibrium at 25C, a concentration of approximately 5 mgm. of lead per liter of air will exist. Its absorption through the skin occurs at such a rate that it must be removed from the skin (best done with kerosene) within fifteen minutes of contact, if appreciable and even dangerous (dependent upon the area of skin involved) absorption is to be avoided. For these reasons it is essential that all steps of the processes of manufacture, transportation, storage, and Intro duction into gasoline be surrounded by such safeguards as will prevent exposure until the material has been diluted with gasoline to the concentrations which, in commercial motor fuels, have been shown to be safe. Manufacturing operations Involving the presence of lead dust and fume must be rendered safe by the customary methods of segregation of dusty spaces and equipment, by the use of properly designed containers for the handling of lead-bearing materials, and --2 by cleansing floors and the outside of equipment at frequent and regular intervals by methods that will not disseminate dust. All vents and stacks from furnaces and buildings, must-be so situated or so dealt with as to prevent^contamination of the general atmospheres I. Manufacture. . Safety depends basically upon the use of proper equipment* Hygienic and medical supervision is a necessary ad junct. Th following constitute minimum requirements for safe operation. 1, The concentration of lead 'in the air around workmen, '' under operating conditions, whether from dust, furie, or vapor, must not exceed 2 mgm* par 0 cubic meters of air for more than short periods, and the average concentration during the working day must not exceed 1*5 nigm. per 10 cubic meters* This may be achieved only by the U3e of properly designed equipment, by good house-keeping, and by adequate ventilation* The requirements will vary with the kind and size of .the plant* 2 The manufacturing equipment must be so constructed as to withstand the normal conditions of use, a and adea*u&te *o res sure releases or safety disks, venting to the outside of the building, must be provided where indicated for emergency purposes. 3* Two kinds of ventilation must be provided by systems which are completely separate so that the one cannot connect with the other* (a) General ventilation must maintain adequate change in the general atmosphere of the buildings to meet the requirements of the specifications for the lead content of such atmosphere. - 3- (b) Local or -unit ventilation of such equipment as may give rise to frequent or regular leakage of dust, fume or vapor, as over melting pots, casting molds* around the packing of pumps, 'along^shafts or joints, and at openings used in loading or emptying operations* ij..-Continuously or frequently collected samples of the air of all working spaces must be analysed for-their lead,content, as a check upon the operating conditions. _ 5* Positive-pressure air-line respirators must be available throughout the plant to provide protection during emergencies, repair operations, and at such times as it may be necessary to enter any space or area of the plant in which lead compounds may 'A -' ' t>e present in unsafe concentrations in the air.^ _ -- -- . 6. A detailed system of operating and safety procedure for the process and for maintenance and repair operations, should be provided for workmen, and adequate individual instructions and general supervision must be provided to ensure familiarity and ' compliance with such procedure* 7* Toilet facilities, and emergency showers, together with an adequate supply of kerosene for the prompt removal of any lead tetraethyl that may come in contact with the skin, must be provided at easily accessible locations* 8* Clean clothing from the skin out, must be furnished, daily, to all workmen. Immediately, after any actual or suspected skin contact with lead tetraethyl the exposed part of the body must be cleansed thoroughly with kerosene, then with soap and water. Con taminated clothing must be replaced at once. All clothing must be changed at the end of the working day and a bath must be taken* .9 Incidental hazards arising from the use of inflammable or corrosive materials require special safeguards. Inflammable materials should not be stored in the main operating building or buildings, and should be amply protected against leakage and fire hazard. 10* All wastes from the plant must be confined or treated or diluted sufficiently to prevent^contamination of adjacent soils or streams* ' 11* Slag, used equipment, and other materials that have been contaminated with lead tetraethyl must be destroyed, buried, or otherwise disposed of, so as to prevent danger to uninformed persons* 12* All lead tetraethyl intended "for use in fuels must contain a sufficient amount of dye to color it brightly and to color definite ly the finished motor fuel* 13* Medical supervision of all workmen must be provided* At a minimum, this shall consist of an initial examination, and periodic examinations of all potentially e^p osed employees at intervals of not more than three months, in the case of those exposed only to Inorganic lead compounds, and not more than one month, in the case . of those exposed to lead tetraethyl. Complete records shall be-kept of the examinations, which must include a complete medical history of each employee, such physical examination as is necessary to establish his physical and hygienic status, the determination of the hemoglobin, a quantitative count of stippled erythrocytes (or an equivalent procedure) and a clinical urinalysis. lip* At intervals of not more than six months, analytical studies should be carried out on a group of employees selected to represent all phases of the conditions of exposure. This should be J M ^ mm- continued at least until such time as the operating conditions have been stabilized into a demonstrably safe regime. II. Transportation. Containers'of lead tetraethyl shall be labeled as to exact content and danger, and shall conform to the regula tions of the Interstate Commerce Commission and the Bureau of Explosives. Empty containers must be closed tightly, and returned _ to the manufacturer in accordance with the existing regulations of the Interstate Commerce Commission and the Bureau of Explosives. III. Storage . All storage of lead tetraethyl outside the manufacturing plant must be in locked and adequately ventilated (natural or artificial) enclosures. Except in the case of specially designed storage and mixing equipment, the original shipping con tainers must be employed for storage. IV. Mixing Motor Fuels. 1. The maximum content of lead tetraethyl In commercial motor gasoline shall be in the proportion of 1: 1260 by volume for commercial lead tetraethyl, or 1: 1300 for PbiCsH^)* C.P. 2. Mixing lead tetraethyl with gasoline, except for certain specific requirements such as research, military and naval use, and air-mail service, shall be done only at gasoline distribution points at which properly designed mixing equipment has been installed for that purpose. . 3. Except under conditions which must be defined in detail, mixing equipment for emptying drums of lead tetraethyl must be so -6 designed as to empty the entire contents of one or more standard shipping containers into a tank of gasoline, and to thoroughly mix that quantity of lead tetraethyl into such a volume of gasoline as to provide a final and uniform concentration of lead tetraethyl not in excess of that specified above. Ij.. Lead tetraethyl, and fluids containing lead tetraethyl in high concentrations^ must not he mixed with gasoline in tank trucks, .tank-cars and other mobile equipment for transporting gasoline, except under conditions which must be defined in dtail. 5* The mixing of lead tetraethyl with gasoline must be carried out by men who are thoroughly instructed in the dangers of this work and in the means of avoiding such danger, and who are maintained under adequate hygienic and medical supervision. 6* T h e 'rulesfand instructions affecting the miking personnel shall be posted in a conspicuous place where the mixing is carried out. 0009186