Document 6krVDgXLobRbppNk56VnmjB1

Babcock & Wilcox a McDermott company Insulating Products Division P. O. Box 923 Augusta. Georgia 30903 (404) 796-4200 June 7, 1985 Dear Kaowoo! Customer: We are attaching a copy of our booklet entitled "Health and Safety Aspects of Refractory Ceramic Fibers." This covers the test work done over the past years as well as the current work being conducted. Right now we know of no knowrr chronic health effects in humans from long-term exposure to refractory fibers. We are a member of the "Thermal Insulation Manufacturers Association" (TIMA) who have designed and are funding new studies relating to animals and to people. Results from these studies will not be available for another 3 to 5 years. The booklet reports on two known investigations recently conducted which have studied the effects of refractory ceramic fibers, but these were only on animals. The results are outlined and while the results differ in many ways, there is little doubt that a higher level of caution now exists about the possible health implications of exposure to ceramic fiber. We will keep you advised of any further developments. In the meantime, we recommend that refractory ceramic fiber products be handled in accordance with thelprocedures outlined in the attached booklet. If you have any questions or fried any additional information, please contact Mr. Miguel Pereyo, Manager of Operations (404-796-4254), or Mr. James Fernstrom, Busines^Manager, Ceramic Fiber ( 404-796-4310). Sincerely Manager Marketina and Sales 015750 efractory ceramic fibers' are"amorphous, giassy, mina silica products .which are created from . ylten masses of synthetic raw materials or aturally occurring kaolin "clays. The family of fibers anufactured by.Babcock & Wiicox is marketed ider the trade names nf Kanwoo|LUnifsit Ultrafelt.' 3 Kaowool, Kaolana," Fibralana, Saber Bloc, Pyro-' toe, Uni-Bloc, and Pyro-Log. efractory ceramic'fibers (RCF) have been produc1 in commercial quantities for approximately 25 to ) years. Due to its relatively short history, we feel . at it is necessary to establish through testing nether or not the health effects of these fibers are entical to those reported for glass and rockwool . >ers. The RCF industry, through the auspices of e Thermal Insulation Manufacturers Association . IMA), is sponsoring animat inhalation studies as ell as epidemiological studies of workers in the inistrv. Until such time as definite answers are"" . ' ailable, it is advisable to follow common sense ark practices designed to minimize exposure to ese refractory ceramic.fibers.. ecommended Handling Procedures icupationai Exposure Guidelines. fractory ceramic fibers (RCF) are not currently gulated in the occupational environment by any , ieral or state health agency. Babcock & Wilcox s established a work place exposure guideline of fibers/cubic centimeter as a result of the ,-dicat and scientific findings available at this time, e work place exposure guideline refers to an airrne concentration of a substance, time weighted a 7 to 8-hour workday and a 40-hour workweek, tier which is believed that nearly alt workers may repeatedly exposed day after day without /erse health effects. No employee.should work hout protective equipment in environments where airborne concentrations exceed-10 fibers per tic centimeter even for short periods of time. ustrial sampling data obtained at Babcock & cox manufacturing locations where refractory amic fiber products are manufactured show that josures are below the work place exposure deline of 2 fibers per cubic centimeter. ield installations where confined areas have poor dilation, it" may be possible to exceed the work ce exposure guideline of 2 fibers per cubic centiter. In such situations, temporary exhaust ventilai should be installed. If this is not feasible, the of respiratory protection and specified work ctices must be required as detailed in this :ument. Refractory ceramic fibers pose an additional health concern after the product has been inserYic8.'-::V> Crystalline silica In the form of cristobalite Is formed. CristoDalite exposures may cause lung disease (silicosis) if overexposure occurs. The Occupational' Safety and Health Organization (OSHA), United States Department of Labor regulates exposure to cristobalite under 29 CFR 1910.1000, Table 2-3, . Mineral Dusts. Recommended Work Practices The procedures recommended in the following sec tion are good practices that apply when working where all types of dust can be generated. Loom Clothing. Wearing long-sleeved shirts and blouses, loose at the neck and wrists, along with long pants and caps will protect skin areas from coming in contact with refractory ceramic fiber. Loose clothing also helps prevent fiber from rubbing into the skin. Depending on job conditions, gloves may be necessary. . . .... . Minimizing Dust. Mechanical dust collection sys tems should be used whenever refractory ceramic fiber materials are machine sawed or sanded. Handling and cutting should be done in a manner that will create the least amount of airborne dust. Skin Irritation. If refractory ceramic fiber particles accumulate on exposed skin areas, do-not rub or scratch._flemove the particles by washing the skin thoroughly but gently with warm water and mild soap. Using a good commercial skin cream or lotion after washing may be helpful. - Eye .Protection. Safety glasses, goggles, or face shields should be worn whenever refractory ceramic fiber materials are being applied overhead or in areas'where loose particles may get into the eyes. Respirators. Respiratory protection must be worn to protect against breathing air contaminated with potentially harmful materials such as refractory ceramic fiber and cristobalite. Acceptable respirators are those approved by NIOSH for usage-in specific airborne concentrations. -3- Chevron BB 015751 Refractory Ceramic Fiber Exposure Respirators Concentrattoo 2.0 - 5.0 f/cc 5.0 - 50.0 f/cc 50.0 f/CC Respirator 2M 9900, or 3M 8710 equivalent. Survivair full face piecUSvith high efficiency filter 1090-00 or equivalent. MSA 01-00-06 full face piece type C suppiied-air or equiva lent OSHA approved air^ source required. Cristobailte Exposure Respirators Concentration up to 10 times PEL* 10 to 100 times PEL* 100 times PEL* Respirator 3M 9900, or 3M 8710 equivalent. Survivair full face piece vsnth high efficiency filter 1090310 or equivalent. MSA 01-00-06 full face piece type C supplied-air or equtva7 lent. OSHA approved air source required. Respirator users should be instructed as to the proper use of respirators and their limitations, and musTbe fit-tested to assess the quality of fit. To test thelres- pirator, cover the air inlets with the palm of theE hand, inhale so the facepiece collapses slightlyT then hold breath for a few seconds to see thaQL re mains collapsed and there are -no leaks. Another, method is to place a substance with distinct odor or taste near the respirator seal. It should be undetec - table if the respirator fits well. _ 'Disposable respirators should be discarded whenT- soiled or when breathing resistance is noticedlB^ the wearer. Non-disposables must be regularly 1"; cleaned, inspected and maintained. fee.. A wearer of respiratory protection experiencing^ breathing difficulty while using respirators should be evaluated by a physician to determine the abilitylof the worker to wear a respirator. -s Personal Protective Equipment. In work situa tions in which engineering controls and/or localex- haust ventilation are either technically not feasible or insufficient to reduce the airborne concentrations -of refractory ceramic fibers to below a time 'EE weighted average of 2 f/cc. the following clothirtg; ~ guidelines are recommended: iff' 1. Special clothing. Provide and require the use of special clothing, such as coveralls or similar wfEJebody clothing, head coverings, gloves, and foot cgflrerings for any employee exposed to airborne concen trations of refractory ceramic fibers which excels a -4- ceiling of 10 f/cc. Provide changing rooms for employees working regularly in such arTehvironmeht. 2. Clothes lockers. Provide two separate lockers.. or containers for each employee, so separated or isolated as to prevent contamination of the employee's street clothes from work clothes. 3. Laundering. Laundering of clothing contami nated with refractory ceramic fibers shall be done so as to prevent the release of airborne fibers in excess of the 2.0 f/cc WEG. Housekeeping. Avoid unnecessary rehandling of scrap materials by keeping waste disposal equipment as close to working areas as possible. Follow an organized housekeeping program at all times. Vacuum dust with equipment fitted with HEPA filter. If sweeping is necessary, use a dust suppressant. * Waste Managemont. Wastes generated during ap plication, demolition, breakage or spillage are not hazardous wastes as defined by RCRA (40 CFR Part 261). Comply with federal, state and local regulations. Method of disposal landfill. RQ - N/A. Skin irritation Refractory ceramic fiber and most glass fibers are very similar in their ability to cause skin and uooer respiratory irritation. SKIN IRRITATION is experienced by some workers in refractory fiber manufacturing facilities as well as some people working with re fractory fiber-containing materials.This skin irritation and possible inflammation is a mechanical reaction due to sharp, broken ends of fiber that rub or become embedded in the outer layer of the skin. Skin reactions vary directly with the size and the stiffness of the fiber handled, with fibers of large diameter being more likely to cause irritation a.nc it ching. Irritation normally does not per sist for any length of time and can be relieved by washing exposed skin areas gently in warm water with mild soap. "Some individuals may be more sensitive to irritation from refractory ceramic fibers than are others, and a relatively small number may be forced to seek other types of employment. The vast majority of workers, ` however, can control.skinlrritation by following work - practices outlined in this bulletin. Upper Respiratory Irritation It is possible that some workers may experience temporary UPPER RESPIRATORY IRRITATION (that is. scratchiness or burning of the nose or throat) if airborne refractory fibers are generated during manu facture or handling of refractory fiber-containing -5- Chevron BB 015752 products. Lite skin irritation, upper respiratory iTnta-. tion is a mechanical reaction to sharp, broken ~ . fibers. It is not an allergic reaction and the irritation does not persist. ; '7l Unprotected exposures to high concentrations of air- , - borne refractory ceramic fiber may produce a transi- .. tory condition, usually manifested by coughing or _ wheezing. Careful attention to housekeeping ancT' proper work practices can effectively control air- r borne refractory ceramic fiber concentrations t(T~ prevent this upper respiratory irritation. The effects subside soon after the worker is removed from es? posure and have no known long-lasting impact off . health. t- . After Service Refractory ceramic fiber which has been in service at elevated temperatures (greater than 1000Cf rhav jinrtnrnn partial conversion to cnstobalite, a torm_ot* crystalline silica wmcn can cause respiratory disease fsiiicosisf. This is a consequence of the crystalliza tion or devitrification of the fibers which occurs at high temperatures. The amount of cristobalite whjgh is formed, the size of the individual crystallites and the nature of the matrix in which they are embedd ed are all a function of the temperature and the^= length of time the fiber has been heated. Under normal use conditions, refractory ceramics fiber will generally be exposed to a temperaturejjradient. Consequently it is most probable that only the fiber nearest the hot surface will have an apprectP ble cristobalite .content. It is-also possible that the! devitrified cristobalite-containing fiber will be moogl friable and therefore may generate a larger amogpi of dust when fiber is removed from a high temperature application. Experiments have not yeTT been conducted to ascertain whether or not thes^ devitrified fibers are biologically active in animals. . For these reasons particular care should be takerr" during the ;iear-out" of. refractory ceramic fiber firPj mgs to minimize generation of "dust. Adherence to^ proper methods of dust suppression and control ifF imperative. The most prudent approach is to treat devitrified fibers as free crystalline silica. Even wUfT adequate control, Babcock & Wilcox recommends;! that a respirator approved by NIOSH be used by aF workers in the area during removal operations. ss. Medical and Scientific Studies There are no known published reports in medical^ literature dealing with the health experience of peST pie who work with refractory ceramic fibers. Two studies, one in Europe and the other in the United^ States, are in the initial planning stages to study tlie -6- & health of workers involved in the manufacturing of refractory ceramic fibers. Initial results from those ' studies will be available'm three to five years. There are two known Investigations which have studied the effects of refractory ceramic fibers on animals. An investigation by Davis, et al, in Edin burgh has been completed and published'. The other study is nearing completion at the Los Alamos National Laboratories? and should be available for publication witin the next year. Summaries of the results of the Davis Study and an interim report of the Los Alamos study will be covered below. In his experiments. Davis injected refractory ceramic fibers into the abdomens of 32 rats. Intraperitoneal injection of fiber bypasses ail of the animals' natural defenses and is used in an in dicator of the relative biological activity of fibrous materials, although it does not duplicate any type of human exposure. In this experiment, three of the 32 animals developed primary abdominal tumors. Depending on the dose, scientists have found some tumor formation when injecting virtually all types of fibers directly into the abdomen. Such results from intraperitoneai injections have been found no matter what the experience has been in inhalation experiments. Davis also exposed forty-eight rats to refractory ceramic fiber by inhalation for seven hours a day, five days a week, over a period of 224 -days. The airborne dose of fibers longer than 5 microns was reported to be 95 fibers/cc. Animals sacrificed at the end of . the study were reported to have an average of 5% pulmonary fibrosis. At the end of the study, eight of the rats were found to have tumors with three animals demonstrating carcinomas. The fibrosis and carcinoma found in the Davis stucy by inhalation were not expected and clearly point to the need, for further study, while raising the normal level of concern. In -1979, a large scale animal exposure experiment was begun al the Los Alamos National Laboratories involving several types of man-made fibers, in cluding refractory ceramic fiber. In the Los Alamos study,, two animal models were used -- rats and hamsters. The~rats were of a different strain than the ones used in the Davis study mentioned above. . The Los Alamos study is not yet complete; results to date concerning refractory ceramic fiber will be summarized here and updated when the study is completed. To date, inhalation experiments involving rats show no cancer or fibrosis in twenty-live animaTs' examin ed; this conflicts sharpiv thus tar with the Davis -7- Chevron BB 015753 A il -.V -tf.p'V. .. . v. *4: r study. Inhalation experiments on hamsters showed vV.< ..., ,, : one cancer (mesothelioma) in fifty animals, but no .- Tibrogis was-nhserved. One ot 157 control animaTTi-",'.'-TT.C. developed a spontaneous'tumor ^thaijLgxposUre" F fibers. The exposures were conducted at. 200 VccrB:^}F<) hours a day, _5 days a week, for 24 v The researchers at Los Alamos also performed In-.'rV '; traperitonealjnjections of refractory ceramic fiber' " '-l'.- using both hamsters and rats. Most of the hamsters .-..V, ' did not tolerate the initial injection of the .fiber info" *3'h.;.~Tr their abdomens and died immediately'aher. injection ^""5,' - due to peritoneal hemorrhaging. Of the five animals - " ' . so far reported who survived the Injection, no -'.. tumors were found. Nineteen of the twenty-two rats examined developed tumors (primarily mesothelio- ; mas) after Intraperitoneal Injection of refractory .. *' ceramic fiber.This result was very different .from'-':; fi: -V: the results obtained by Davis.'-^-v ; . While the results from the Davis and Los' Alamos -' -:. .studies were .conflicting in many-ways, there is little doubt a higher level of caution now exists about the -V: ` possible healthlmplications of exposure to refrac* f'4. tory ceramic fiber. In order to'help clarify some of.;.!'* " the uncertainty raised, new studies have been ' designed and funded by TIMA to study the human experience asT_wel! as further animal studies with - refractory ceramic fibers. This effort will begin in " - - - late 1985 and begin producing results in three to ' five years. Unfit more is known about the possible . ' health effects of refractory ceramic fiber, care _' should be taken,when using these products as detailed in this55ocument. ..' - : j [' j.` K ! ; i "Footnote* - .. -:'l - 1. J.M.G. DaviSTJ. Addison. R.E. Bolton, K . i.. . - Donaldson, A.D. Jones & A. Wright, "The I -< ' Pathogenic Effects of Fibrous Ceramic Aluminum ' ; - " Silicate Glass Administered to Rats by Inhalation or ' .' 1 Peritoneal Injection;' Biological Effects of Man-made '" " > . Mineral Fibres, Vol. 2, p.303. v- v 2. D.M. SmithrPrincipal Investigator; Interim - . ; Progress Report To Medical Scientific Committee of I TIMA. . . : j REF. 05/85 10 M" . - 'r [ Babcock & Wilcox, | Insulating Products Division, i P. o. Box 923, I Augusta, Georgia 30903. I 404 796-4200 a McDermott company i 8- - Chevron BB 015754