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ai it of hi m ht st< m. i ?0 APRIL 1985 AU439h b'j an> and hot water pipes, and applying it in a cement form to the outside of boilers. Most older buildings which have not been substantially re modeled during the past 20 years have asbestos wrapped around steam or hot water pipes as ther mal insulation. This type of wrap ping is called pipe lagging. The building may also have a furnace which has been insulated with asbestos wrap for thermal rea sons, and the structural beams and ceilings may have been sprayed with asbestos for fire proofing. Each of these uses of asbestos is an application where the material can degrade and re lease a substantial quantity of as bestos fibers into the environ ment. There are other uses of asbestos such as in automobile brake lin ings, heat protecting clothing, vi nyl asbestos floor tile or ceiling tiles, asbestos siding or roofing tiles and solid asbestos sheets placed behind a fireplace, which are not as potentially harmful to the public. Hew to determine Hie risk associated wftfi asbestos Most of the health hazards as sociated with asbestos are pulmo nary or lung diseases. Therefore, for asbestos to be hazardous it has to be in a form which can be breathed. When asbestos insula tion products are manufactured, the asbestos is "fluffed up" into a fibrous form and then mixed with (continued) *>y DOROTHY L. STANSEL, MA,, C.I.H. The top photo shows a pump with filter lor sampling air to determine possible asbestos contamination. Bottom photo depicts badly damaged pipes and beams -- note that damaged asbestos is scattered over the floor. AU439ii Dorothy L. Stansel hasaB. A. degree in Chemistry from Oberlin College and a M. A. degree, also in Chemistry, from the State University ofNew York at Binghamton. Since 1976, she has been an Industrial Hygiene Consultant with the Depart ment of Environmental Health in the School of Public Health and Community Medicine at the University of Washington in Seattle. One of the projects Stansel has worked on is the industrial hygiene monitoring during the asbestos removal from 24 Seat tle Public Schools. Most recently she has written the scope of work specifications for asbestos abatement at Seattle-Tacoma International Airport, and has been a consultant to the FAA during an asbestos removal project at their Air Route Traffic Control Center in Auburn. HA. Stansel is fully certified in the comprehensive practice of in dustrial hygiene by the Amer ican Board of Industrial Hygiene. BUILDING OPERATING MANAGEMENT 91 ASBESTOS `Friable' is a term used for badly-damaged asbestos. binders to hold the fibers to gether. With age, the plasters or binders holding the fibers to gether disintegrate allowing them to be exposed to the air and poten tially be released into it. Asbestos products such as vinyl asbestos fioor tiles and house sid ing are much less likely to disinte grate. These materials cause problems only when ground to dust. "Friable" is a term used to indi cate asbestos in a badly damaged condition, such that is capable of releasing fibers into the air. The definition is "easily crumbled or turned to powdery dust by hand pressure." Obviously, this is a very bad definition in that it en courages a person to do exactly what should not be done -- i.e. to check for friability by seeing if the material can crumble easily, thereby potentially exposing him self to airborne asbestos. Because of this fact, the friability of asbestos should only be evaluated by experienced or specially trained personnel who . LkbUity... 1 Since the only actual standards : samples to be useful they must be tor permissible exposures to .; compared to values obtained vairbome asbestos fibers apply ? from air sampled outside on a dry ^ exclusively to Ihe occupational day and analyzed the same. setting, the formulation of levels ! This method can be illustrated considered safe for the public, or by looking at a large metropolitan in public buildings, remains an ,`alrport which has a considerable unsettled issue. The employer is 'amount of sprayed-on asbestos in protected from excessive claims the restricted access baggage against him for asbestos-related handling areas, but none In the occupational disease because the 'public areas. To decide on the payments are made through the appropriate control technology, Workmen's Compensation system; bulk and air sampling and but this Is not the case for the physical assessment must be done building owner when people who. in those baggage areas. To are not his employees are using jaddress the issue of potential the building. owner liability, air samples need to Because there is concern be taken in the public preas of regarding both building owner T; me terminal [such as the liability and the size of claims baggage claim area) and then which may be leveled against th$ tanalyzed by the more sensitive, building owner by the courts in i' more expensive electron the future, building owners tend to - microscopy. be extremely thorough and -T i The results from both sets of conservative when trying to assess samples must then be compared the degree of asbestos hazard to outdoor samples taken either in within their buildings. the uncovered parking garage or The state-of-ihe-art analytical in a near-by shopping center method for determining the air parking lot. concentration of asbestos fibers Is : The typical cost for a bulk to count the fibers on a filter by. pnolysis by polarized light scanning electron microscopy, or microscopy and X-ray diffraction, transmission electron microscopy, Combined, is $30-$35. The same rather than by the NIOSH- fr tost is typical for a filter sample of approved methods tor bir analyzed by phase contrast occupational exposures (using microscbpy. Scanning electron light microscopy). This method . jnlcroscopy or' transmission makes the smaller and thinner ' electron microscopy will range fibers substantially more visible by;.,^ from $300-$500 per sample, and is providing a magnification of 4,000^ jjsed only where building owner to 10,000 times, rather than 400 liability, as opposed to employer times. For the values from the air liability, is being considered. S2 APRIL 1985 A04397 are aware of the problem and use adequate protection. Friability is a term best used to denote and evaluate the condition of asbestos sprayed onto beams and ceilings in public or commer cial buildings. However, only in rare cases does it apply to badly damaged pipe lagging or the covering of old furnaces and boilers. Since pipe lagging is usu ally not friable, any potential as bestos fiber release can be elimi nated by.having the pipes rewrapped by an experienced pipe lagger. 4 ii r t i >r> 5 r- Asbestos In schools and public buildings Many schools and university buildings constructed during the "baby boom," right after World War II, or to accommodate the returning GI's, are still in use. They are prime examples of where asbestos may have been sprayed onto ceiling or beams. In addition, they may have asbestos on the pipes (lagging) or around the boilers. The Environmental Protection Agency has mandated through federal law that all schools must take certain steps with regard to asbestos building materials which may have been used in them. However, one cannot be sure the material is asbestos until it has been analyzed by a laboratory. For that reason, they refer to the ma terials simply as "friable". Risk assessment far friable asbestos Since only airborne asbestos is a health hazard, it is not neces sary to arbitrarily remove all as bestos in a building. Removing it will eliminate the problems once and forever, but if the cost or logis tics are prohibitive, other meth ods of control should be consid ered. The composition of the asbestos, its location and condi tion, as well as the degree of damage, should all be used in arriving at a decision regarding measures. There have been two important (continued) \ fi an fee op an The gives wher ASBESTOS Two rating systems assess the degree of risk. rating schemes developed which attempt to facilitate these deci sion-making processes. The first method originated with Dr. Ben jamin Ferris, at the Harvard School of Public Health; the sec ond approach is from the Cana dian Ministry of Labour. In the Ferris rating scheme, the Ferris Index equals an expression made up of the variables express ing accessibility, condition, friability, location and percentage of asbestos: Ferris Index = (A + C+F+DxP; A = Accessibility, C = Condition, F = Friability, L - Location and P = Percentage. Accessibility is the ease with which the asbestos fibers can be come airborne as a consequence of the architectural design, the loca tion of the asbestos, or the activi ties which are occurring in the building. It is rated 1-4, as follows: 1 = Totally enclosed (i.e. behind a suspended ceiling); 2 = Inac cessible, beyond the reach of the population using the building; 3 = Accessible in low activity areas only; and 4 = Accessible in high activity areas such as gyms, caf eterias, hallways and stairways. Condition of the asbestos is rated by Dr. Ferris according to the degree of visual degradation, rather than encouraging tests for friability: 1 = No damage at all, the condition is very good; 2 = Mild damage; 3 = Moderate damage; and 4 = There is evi dence of severe damage with areas missing, hanging loosely or showing signs of delamination and water damage. Friability of the material is rated from 1-4. It is the extent to which the material can be broken apart when a person or object makes contact with it. This is where the hazard from pipe lag ging typically becomes less severe in the rating scheme, because 94 APRIL pipe lagging is rarely as friable as ing which has never contained sprayed on asbestos. The ratings any friable asbestos building ma for friability follow: terials. I = Non-friable or firmly To ascertain what the air con bound; 2 - Slightly friable; 3 centration of asbestos is, one can Moderately friable; and 4 = Very arrange to have air sampling done friable, breaks apart with very lit by an industrial hygienist, or a tle pressure. qualified laboratory. While there Location -- a value of 1 is in are certainly many competent cluded in the equation if the ma people providing this service, the terial is not in an air plenum; but American Board of Industrial a value of two is used if it is. An Hygiene has a certification pro air plenum is the mixing chamber gram for industrial hygienists, for the return air which may be and the American Industrial recirculated throughout the Hygiene Association certifies lab building. oratories. Percentage of asbestos con The industrial hygienist will tained in the material is rated as set up a small portable pump in follows: 0 = Less than one per the location of concern and draw cent; 1 = One to ten percent; 2 = air at a pre-set rate through a spe Eleven to twenty-five percent; 3 cial filter for a measured length of = Twenty-six to fifty percent; and time -- typically 2 to 4 hours -- at 4 = Fifty-one percent or more. 2 liters of air per minute. The fil All of these values are plugged ter traps all the asbestos fibers, into the following equation: Fer plus other dirt and dust in the air. ris Index = (Access. + Cond. + At the laboratory, a technician Fri. + Loc.) x Percent. cuts a pie-shaped wedge out of the The recommended actions are filter and mounts it on a micro as follows: 0 - 4, No action; 5-9, scope slide. The filter material is Review in 2 to 3 years; 10 -15, Re view in one year; 16 - 20, Either surveillance or control; and 21 or over. Control. dissolved, leaving the dust and fibers visible to the trained eye with phase contrast microscopy. Thus, the fibers on a known area Another decision-making crite ria to be used is air sampling. Since asbestos is not hazardous until it gets into the air as micro scopic fibers, measuring the air borne concentration of asbestos of the filter are actually counted and calculations are performed to determine how many asbestos fibers there were per cubic centemeter of air. provides additional complemen tary information. The units of measurement for air sampling are fibers per cubic centimeter of air. Fbr units of fibers per liter, divide by 1,000 to compare the results to fibers/cc. To get the units of fibers per cubic meter, fibers/cc should be divided by one million for com parison. Air quality standards far asbestos Unfortunately, there are no standards as to what concentra tion of asbestos fibers in the air are legally acceptable for the pub lic to breathe. The occupational health laws have been very spe cific about what a "normal healthy adult worker" may experi The air inside a building cannot be expected to be any cleaner or to contain less asbestos than normal outside air. (The filters on a fur ence while on the job, and data exists as to the typical outdoor concentration. When the asbestos concentra nace simply do not trap the invisi tion inside a building is elevated ble microscopic fibers.) In the out over the outside level, but is not door environment there are necessarily high enough to re typically 0.003 fibers/cc in rural or quire action under the occupa suburban areas, and 0.005 fibers/ tional health and safety laws, cc in urban areas. This is also the plans and decisions must be made air level to be expected in a build (continued/ A04390 In 19 and : Bard. dowr gercient remo' Fuelir drive inent mark Dunn comn. a broa Comm earnin in buil descrif ASBESTOS Removal is definitely not a job for amateurs to remove or control the asbestos in both a conservative and a rea sonable manner. The present OSHA occupa tional health standard for asbes tos specifies a maximum 2 fibers/ cc time-weighted average expo sure, and a 10 fibers/cc ceiling con centration for asbestos. As of Summer 1984, there have been several sincere, but as yet in complete attempts to lower this permissible level. A proposed tem porary emergency standard of 0.5 fibers/cc was struck down by the courts on a technicality. Imme diately, the federal Office of Man agement and Budget submitted a revised proposal for an even more strict standard, 0.2 fibers/cc. Despite what the rules say, most people are willing to act rea sonably and minimize exposures to asbestos. Within many stateoperated OSHA programs, the "action level" for airborne asbes tos is set at 0.1 fiber/cc., consider ably lower than the standard it self. This is the air concentration at which an employer is expected to start taking serious steps to reduce his employee exposures. It is also the concentration at which the employer needs to provide medical exams, air monitoring and elaborate record keeping. This action level of 0.1 fiber/cc is also a very significant level for the public to be aware of in deciding what to do about asbestos build ing materials. If the air levels are distinctly below 0.1 fiber/cc, or close to the outdoor level of 0.005 fibers/cc, a program of surveillance may be appropriate. But, at an airborne level above 0.1 fiber/cc, steps to remove or control the asbestos are necessary. Between 0.01 fiber/cc and 0.1 fiber/cc, it is most appro priate to retain the services of an experienced professional indus trial hygienist. A U 4 3 9 ' 11m asbestos control options available There are four common pro cedures which can be used to con trol friable asbestos: (1.) sur veillance; (2.) encapsulation; (3.) enclosure; and (4.) removal. It is extremely important that care be taken to plan the operation well, as there have been documented cases where enthusiasm instead of wisdom has increased airborne asbestos levels rather than con trolling and lowering them. Surveillance is not simply a matter of avoiding action in an asbestos problem, but rather a procedure of establishing records that the materials have been in spected at pre-determined inter vals to look for evidence of damage. The records should in clude a photograph or two, plus the date; the results from air sam ples, if taken; and the name of the person! s) responsible for the in spection. It is not a program of avoiding action, but rather of ver ifying that deterioration has not occurred. Encapsulation entails spraying, coating or painting the asbestos with a bonding sealant which will keep the asbestos fibers well glued together, and eliminate any chance of friability developing. There are two types ofencapsulat ing products commercially avail able: penetrating sealers which soak into the asbestos and glue the fibers together; and bridging encapsulants, which form a con tinuous membrane on the surface which is impervious to fiber pen etration. The two methods may be used separately or in combina tion. Encapsulation is especially well-adapted for pipe lagging and may include covering the pipes with a pre-wet fiberglass cloth or vinyl wrap. It can also be used with boilers, but there are distinct limitations in using it with sprayed on ceilings. Since the sealant rarely penetrates the as bestos further than about it will add weight to a ceiling and may encourage dclammalion. The EPA has devised a very useful decision guide for determining when it is appropriate to choose encapsulation. Very often enclosure is chosen as a control method in combina tion with encapsulation. Exam ples would be putting in a sus pended ceiling or a false ceiling to limit the accessibility to overhead pipe lagging. Rarely should en closure be used by itself; but if one has decided to use regular planned surveillance and/or en capsulation, enclosing the asbes tos may be both an effective and appropriate additional method of control. Enclosure is not a method to be recommended for badly damaged or friable asbestos ceilings, since the carpentry work of adding the enclosure would in itself greatly increase the asbestos fibers re leased into the environment. For badly damaged friable as bestos, removal and disposal in an approved hazardous waste dis posal site may be the only appro priate method of control. How ever, removal is not a simple procedure. The project must be handled by an experienced con tractor with a trained crew. As the initial step, the entire removal area will be isolated from the re.it of the building with a heavy sheet of vinyl plastic. A double air-lock must be constructed to eliminate the possibility of the fibers escap ing outside the removal area, and the interior must be controlled with exhaust ventilation with high efficiency particulate filters to keep it under negative pres sure. The asbestos must be damp ened with a low pressure spray of water containing a wetting agent, and then removed wet. Asbestos removal is definitely not a home-owner or building- manager type project. It requires elaborate controls to guard against the infiltration of asbes tos into other areas of the build ing and/or the outdoor environ ment. It also necessitates that the workers be protected with respi rators, disposable clothing, and medical surveillance. rm 96 APRIL For more Information from Davies-Young Co., circle No. 460 on Data C;