Document jNjbL552YOXdGN22a4o0Y3mKy

FILE NAME: Hercules Chemical (HERC) DATE: 1966 July 19 DOC#: HERC023 DOCUMENT DESCRIPTION: Consultant Report - A Study of the Asbestos Hazard, Haveg Industries Inc. STUDY OF THE ASBESTOS HAZARD HAVEG IMDUSTKIES * INCORPORATED Wilmington, Delaware January 19 3-9^6 industrial Hygiene Services Employers Mutuals of Wausau fan*/ Exhibit 30 A STUDY 0? THE ASESSTOS HAZARD HAVEG INDUSTRIES . -. . INCORPORATED Wilmington, Delaware ' . By . J. Uber (l) and G. B. Fletcher (2) This study was made on January 19, 1966, to determine the concentration of asbestos dust to which workers are exposed during normal operations, and to evaluate the need for controls to prevent excessive exposures. Scope of Study Five atmospheric dust samples were collected In the Asbestos Treating, Drying, Storage, and Mixing Rooms. - Apparatus and Method of Analysis The samples for atmospheric dust were collected by means of the M. S. A. Midget Impinger. The impinger flask was placed in the breathing zone of the workers involved, and the sample collected. Following collection, the sample flasks were submitted to the labora tory and dust counts made using the Sedgewick-Rafter counting cells and a microscope calibrated for mounting dust according to the United States Public Health Service Standard Mathod. Threshold limit Valua For Asbestos ' The' American Conference of Governmental Industrial Hygienists has adopted a Threshold Limit-Value (TLV) of 5,000,000 particles"'per cubic " - foot of air (m. p. p. c. f.). ' The TLV for asbestos, as for othe_r dusts, fumes, vapors aruLgases*- represents the concentration to which workers nay be exposed, 8 hours par day, 5 days per week indefinitely without adverse effects upon their health. These concentrations refer to the average 8 hour exposures, rather than to maximum values which should not be exceeded even momentar ily. . . Analytical Results The dust counts as determined by the light-field technique, are given in-Table. I, together with the TLV. - - - (1) Industrial Hygiene Consultant, Employers Insurance of Wausau, New York, N. Y. (2) Safety Consultant, Employers Insurance of Wausau, Norfolk, Virginia Sample Number 1 2 3 V 5 . TABLE I CONCENTRATIONS OP ASBESTOS XK AIR HAVEG INDUSTRIES INCORPORATED ____' January 19, 196g______ Location Dust Concentra-fcion in Air.m.-n.r .s.f. fround TLV Remarks Asbestos Drying Department 7 .1 5.0 Asbestos Storage Department 20.0 5-0 A B Asbestos Drying Department 18 A 5.0 C Asbestos Mixing Department Location Asbestos Treating Department -- 17.3 0.8 5.0 D 5-0 - E Renarks : ____ '* A. One man, no respirator. Inspection door on the chute from the dryer to the pneumatic conveyor open. Settled dust accumulations on horizontal structures. ' B. No Bins unloaded during sample, hut dust escaping bins into the . ____ work area through cracks and other openings in the bins. Bin '" ` ~ exhaust fan operating backwards. ' _ C. Repeat of sample No. 1, after bin exhaust fan rotation ,,^direction was corrected. ' - ~- " D. . One man,- no respiratoj-_.__Two carts were loaded from Bin No. 3 ' during sampling. Direction of air flow was from the Storage , Department to the Mixing Department. ' ' E. Work in this department is wet work. - 3- Discussion of Results ' ^ Only in the Treating Department were the lust concentrations below '"S ThrSChld TalUa' Ia "hor * Asbestos l0 handled ' . dust concentrations range! f t * 7 .1 ffip?cf (Saaple ^ ^ 2Q<Q (Sample Ko. a). ` . - . '*" * ^ W M . il tta a w * " * a m i to o s Into tte a m , t t m m , a . a m . u . Storage Department. "During the survev ,*,,=. , . ^ xng e survey, dus,, clouds were observed escaping j.roa the bins desuite the ouera-Hnn ,,p +1, , , - e operation of the exhaust fan designed to ventil ate the bins. Ele M e h a5'aSt0S dUSt n a t i o n found in the Mixing Department (17.3 p c f ), where local exhaust ventilation hoods axe located at each nixer, is attributable to the a o v e U t of dusty air from the Storage area - t o the_Kixing Department with aTair inflow to the bins, rather than an outflow such-as existed during the survey, both the Storage aid Mixing areas would have considerably lower dust concentrations. " ' Suggestions For Improved Controls The following suggestions are offered for reducing the asbestos dust exposure: ' . H A H leaks from the dryer and pneumatic conveying system should he eliminated to prevent the escape of dust into the dryer area. - 2. The inspection door on the chute from the dryer to the pneumatic conveyor should te kept closed to conserve exhaust ventilation capacity. 3 The storage bins should be placed under negative pressure so that air flow would be into the "bins even with a door opened for cart loading. This would require the exhaust fan on the bins to have a-capacity of 100 cubic feet of air per minute per square foot of door opening, in addition to the ____ capacity of the pneumatic conveying system. ' 1*-. The bin exhaust fan should be provided with an air flow switch -- interlocked with the dryer or with an alarm, so that low air - flows through the exhaust system would either shut down the dryer or sound the alarm indicating the need for corrective measures. 1 ' Until dust control measures can be instituted, workers in the Storage, Drying.and_Mixing areas should wear U.- SI--Bureau of . Klnes approved dust respirators of the type presently used when bins are unloaded. 6. A measure of the effectiveness of dust control measures'is'lhe periodic physical.examination program presently in effect. Eiis program, which includes chest x-rays of workers exposed to asbestos should be continued. Conclusion ' Elis study showed that operations involving asbestos in the Drying, Storage, and Mixing Departments results in excessive air-borne dust con c e n t r a t i o n s S o m a suggestions have been given for minimizing the exposure of workers to excessive concentrations of asbestos dust.