Document pd2KmKdxEDbMr7GOGjBgBv0j

FILE NAME: Reynolds Metals (RM) DATE: 1963 DOC#: RM001 DOCUMENT DESCRIPTION: Industrial Hygiene Bulletin r ______ V tttiw 'H ii ^ u a r a * i^ 4 < iu tn w r c ::>: ir* * i .** -- *1 '* . * . ' IN D U ST R IA L H Y G IE N E /e*aL- i f f * BULLETIN j No. j j Asbestos ; PLAINTIFFS i EXHIBIT I RM C-35 S ign ifican t Properties A ch aracteristica lly silk y, fibrous mineral. Breaks into f i l a ments or fibers readily. Chemical Formula: 3 MgO 2 SiO^ * 2 H2O (for chrysotile, the mineral in 95 per cent of commercial asbestos}. Calciua-magnes: s i li c a t e and Iron Magnesium silic a te are also found in nature a: are also called asbestos. Flash point: Does not burn. Solubility;: V irtually insoluble in water and body flu id s. Uses Asbestos is used alone or mixed with cement-like substances for insulation, fir e proofing and other -construction purposes; mixe< with cotton or other te x tile fib ers, i t is woven into fir e resi; fcant cloth. In MARINITE, asbestos is incorporated in amounts that vary between 25 and 50 per cent and, since i t is widely us> in handling molten aluminum, this material probably constitutes the largest potential source of asbestos dust in RMC plants. Advice from the manufacturer states that MARINITE dust should b< treated as.though, i t were entirely asbestos dust. Hygienic Standards Recommended maximum for asbestos dust in air (8 hours): $ m illi* p a rticle s per cubic foot (MPPCF). Health Hazards Acute. None. The unlikelihood of the asbestos dissolving in w; or tissue flu id s makes any toxic reaction very remote. Chronic. Inhaling asbestos dust can cause particles to be trap; in- the lungs and retained there. Long continued Inhalation of large amounts of this dust results in lung changes (pneumoeonlo and the name, asbestosis, has been applied to these changes. I. exposure to excessive asbestos dust is allowed to continue long enough, injury w ill resu lt. These lung changes resemble s ilic o in that they are not disabling in the early stages. When allow, to develop unchecked asbestosis can become disabling. Ten to twenty years of daily exposure are probably needed to induce serious lung changes. The onset of symptoms, in asbestosis, as. in s ilic o s is , is slow b' in advanced stages symptoms arB lik e ly to be somewhat more seve: than in s ilic o s is . Dyspnea is a cardinal symptom. Lack of app bite occurs in advanced asbestosis, and cyanosis (with related symptoms) are seen more frequently than in s ilic o s is . 000008 The fib r o s is caused by inhaling asbestosis is d iffu se and tends to be most prominent in the basal portions of the lungs in con t r a s t to the more generalized d istrib u tio n of nodular fib r o s is induced by s i l i c a . Asbestos is believed to have a mechanical rather than chemical action and fib er s in the range of 20 to $ 0 microns are the most hazardous to the lungs. Experiments in v o lv in g dust containing only fib er s ground to le ss than 20 microns fa ile d to induce asbestosis in animals. The prognosis in early or moderately advanced asbestosis i s good provided the inhalation of asbestos dust is discontinued or pro vided the dustiness is very g re a tly reduced. Unlike s i l i c o s i s , asb esto sis does not tend to progress a fter exposture has been adequately decreased. In very advanced stages, asbestosis CDnrao) l y involves considerable emphysema and frequently progresses to r ig h t heari stra in and fa ilu r e . Tuberculosis has not been found with, any unusual frequency among cases of asb esto sis. However, cancer has been alleged (mostly ii Europe) in connection with asbestosis, This remains unproven. In d u stria l Hygiene Practice Prevention of asbestosis depends e n tir e ly in controlling the dus^ containing asbestos (MARHIITE). Enclosure of dusty operations oi the use of lo c a l exhaust ven tila tio n are the best means of main ta in in g the amount of dust at or below the safe le v e l of j? MPPCF. Dust respirators approved by the U.S. Bureau of Mines should be worn where exhaust v en tila tio n cannot be in sta lled for co n tro llii asbestos dust. Airborne asbestos dust can be sampled ( l) with an e le c tr o s ta tic p r e c ip ita to r or (2) by aspirating a ir through water in impinger f la s k s , and dust counts made by the lig h t f ie ld technique. Medical Procedures F ir s t Aid. None required. Surveillance. (1 ) Preplacement examination, including chest x-rays, should be used to avoid placing a workman with lung abnormalities in a p o te n tia lly dusty job. (2 ) Periodic re-examinations should be made of persons who work in dusty areas. (3) Treatment. Other than early removal from exposure no s a tis fa c to ry treatment for asbestosis has been found. September 1963 I n d u s tr ia l Hygiene Department 000009