Document 369gv3Q6g6VQekoy1vqE1nx

FILE NAME: Colgate (COL) DATE: 1977 Feb DOC#: COL036 DOCUMENT DESCRIPTION: National Safety News Article - Proceedings Define Qualities, Hazards of Asbestos Proceedings''Define Qualities, Hazards of Asbestos / THE Hazardous Materials Committee chairman of the Wood Products Sec tion, Lawrence S. Penkava, safety services manager, State AccidenfFnsiirarice Fund, State of Oregon, promoted the industry's first seminar in Portland, Ore., December 6, 1974. The seminar agem).? included: Asbestos and Wood Dust. Joseph D. Wendlick, corporate industrial hygienist, Weyerhaeuser Co. Wood Preservatives, Solvents and Flammables A1 Riegert, director, In dustrial Hygiene Department, Workers Compensation Board of British Colum bia. Carbon M onoxide Peter A Breysse, associate professor, Depart ment of Environmental Health, Uni versity of Washington. Formaldehyde and Caustics. Art Schoenborn, industrial hygienist, State Accident Insurance Fund, State of Oregon. Respirators and Protection Equip ment. Walter E. Ruch, regional pro gram director, NIOSH. In stru m en tatio n an'd C ontrols. Donald Quilici, industrial hygienist, OSHA. The proceedings will be published in several parts in order to give you a ready reference to some of the haz-' ardous materials in our industry. This m o n t h 's artic le w ill b e f r o m asb esto fi and wood dust proceedings. Asbestos What is asbestos? Asbestos is a member of a group of some 80 natu rally-occurring inorganic fibers, which is principally characterized by two broad mineral groups, the serpentines and the amphiboles. Only one signifi cant species of asbestos originates in the serpentine mineral group; chrysotile (a magnesium silicatB^ocCU'fflng as ~ long, white flexible, tubular fibers), the chief asbestos of commerce, mined principally in Canada, Italy, Rhodesia, and South Africa, as well as the USSR, Commercial deposits of asbestos also occur in the U.S in the states of Vermont, Arizona, and California. Amphiboles (iron silicates), on the other hand, include a number of as bestos species: amosite, crocidolite, anthophyllite, actinolite and tremolite which are mined in South Africa, Australia, Bolivia and Finland. What are the Standards? Prior to the Williams-Steiger Oc cupational Safety and Health Act of 1970, standards on asbestos were pri marily directed at minimizing workers' exposure to within limits thought to cause the debilitating disease, asbestosis, Consider, for example, the level adopted under the Walsh-IIealy Public Contracts Act of 1969, which set the acceptable limit at 12 fibers/cu cm This asbestos standard was in force until December 7, 1971 when OSHA published an emergency temporary standard concerning exposure to as bestos fibers which lowered the accept able airborne concentrations in the workplace to 5 fibers/cu cm greater than 5 microns in length for an 8-hour time-weighted average (TWA); and 10 fibers/cu cm greater than 5 microns in length for a ceiling concentration, effective July 7, 1972. NIOSH further recommended that the 5-fiber TWA and 10-fiber ceiling concentrations be permitted only for 2 years, thereafter, TWA concentrations should not-be mure^harr-2-ftbers/cttcm, with no change in the ceiling concentration. OSHA adopted this recommenda tion in the interest of the health of employees so exposed, such that after July 1, 1976, the acceptable airborne concentrations in the workplace will be 2 fihers/cu cm greater than 5 microns in length for an 8-hour TWA and 10 fibers/cu cm "greater than 5 microns in length for a ceiling concentration A specification on fiber size was included in the asbestos standards (greater than 5 microns m length) to denote those fibers possessing the greatest fibrogenic and carcinogenic potential. Fibers less than 5 microns in length, according to British studies, do not exhibit near the hazardous proper ties that mark -their "greater than 5 micron" counterparts; hence the inclu sion of a specific fiber size considera tion. What are the Hazards? The concern which precipitated the writing, adoption, and eventual pro mulgation, by OSHA, of the emergen cy temporary asbestos standard and later the permanent asbestos standard, CFR 1910.93a, was the evidence from several in v e s tig a to rs (no tab ly Dr. Irv ing Selikoff of the Mt. Sinai School of Medicine, N.Y.) which indicated a causal relationship between exposure to asbestos and the development of certain types of cancers after a latent (Continues on next page) u ;n D Wood Products Section Asbestos (Continuedfrom page l) (asymtomatic) period of 20-40 years Medical science has long been cog nizant that exposure to airborne as bestos fibers of high enough intensity and long enough duration will lead to a diffuse inorganic dust pneumoconiosis known as asbestosis. Asbestosis is an exposure-related disease which is characterized by in terstitial calcification and scarification, obliterating lung spaces, and replacing functional lung tissue with nonfunc tional collagen. It first manifests itself with either dyspnea (shortness of breath) or an irritating dry cough, over a period of many years. Progressively, as the condition advances, the worker will become increasingly shorter of breath (possibly cyanotic) with death -occurring-fmm respiratory failure nr heart failure. The more recent revelation, however, that asbestos exposures also increase the risk of: 1) gastric neoplasiz (esophagus, s'tomach, and small intes tine cancers); 2) bronchial carcinoma (principally among smokers); and fi nally, 3) a rare malignancy, meso thelioma of the pleura or peritoneum, has generated the most consternation. Because the attack rate of neoplasia among asbestos workers who smoke is 10-12 times higher than workers who do not smoke but are not exposed to asbestos, or who are exposed to as bestos but do not smoke, there would appear to be a synergistic cocarcinogenic effect involved in the de velopment of bronchial carcinoma. It was with regard for the carcinogenic effects of asbestos that the standard was lowered. WhalTmpdiiPi^cpnjaln asbestos? Long recognized as a substance possessing desirable fire-resistant char acteristics, asbestos fibers have found Editor: Joe Beckman Safety Director W eyerhaeuser Co Tacom a, Wash. 98401 The Information contained in this newsletter has been obtained from sources believed to be reliable, and the editors have exercised reasonable care to assure Its a ccu racy However, the National Safely Council does not guarantee that contents of this publication are correct, and statements attributed to other sources do not necessarily reflect the opinion or position of the Council use in a tremendously broad and diver sified array of products Some, but not all, of the product categories in which asbestos is used are given below. Asbestos-containing blown insula tion. Asbestos-reinforced magnesia or calcium silicate steam pipe covering and block insulation Brake shoes. Asbestos-containing grouts and ce ments. Clutch linings of cars Asbestos-cement products/bourd. Transite pipe. Asbestos-reinforced floor tiles. Asbestos cloth, blankets, clothing, gloves. Asbestos rope. Gasketing. Asbestos-containing taping for sheet rock joint work. FiWotrrtates; :--------- Filtering medium for wine, gin, etc Filtering medium for sulfate pre cipitates (Gooch crucibles) in analytical laboratories. Substitute Materials Available for Use ~ Because of the recognized hazards of working with asbestos-containing materials, especially friable asbestoscontaining products, many asbestosfree (but not fiber-free) products have been developed to lessen the asbestos hazard to workers and the general public Mineral wool fiber or fiber glass fiber-reinforced magnesia and calcium silicate pipe coverings and block insula tions are now available throughout the United States in all the shapes and sizes formerly available in asbestos-contain ing insulative materials. By example (not to be construed as product en dorsement), the following asbestosfree insulations are on the market: Pabco Super Cal Temp Type NA Johns-Manville Thermobestos (as bestos-free) Kaylo-10 (asbestos-free) Asbestos has been replaced in grouts and cements also, an example of which is Ryder One-Coat asbestos-free grouting. F o r p ro d u c ts with asbestos bound tightly in a rigid, nonfriable matrix such as with brake shoes, clutch linings, asbestos-cement board, most gasketing and asbestos-containing floor tiles, only a mechanical process such as cutting, sawing, drilling, or sanding would represent potentially hazardous National Safety Council work exposures All other handling activities could be performed with relative impunity Asbestos has been phased out of laboratory gravimetric analysis schemes in favor of turbidimetry, etc , and is no longer employed as a filtering medium for wine and gin (m this country). Nonfibrous talcs (no tremoltte asbestos) are available to replace the more potentially hazardous fibrous variety. Asbestos cloth, blankets, clothing, and gloves are now surfacetreated by the manufacturer to mini mize release of asbestos fibers to the workplace atmosphere It may well prove to be a false sense of security to assume that mineral woo), fiber glass or ceramic wool are "safe" vis-a-vis asbestos. As our tech nology improves in the development of better and better synthetic inorganic dfbersrand-as-frbers-appfoximatmg thesize and chemical composition of natu rally-occurring asbestos fibers are pro duced, these also may possess fibrogenic and even carcinogenic potential We would be well advised to exercise the same precautions m handling these products reinforced with mineral wool or fiber glass as in the case of asbestos. How are Levels o f-- --Exposure Determined? The accepted technique for evaluat ing or ascertaining level of exposure is to collect all of the fibers in a known amount of air by passing that air through a filter and subsequently, by microscopic counting methods, deter mining the numbers of actual fibers collected in the employees breathing zone in order that the fiber concentra tion can be related to the individual Once a determination has been made on the level of asbestos to which ar. employee is exposed, qualification fora medical surveillance program can also be evaluated According to the OSHA Sampling Method for Asbestos, the samples must be collected across the face of a Millipore Type AA cellulose acetate filter at a sampling rate of 2 liters/min. Duration of the sample will depend upon the relative concentrations of asbestos and extraneous matrix mate rial in the air at the time of sampling Attempting to conform rigidly to OSHA's recommended sampling time of 15 minutes minimum duration (in order to determine violations of the Safety Newsletter Wood Products Section ceiling exposure limit) may result in the loss of an important sample be cause the microscopist simply cannot get a reaiiable count on the heavily built-up fiber sample on the filter face Sampling in high visible dust areas should always be started at 2-4 min., then 5-7 min., 8-12 min. and finally 15 min to minimize loss of samples, particularly if the sampling site is several hundred miles from the count ing lab, or more importantly, if the samples taken are representative of an event not likely to be repeated on a planned schedule. Any industrial hygienists, environ mentalists, or analysts who are respon sible for the calibration of the person nel sampling pumps, collecting the samples in the workplace, and counting the fibers collected on the sampling filters should be aware of and take steps to mifHfrri-zfr the-errors which-can-- occur at various stages of sampling and analysis: 1. Altitude corrections. A pump calibrated at sea level and used at 4,000 ft above sea level may be off in the actual volume by 5 percent. 2. Cassette orientation. A sampling cassette resting against a worker's uni form or clothing at the lapel will have a different fiber distribution across the fiber face than one located in the breathing zone but away from the uniform 3. Ester mixture. The ester mixture used to dissolve away the filter in the counting procedure should be of a consistent concentration and saturated with filter so as to minimize errors in masking fibers with a liquid of similar refractive Index. 4. Counting. Counts run on wedges cut from the same filter may vary by as much as plus or minus 30-40 riercent 5. Microscope. Although rnany mi croscopes can meet thajcequirement of phase contrast illum ination at 400-450X magnification, microscope resolution varies considerably from brand to brand. 6. Eye. Problems of resolution are not just limited to the microscope. The eyes of different " counters" can also vary. To minimize this error, the same individual (s) should always make the counts. All of these errors can total (by compounding) plus or minus 40-50 percent, which means that in order for an inspector to cite a violation of the TWA portion of the present asbestos standard and have it stand up in court, the TWA should be at least 7.0-7.5 fibers/cm*123456greater than 5 microns in length. For the ceiling limit, the values would have to be 14-15 fibers/cm3 greater than 5 microns in length for, by definition, a 15-minute sample. Con versely, in order for an employer to demonstrate compliance with these limits, typical workplace environmental levels would have to be 2.5-3.0 fibers/ cm3 respectively. __Asbestos, C ontrol Methods Various methods of control have been applied successfully to handling or working with asbestos products to either minimize or eliminate worker asbestos exposure in the workplace. These include, but are not limited to: -- l-.~Wet- methods,--Wetting down asbestos-reinforced insulations prior to demolition or rip-out and, to some extent, reapplication will reduce air borne asbestos levels in the breathing zone of affected workers by 80-85 percent, according to a 1970 publica tion entitled Asbestos Exposure and Control at Puget Sound Naval Shipyard by Mangold, Beckett, and Bessmer The new proposed regulations on asbestos by the Environmental Protec tion Agency for building demolition and renovation stipulate wet-down practices as the asbestos control meth od of choice (the only exclusion being contractors who renovate ur demolish buildings in subfreezing temperatures). Unfortunately, alternatives are not permitted, as the proposed regulations now read, to minimize damage to electrical equipment or to other water'sensitive equipment, 2. Substitution. Asbestos fiber sub stitutes (e.g., mineral wool, ceramic wool, and fiber glass), both alone, in mats or fluff, or as'reinforcing fibers in friable magnesia or calcium silicate insulations can be used. Use of nonfibrous talcs",- etc:--represents--other materials which, in most cases, will suffice. To reiterate, however, these syn thetic inorganic fiber substitutes may (Continues on next page) NIOSH Awards Research Contract THE Stanford Research Institute, Menlo Park, Calif., has been awarded a 22-month research con tract by the National Institute for Occupational Safety and Health (NIOSH). The purpose of this study is to examine the mortality experi ence of individuals who were em ployed in the Northwest plywood, pulp, and paper industries for at least 12 months between 1946 and 1960, In particular, the contractor will assess if these employees experi enced an excess mortality due to malignant disease. Where available, mill employment records will be analyzed, along with other sources of information. Association, compa ny, union, NIOSH, and Stanford Research Institute representatives met in Cincinnati, Ohio to discuss research procedures. Dr. Bobby F. Craft, division director of NIOSH, advised that NIOSH has a $50 million budget and 850 people for programs and project plans. The Northwest Plywood, Pulp, and Paper Mortality Study is one of 50 projects admin istered by the NIOSH Cincinnati office, which has a staff of 150. Dr Craft indicated that Leo Sanders is the contracting officer for the Northwest Study Cynthia Robinson, NIOSH epi demiologist, and Dr. William Gaffey, contractor with SRI, re viewed the NIOSH study protocol Robinson reported that the study will include collecting personnel in formation from mill records and characterizing a mill environment by industrial hygiene survey. Dr. Gaffey reported that the cohort size would be 5,000, rather than 20,000 people as specified in the original study. Dr, Craft further indicated that the tripartite group would re ceive quarterly progress reports and that a meeting of this group would be held to review the study results prior to release. It's scheduled to take about two years to complete under a $135,000 NIOSH contract, a Wood Products Section Newsletter Asbestos (Continuedfrom page 3) have the same potential for inducing exposure-related disease as with as bestos. 3. Ventilation Two types of ventila tion are usually available for control of occupational health hazards: a) general ventialtion, and b) local exhaust ven tilation. Because of the potentially grave consequences of exposure and all the unknowns as to the precise level of asbestos fibers in the air which is safe to breathe without developing a meso thelioma 20-40 years later, general ventialtion in the control of asbestos is not an' acceptable control method (within technical reason and econom ical feasibility). Local exhaust vential tion, on the other hand, is an excellent control method for capturing asbestos fibers at the point of origin. For high velocity mechanical opera tions on asbestos-containing products (drilling, sawing, and routing), the high velocity/low volume concept of dust control (as advocated by Hoffman Dust Control Systems) offers the best means, both economically and techanically, for controlling the dust emis sions from the power tool. In all cases where a local exhaust ventialtion sys tem is used for control of asbestoscontaining dusts, a baghouse should be included in the system. Cyclones, even high efficiency cyclones in series, are not efficient enough to control the emissions to the "no visible emis sions" requirement of the EPA stan dard. 4. Handling practices. While this may seem so insignificant as not to warrant mention, employees handling asbestos-containing materials (es pecially dry) in a proper manner can reduce their exposures sufficiently by this route, in conjunction with other engineering controls, to comply with the OSHA standard. 5. Isolation. Control by isolation or enclosure is another way of minimizing or eliminating employee asbestos ex posures in the workplace. This method has proven effective in control of carcinogen exposures and radiation (ionizing) exposure. --Joseph D. Wendlick Corporate Industrial Hygienist Weyerhaeuser Co. Wood Dust, will be published next month. Most Accidents Result from Commonplace Situations ANYONE undertaking a review of the investigation reports received this year could not help but note two striking situations: 1. The injuries we have sustained have not been the by-products of major or disastrous events. The disabling injuries we have had, as serious as some of them have been, have not been associated with such potentially disastrous situations as runaway reac tions, vessel ruptures, large volume vapor emissions, flammable liquid spills, or large scale process failures. 2. The accidents we have had that have accounted for our injuries have been the by-products of pedestriairr everyday kinds of malfunctions and malpractices. As personally severe as many of the injuries have been, they have not been the product of unusual, unpredictable, or exceptional events. They have been the by-products of situations such as' failure to apply an established procedure. improvising because of an inade quate design. getting caught in moving equip ment. shortcutting lockout procedures. employing a questionable practice because a safer alternative had not been established. Stated in the cold, seemingly harsh and impersonal language of analysis, the second striking fact about the accidents we are having is that they are commonplace accidents. They are the products of ordinary, nonexceptional situations. It is not the tigers that have been troubling us: the high pressure pro cesses, the tremendous quantities of flammables, and the massive opera tions. These have not been the source of our disabling injuries Our high hazard installations, materials, and jobs are recognized as extremely hazardous. Therefore we know what is required to keep them in control and we take that extra effort to control them. We control them because they are obvious and because there is an awareness of the disastrous results should we fail. There is good news in this fact There is also good news m the fact that the accidents we are having are the consequences of commonplace condi tions and commonplace conduct Acci dents that are the product of common failures, common neglect, and com mon events are more controllable. Therefore, they should be easier to correct. There is unfortunate news m this fact, as well. It is our familiarity with material and jobs that makes us tend to neglect them. It is the minor task, the daily operation, and the repetitive performarrartbat we neglect---------------- the sampling job we do four times each day the drums we open the vehicles we operate the hand tools we use the floors we walk over the stairs we descend. These conditions, these little " or dinary dogs" , the ones that are the easiest to defend ourselves against, are the ones that jump up and bite us We are aware of the tigers The tigers are caged, but the dogs still run loose. Accident information Monsanto Co. Safety Newsletter 4L e s s o n s Le a rn e d *45