Document qkXjBGwZN645vK9wgv78XgKVK

Report on Observations Made At The American Crucible Products J orapany*a Plant; at Lorain Ohio Conditions existing in the operation of the furnace, casting and cleaning rooms of the plant of The American Crucible Products Company at Lorain, Ohio viero observed on February $ Particular attention was paid to operations having potential health hazards because of the presence of lead fumes and dusts of lead compounds in the atmosphere. These operations were examined in a cursory manner by the analysis of particulate material collected from the atmosphere by means of a filter-paper technique* The filter-paper technique, rather than the more reliable electrostatic precipitation of particles from the air, was used because the former was the more convenient and satisfactory for obtaining preliminary information concerning the conditions at the plant. It should be borne in mind that the data so obtained during this visit are merely illustrative rather than representative of the average or regular conditions of exposure to lead. Procedure The equipment used to collect samples from the atmosphere consisted of an aluminum cone in which two 'batman #t*0 filter papers could be placed so as to expose a surface area of about 11 cm* in diameter to a stream of air. Suction to draw the air through the papers was Kg 0021677 providad by th pump of a small equipment designed for field use One cubic foot of air per minute can be drawn through the apparatus when the crank of the pump is rotated at the rate of approximately rpa* The volume of air sampled was determined from the total number of revolutions of the crank and a calibration chart which related revolutions per minute to revolutions per ou ft* The lead determinations were made by means of a colorimetric method which is baaed on the use of nlthlfcone under conditions which ensure specificity for lead* Heaults and Discussion The quantities of lead removed from the air In the vicinity of the various operations which were studied are listed in Table 1* It is apparent from the data that definite conclusions concerning variations In the lead concentration which may arise from variations in the movement of the air in the several areas of the plant (variations in state of windows, etc*) cannot be determined from tests made on any single day* Moreover fortuitous or changing factors such as differences in the operations and in the production schedules must also be considered in the total picture* Variations in any on of these factors may be sufficient to account for the small differences observed between the two series of samples 0021678 5 taken on February 9 The data demonstrate the occurrence of excessive concentrations of lead in the air in the vicinity of all of the operations which were studied. (Values far in excess of 1*5 g* of lead (?b) per 10 M, should not be permitted to exist in the atmosphere of working establishments for more than a few minutes at a time* and the average value daily should not exceed this figure*} In the case of the foundry, air is drawn into the area through doors and windows by fans set in bays in the ceiling of the foundry* It is a well established fact fclmfc such general ventilation is often found to be unsatisfactory for the removal of toxic dusts and fumes by dilution, principally because excessive volumes of air must be used even when the atmosphere is only moderately contaminated* Local exhaust ventilation systems, so applied as to capture fume and dust at their points of origin are much more economical and affective# One of the difficulties of the general ventilation of this foundry is that the air moves through and away from moat of the working stations toward the ceiling, generally passing through the breathing son of the worker who frequently m e t stand or bend directly over his work* This is particularly true of the "unit shakeout", where the highest concentrations of lead were found* An other location at which an excessive lead concentration was found was at the "core knockout", where again, the K 0021679 operator stands directly over his work while clust and fume move through his breathing one to the fan in the roof# The concentration of lead in the sir near the cut-off machine in the cleaning area is also excessive# Inspection of the entire cleaning area indicated that the housekeeping in this area is poor, there being piles of filings and dust on the equipment as well as on the floor# Some of the abrasive wheel cleaners in this area are adequately exhausted, but much grinding of small objects is carried on without the aid of local exhaust ventilation at a large table in the center of the room* since the alloys handled, in this room are probably all of the same type it is logical to expect that the concentration of lead in the atmosphere in the entire area would not differ too much from that found near the gate cut-off machine* The latter machine is locally exhausted but apparently ineffectually# Part of the difficulty is due to the fact that the suction opening is at least 18 inches from the cutting edge of the wheel and the velocity of the air at the wheel itself is too low to capture the dust which is generated there# The conditions with respect to lead exposure existing at the plant during this visit are similar to those noted by Dr. ft# A.# Kehoe in a survey made i in A memorandum containing recommendations for improving K 0021680 Jc conditions was submitted by Dr* Kehoc on May 19 19*0# but apparently these roccmsEaendations have not been followed out to a sufficient extent to correct the conditions doscribed* ;-;ac orgmonot-t Io n a In view of the observations and air studios reported above, it is suggested that the recommendations inade by Dr* Kehoe in the meraoi'anduis of May 19, 19^-5 be followed as completely as possible* As suggested then, attention should be given to the use of adequate and well designed local exhaust ventilation, particularly at the points indicated below* 1* The unit shakeout should be locally ventilated ao that fumes are moved away from the breathing zone of the worker* itune should be exhausted both laterally and by downdraft* 2* The site of the core knockout operation should be ventilated in a manner similar to that recommended for the shakeout operation* 5* The ventilation of the gate cut-off machine should be improved by moving the exhaust opening closer to the cutting edge of the wheel, or preferably by using oowndr&ft ventilation at the adjustable table of the machine k* Downdraft local exhaust ventilation should be furnished to the stations on the large table where erc&ll castings are cleaned* K E 0021681 6 5 Air exhausted and laden v<ith lead compounds should be discharged In suoh manner as not to be a further source of contamination within the plant, and so us not to pollute the air ixi the vicinity of the plant* 6. inhere general room ventilation must be used, the air drawn in in winter should be pro-heated so that workers will not close doors ana vjlmiowa during extremely cold weather* The only alternative to the application of the foregoing measures at all of the sites indicated is that of the use of properly designed and maintained air line hose masks in connection with certain specified jobs of short duration* Since such jobs do not appear to fit into the picture of the plant operations, this alternative, which at best is a makeshift, Is not reg&z'cled. as feasible* From the Kettering Laboratory In the Department of Preventive Medicine and Industrial Health, College of Medicine University of Cincinnati, Cincinnati, Ohio Work by; J. Cholak, Ch*B* It. Burkey, 8*S* L. J* Schafer, B*S.S. <Ch*S.) Report toy* J. Cholak, Ch*E* Date : February 25, 1951 Approved* ______JT. Robert A* Kehoe, ,4*];' Director KET 0 0 2 1 6 8 2 Table 1 Conce nt rat ions of Lead I n the Atmosphere of the uudClea o f the Am erican Cr u cib le Product s Company a t Lo r a in , Ohio Analysis Number 51A-1G03 51A-1QG8 Location and Description In furnace room, fans on, doors and windows open (#1) In furnaoo room, fans on, doors and windows closed (6) Start II1O5 A.M. :1:20 -P,M, t Cu. Ft. Sampled 4*2 4*85 51A-1004 5U -1009 While skimming and stirring pot (7a Pb) fans on, windows and doors open (#2) Vihllo skimming and stirring pot {ll.lj- 15*5$ Pb) fans on, windows and doors closed (#7) 11:21 A.M. 1:35 1.02 1.52 0021683 51A-1005 While moving metal and casting at far (l * *$4 5 15 5end of foundry and return to furnace room Pb) fans on, windows and doors open (#3) 11:50 P.M. 51A-1006 51A-1G10 While moving metal and casting at far end of foundry and return to furnace room (lli.,5*155$ pb) fans on, windows arid doors open (with charcoal cover) (p4) 12:50 p .m . While moving metal and casting at far end of foundry and return to furnace room (ll*.5-15,5$ Pb) fans on, windows and aoors closed (#8) 1:1;5 p.a. k*9 4.85 7.05 ms i5l* rO*4 *J u uAAl O OuS y 1 . OS /*% zo* -*i-.;j- O -O3--s**rn-*3*4j.t. tTV o* *-4 *i ;>. * A* <* 4 rH 'V i\ K\ *0^ M H V*\A \ <M OfJA Os H O O oO if\ A H O O 3 3 A C> yM -\* * SW SU .r\ O r* 9 Mi ^4 A l -* o a* # -a? 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