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3.1 GENERAL INFORMATION

The committee discussed if the recommendations considered by the committee are technologically feasible. White defined technological feasibility as the ability of most operations in each industry affected to comply with a Permissible Exposure Limit (PEL) most of the time (M9:30). Robert Burt from OSHA's Office of Regulatory Analysis, indicated that an action is technologically feasible if it can be done in most operations (M2:4). Burt noted that if there are companies that meet the regulatory requirements, and/or technology is currently available or soon will be, the action is technologically feasible (M2:4). Estimations of feasibility can be based on: data from existing operations, data from similar operations, data from demonstrations, application of "rules of thumb", observation of exposure trends and technology forcing (O'Brien, 1998).

Members used "technically" and "technologically" as synonyms throughout the discussion (M9:30-31). The third and sixth meetings focused on technological feasibility and this issue was discussed at other meetings and addressed by site visits by work groups to small, medium and large facilities using MWFs.

In order to understand if an action is technologically feasible, it is necessary to determine what current conditions are and the factors that are important in reducing exposure and protecting workers from MWFs. The committee focused on systems management and exposure control. It is very difficult to separate the issues of systems management and exposure control, since the latter is part of the former. Additional information on systems management can be found in Chapter Six, Best Practices for Systems Management. Exposure assessment and medical surveillance were also discussed in the context of technological feasibility and these topics can be found in the Chapters Seven and Eight of this report.

3.2 SPEAKERS AND PRESENTATIONS

Committee member, Dr. Hank Lick, provided an overview of systems management and addressed exposure control (M2:15-17). Another committee member, Frank White discussed the development of the ORC Guide for Systems Management of MWFs (M2:16). Stephen Gauthier, a machinist at a large East Coast manufacturer described his own experiences with controlling dermatitis using systems management of MWFs (M2:17-18; M8:18-19). Charles Guy, Ford Motor Company, addressed issues of worker acceptance of control technologies (M3:7). Tom Beeman, a machinist at a mid to large facility in the Western part of the US provided some limited information about his company's fluid management (M5:3). Dr. Henry Anderson, committee member, explained some system factors in his study of an HP outbreak in Wisconsin (M5:3-4). Dr. Daniel Goon, Castrol, addressed issues related to systems management during his participation in a panel discussion (M5:23). Dr. Harold Rossmoore described the importance of the microbiology of MWFs and its relation to systems management (M5:19-20). A panel of machine tool manufacturers, and ancillary companies that support the design and installation of machine tools and enclosures in machining facilities, discussed enclosures and systems management (M6:6). The panel consisted of Jeff Hedley of Tamer Industries, Stephen Stevens from Cross-Huller; William Fay from H.M. White, Dan McCarthy of Lamb Technicon, Ken Steele of Grob, and Al Woody of Giffels Associates (M6:6). Charles Carlson of the Association for Manufacturing Technology also joined this panel (M6:7). Dr. Robert Adams, Professor Emeritus from Stanford University and practicing clinical dermatologist addressed the group (M2:2-3). Adams, and Dr. Boris Lusniak from NIOSH, explained the skin problems associated with exposure to MWFs and how these problems can be controlled (M2-3;13-15). Committee member Dr. Frank Mirer referred to exposure control in his presentation on exposure measurement (M2:12). Committee member, Dr. Dennis O'Brien provided an overview of the available control technologies for reduction of airborne MWFs (M3:1-2). William Johnston, Ford Motor Company, provided a review of the ANSI B11 Mist Control Document and gave his perspectives on technology design (M3:2-3). Dr. David Leith, University of North Carolina, explained mist collector performance (M3:3-5). David Hands, Ford Motor Company, presented data on the effectiveness of enclosures (M3:5-7). Robert Kramer, Ford Motor Company, addressed some technological feasibility issues in his discussion of economic feasibility (M3: 6,910) Dr. William Watt and Jack Hartwig, Chrysler Corporation and Dr. James d'Arcy, General Motors provided their companies' experiences with the technology needed for MWF control (M3:7-9). A panel consisting of Kramer, Watt, Hartwig, d'Arcy and committee members, Dr. Frank Mirer and Arthur McGee addressed the issue of economic and technical feasibility in the American auto industry (M3:11). Greg Piacitelli from NIOSH discussed exposures and controls found in the small businesses surveyed in the NIOSH Small Business Study (M4:1). Dr. Ed Stein, OSHA, provided background information on previous OSHA and NIOSH recommendations for dermatoses (M5:28-29). Robert Burt, OSHA addressed technological feasibility in his presentation of OSHA's work on feasibility (M7:24). Ike Tripp, Etna, addressed issues on systems management as part of a discussion of the ORC Document (M8:8). Michelle Lantz, Caterpillar Corp, discussed systems management factors that can reduce health concerns (M8:10).

3.3 BACKGROUND INFORMATION

3.3.1 Components of Systems Management

Lick noted that many different issues are encompassed in systems management (M2:12). These include: fluid application, MWF cycling, tool speed, part loading and unloading, chip removal, types and effectiveness of enclosures, lock out, exhaust ventilation, supply air, duct design, air cleaner quality, fire protection, and waste disposal (M2:15-16). The systems work group defined the role of a systems approach as managing the fluid, integrating and controlling systems that result in exposure control and enhanced coolant and machining performance (M8:3). Systems approach and control are modern management practices for continuous improvement and avoid the "whose problem is it" phenomenon (M8:3). Engineering controls provide enclosure and removal of mist using ventilation and provide improved housekeeping (M8:3). Fluid management maintains the quality of fluid and deals with unknown hazards e.g. microorganisms (M8:3).

White explained that systems management also includes: a written management program with stated goals, a designated individual in charge, written standard operating procedures for fluid testing and data collection, a tracking system for determining trends, and a training program (M2:16-17). Lick and White highlighted the importance of employee participation and feedback (M2:15,17).

White noted that use and maintenance of the fluids are integrally related to issues such as ISO 9000 (M2:16). More companies are realizing that product quality and fluid management are related, according to White (M2:16). The systems work group viewed that systems management could be put into an overall ISO program as it was done at Valenite, but ISO programs are not a replacement for OSHA action (M8:3). The systems work group recommended streamlining any information gathering required or recommended by OSHA so that multiple uses of the information could be served (M8:3). Making the fluid management system integrate with ISO can be useful and Howell recommended that OSHA consider this aspect (M8:3).

Burke cited 10 steps for better management of the fluid: use good water, maintain pH, control concentration, use established biocides and follow biocide use guidelines, fix leaks, pick the right fluid, filter the fluid, dispose of old fluid and enclose the machine (M6:29).

Guy noted the term dry floor guarding, another name for full enclosure of a machine and its fluid (M3:7). Dry floor guarding is the part of systems management that keeps the mist out of the air, MWFs off workers and makes it easier to see in the plant (M3:7). He stressed the importance of team work and training (M3:7).

The fluid supplier's part of systems management is a product stewardship program, according to Howell (M4:4). Product stewardship includes: policies, management practices, fluid customer education, outreach, product selection guidelines, accountability and performance evaluation, according to Howell and Goon (M6:35; 8:11). Management commitment includes leadership and resources to integrate health, safety and environmental considerations into the design, manufacture, responsible use and disposal of MWFs (M8:11). More on product stewardship is in Chapters Six and Nine.

Additional details of systems management are provided in Chapter Six, Systems Management in the Best Practice Section of this report. Additional references are found in Attachment #6.

3.3.2 Enclosure Technology for MWFs

An important part of systems management is the enclosure technology used to reduce mist exposure and lessen contact with MWFs. Mirer defined direct airborne exposure as that from a specific machine to that machine's operator, and indirect exposure as that to anyone else due to carry-over from work stations (M2:12). He described the exposure sources as the machine, the fluid recirculation system, the air cleaner recirculation and the carry-over (M2:12).

O'Brien explained the different ways MWF mists are generated (M3:1). There is not any average particle or average mist due to different processes, types of MWFs and concentrations (M3:2). O'Brien highlighted the use of general and local exhaust ventilation to remove mist (M3:1). Hood designs include receiving, capture and enclosure types (O'Brien, 1998). He noted that enclosure type hoods are the only type recommended by the ANSI B11 committee on Mist Control (O'Brien, 1998).

O'Brien provided an overview of the different types of mist removal, mechanical, filtration and precipitation (O'Brien, 1998). Filtration is the most common approach and he noted that filtration efficiency depends on particle size (O'Brien, 1998). Volatile compounds may evaporate from the filter and the filter media may support microbial growth (O'Brien, 1998).

3.3.3 Other MWF Controls

Details on how the fluid can contact skin are provided in Chapter Two of this report. It is critical to reduce contact with the fluid both by direct contact and airborne exposure.

Substitution is a strategy used in fluid management and is part of fluid selection (M8:4). Howell recommended any user to ask suppliers for information on their products (M8:4). See Chapter Six for more discussion on Product Stewardship.

 
3.4 REVIEW OF AVAILABLE INFORMATION

3.4.1 Experiences and Resources Related Fluid Management Technology

Gauthier cited the improvement in his moderate to severe contact dermatitis by applying systems management techniques (M2:17). Gauthier monitors fluid concentration, pH, hardness and tramp oils and charts these variables (M2:17). Gauthier uses a hand held computer to enter these variables for future analysis (M8:18).

Gauthier stressed control of microbial growth, proper selection of fluid, prevention of contamination, proper use of biocides, filtration and cleaning of the MWF system (M2:18). His company installed a chip filtration system and through his efforts paid attention to fluid management (M2:18). He writes articles for union and company publications to enlighten workers and management (M8:18). His systems management group meets monthly to identify and solve problems and there is a quick response team to address a crisis (M2:18). In a crisis, this team immediately checks current values and trends in pH, hardness, concentration, and tramp oils, visually assesses residue and ventilation, and makes recommendations for action (M8:19). He cited one example of microbial contamination exceeding 105 organisms per ml of MWF and how the company supported the recommendation to dump and clean out the system (M8:19). No health effects were seen due to prompt action (M8:19).

Gauthier explained that eating and drinking are not allowed on the shop floor although work clothes are taken home at his site (M8:18). He cited a problem with shop rag cleaners and has found a less irritating cleaner for the company that cleans the rags (M8:18). He thought people should view MWFs as a liquid tool to take care of and use effectively (M8:18). Gauthier noted it took five years to implement the changes that resulted in his improved health (M2:18). More details on Gauthier's program, its benefits and some diagrams of components can be found in his handout materials (Gauthier, 1997).

Beeman noted that there was very little fluid management at his facility (M5:3). Some machinists did limited fluid checks on their own machines (M5:3). Further information on his experiences is found in this report in the non-cancer respiratory section of the chapter on health issues.

Microbial management is important according to Rossmoore (M5:24). He recommended keeping the number of organisms in the sump below 105 to 106 organisms per ml of MWF and Goon agreed (M5:24). Fluctuating biocide and microbial levels can result in resistant bacteria and fungi, according to Rossmoore (M5:24-25).

Biocides and fluids have to be compatible, according to Goon (M5:23). The history of biocide use is important because slug dosing can allow the build up of endotoxin (M5:24). Goon and Rossmoore noted that slug dosing is an example of improper fluid management and a likely cause of evacuations or sudden irritation (M5:23). Tank side addition of biocide should be avoided; it is better to add fresh concentrate, replenishing the original chemistry, according to Goon (M5:25).

Anderson noted a dramatic change in biocide use during the HP outbreak he studied (M5:4). Biocide use doubled to tripled in the months prior to the peak of the outbreak (M5:4).

Burke outlined causes for health effects at his facilities including: over-addition of biocide, use of monoethanolamine or pine oil, overgrowth of bacteria, miscalculation of fluid concentration and shutting off plant make-up air (M6:27). He warned against fluid formulation problems such as improper matching of biocide and MWF, the use of a lacrimator biocide, inconsistent product quality and purchase of bad smelling oils (M6:27). He highlighted the importance of minimizing tramp oil, noting that zinc dialkyldithiophosphate is an excellent culture medium for bacteria (M6:28). Suppliers sometimes provide incorrect information to plants (M6:28). Proper fluid selection can solve dermatitis problems, according to Burke (M6:28). More CNC machines are in use in mid size plants and these have enclosures (M6:28). Increased cutting speeds test fluids, enclosures and designs (M6:28).

Kushner explained his company's MWF management program that includes four lubricant engineers overseeing the program (M6:32). There is rigid screening and selection process for fluids using various tests (M6:32; M8:4). He noted that if the fluid passed these tests, it was less likely to have adverse health effects because the chemistry stays intact and additive use is minimized (M8:4). Kushner's company has never used a nitrite containing fluid (M6:32). He noted that his company only uses four to six fluids and once it selects a fluid, stays with it (M6:32; M8:4). Daily and weekly fluid testing of the in use fluid is done (M6:32). Kushner noted that systems are routinely dumped once per year and are constantly circulated to maintain less than 105 microorganisms/ml of MWF (M6:32). His company rarely uses tankside addition of biocides (M6:32).

Lantz stated that greater than 0.2% particulate in many MWF systems indicates an inadequate fluid filtration system (M8:9). Concentrations of contaminants that are allowable may be different for different fluids (M8:10). She stressed the importance of finding problems early and solving them before a health effect occurs (M8:10). If one person has a complaint, she views that there is a problem with MWFs (M8:10). She noted the importance of a MWF committee and of talking with the "oiler", the person who adds hydraulic fluid to machines (M8:10). This individual knows what machines are leaking (M8:10).

Frederick noted that some of the activities done as fluid management are also part of exposure assessment for dermal exposure (M8:24). He noted that fluid management would reduce potential exposure to endotoxins and excess biocides (M8:24).

Other issues were addressed briefly. Howell noted that it may be important to occasionally check for Mycobacteria in systems to prevent HP (M8:25). The potential for automation of pH and bacterial counts was discussed by Teitelbaum (M5:29). Some companies use single purpose lubricants that function as MWFs and as lubricants, lessening the opportunity for tramp oil contamination. Tripp explained that single purpose lubricants are difficult to use on older machines because of machine characteristics like tolerances (M8:9). The variety of machine types require formulations to develop many different fluids (M8:9).

3.4.2 Additional Information about Fluid Management from the NIOSH Criteria Document

The NIOSH Criteria Document places fluid management under work practices in section 9.3.1 of the document (NIOSH, 1998). Ways of minimizing mist generation, fluid evaluation and selection and fluid maintenance are noted (NIOSH, 1998). NIOSH recommends monitoring of the fluid level in the sump, MWF concentration, fluid pH, microbial counts, and the degree of tramp oil contamination and notes that monitoring should be done more frequently in warm weather (NIOSH, 1998). NIOSH views that what constitutes a safe microbial level has not been established and this contradicts Rossmoore's recommendation of less than 105 to 106 organisms/ml of fluid (NIOSH, 1998). NIOSH recommends adding premixed fluids, not concentrate, and urges time limits on storage of fluids (NIOSH, 1998). Other issues such as servicing, aerating, and cleaning are addressed (NIOSH, 1998). Judicious use of biocides is stressed (NIOSH, 1998).

3.4.3 Additional Resources for Fluids/Systems Management

The second edition of the ORC Document on Metal Removal Fluid Management was outlined for the committee (M8:6). d'Arcy noted in addition to the items listed above, the importance of active management of the fluid and attention to the facilities and equipment used (M8:6). Quality assurance and self assessment can help manage the system (M8:6). Selection of a fluid supplier was outlined by Howell (M8:7). Misting characteristics, raw materials and the toxicity of the whole fluid as compared to the components are important for fluid selection (M8:7). More information on the ORC document is in Chapter Six.

Another source noted by Howell is the National Center for Manufacturing Sciences (NCMS) Fluids Optimization guide (M8:7). The 10 year old ASTM E1497 Standard Practice on Safe Use of Water Miscible Fluids addresses concerns such as additives, biocide use, system design and worker protection, according to Howell (M4:5). This ASTM document is due for review by ASTM (M4:5).

Handouts provided by Rossmoore and Stein provide additional information (Rossmoore, 1998; Stein, 1998a-d). Rossmoore's company, Biosan, Warren MI, can provide a list of additional references for microorganisms in MWFs. Additional details of systems management are provided in the section on Systems Management in the Best Practice Section of this report (M8:6).

3.4.4 Research and Experiences Related to Enclosure Technology

3.4.4.1Speakers' Comments

Johnston outlined the ANSI B11 Document on Mist Control and recommended its use in a company's decision making (M3:2,3). He explained how MWF delivery design can influence mist generation and the flume can be an additional source of mist (M3:2). Johnston noted that this design document stresses the use of enclosures and explained some important features such as: telescoping doors for easy access, interlocks, easy overhead access and mechanical assist devices to avoid ergonomic problems (M3:2). Enclosure seals must be compatible with the MWF to avoid leaks due to seal degradation according to Johnston and Watt (M3:2,8). Take offs for enclosures should not be positioned to catch chips, these should end up in the trench, not the ducts (M3:2). Ducts should be designed to enhance mist collection in the ductwork by using slower duct velocities and sloping ductwork (M3:2). More details can be found in the ANSI B11 document (1997).

In additional discussion of technical feasibility, Johnston stressed that only a ventilated enclosure will reduce exposure to 0.5 mg/m3 (Johnston, 1998). The tighter the enclosure, the less ventilation needed to keep the system under negative pressure (Johnston, 1998). New machine enclosure are preferable due to effectiveness and less problems working around production and existing structures (Johnston, 1998). A cross functional team including the following is needed: process engineer, OEM machine builder, enclosure sub-contractor, machine operator, mechanical engineer and safety/environmental engineer (Johnston, 1998).

Leith outlined his research group's study of mist collector technology (M3:3-5). He noted that the best filter will have the highest fractional efficiency curve, i.e., it will effectively collect droplets of all sizes (M3:3). He stressed the importance of pressure drop across a filter, the difference in static pressure between the inlet of a collector and its outlet (M3:3). Leith noted that a high pressure drop does not necessarily mean high collection efficiency but pressure drop will affect the filter's cost of operation (M3:3,4).

According to Leith, multi-stage filters have a Iow efficiency pre-screen, second stage of either a pocket filter, renewable fabric, roll-type media or cartridge filter, and a final stage of either a 95% DOP filter or HEPA filter (M3:3). The first and second stages reduce the loading on the very effective, but short-lived HEPA filter (M3:3). With good first and second stages, the HEPA filter can have lifetime of a year (M3:4). HEPA filters are very effective for capture of fine particles (M3:5).

From his research, Leith recommends a first stage metal mesh filter, either a pocket filter or good cartridge for the second stage, and a final HEPA filter (M3:4). The second stage's efficiency needs to be monitored due to particle loading (M3:4). Deterioration of the second stage can result in a premature loading of the final stage and drop the final stage efficiency in half (M3:4). With well maintained HEPA filters, mist concentrations re-entering the workplace can be 0.05 mg/m3 (M3:4). Additional details on the test methods Leith used can be found in his handout (Leith, 1998).

Hands presented two studies comparing airborne MWF exposures with different levels of enclosure (M3:5). One study looked at already collected exposure data and categorized the exposure controls associated with the data (M3:5). The control categories were three types: original equipment manufacturer (OEM) or total enclosures, retrofit or partial enclosures, and no enclosures (M3:5). For this study, the median exposure for the OEM enclosures was 0.21 mg/m3, for retrofit was 0.45 mg/m3 and for no enclosures was 0.45 mg/m3 (M3:5). OEM was significantly different from the other two conditions (M3:5). Due to the retrospective nature of the study, there were many uncontrolled variables (M3:5). For more details about this study, see Hands et al, 1996.

Hands described a second study that compared two existing transmission case lines, one with OEM technology and the other with retrofit, partial enclosures (M3:5). The two lines were identical except for the degree of enclosure (M3:5). The OEM line had significantly lower personal and area airborne concentrations and more consistently lower results (M3:6). 10% of the OEM line exposures exceeded 0.5 mg/m3 (M3:6). For more details, see his handout (Hands, 1998).

Guy outlined the improvements enclosed transfer lines provide for workers (M3:7). Guy noted that transmission plants typically run shifts on case lines of 10 hours per day, 6 to 7 days per week due to demand (M3:70). He cited the conditions present when only perimeter type guards were available where mist levels were so high that workers had to ring out their time cards (M3:7). When only perimeter guards were available in the 1980s, the case lines were always a source of complaints, according to Guy (M3:7).

Watt noted that retrofit enclosures are used to upgrade existing conditions because typical machine tools have an average lifetime of 28 years (M3:8). He outlined the difficulties finding skilled workers called tinnies to make the retrofit enclosures (M3:8). Lines have to be shut down to retrofit or retrofitting is done during scheduled downtimes according to Watt (M3:8). Even with the best design retrofit machines, 7-8% of them will exceed 0.5 mg/m3 (M3:8). Watt was concerned about the difficulty retrofitting around moving machining heads, parts, pallets, loaders and hoists (Watt, 1998).

Watt viewed the best enclosure as a room size one that spans the entire operation and uses access doors (M3:8). He noted that these enclosures require high ventilation rates (M3:8). He worried that even these enclosures would not protect a sensitized individual (M3:8). Degradation of the enclosure due to seal failure, gaps, and covers not replaced combined with increased MWF flow, allow mist problems to develop (Watt, 1998).

Hartwig cited the importance of make up air and tempering this air as needed (M3:8). He was concerned about the trends in machining to higher pressures and higher tool speeds which will challenge the integrity of enclosures (M3:9).

d'Arcy explained that air probes are used in machining to flush out chips from deep holes (M3:10-11). He urged replacing the use of air probes with fluid flushes to significantly reduce mist production (M3:10). d'Arcy noted that the air supply house can significantly contribute to the mist load in recirculated air (M3:11). In air conditioned plants, more air is recirculated in the summer than in the winter according to d'Arcy (M3:11).

Mirer highlighted the feasibility of enclosure, easy access, exhaust to achieve 150 fpm capture through openings and a 3 stage collector with HEPA (Mirer, 1998a). He explained that other feasible controls are flume enclosure, MWF cycling, fluid maintenance, improved air cleaning and vapor capture (Mirer, 1998a).

3.4.4.2 NIOSH Small Business Study Results

Hughes provided a demonstration of the database of the NIOSH Small Business Study (Hughes, 1998). Over 50 variables can be assessed using the database (Hughes, 1998). The NIOSH database provides exposure and control information about small business.

Piacitelli explained that 25-26% of the machines in the shops surveyed in the NIOSH Small Business Study had full enclosure, about 20-25% had partial enclosure, about 33-40% had splash guards and the remaining had no controls (M4:1; M7:3). Air handling systems for general ventilation were rare in these plants (M4:2). Thirty percent of the total particulate samples were less than 0.25 mg/m3, 63% of the exposures were less than 0.5 mg/m3, 88% were less than 1.0 mg/m3, and all but two of the 940 samples were less than 5.0 mg/m3 (M4:1). Comparing NIOSH data to the OSHA database, Piacitelli noted that OSHA found 65% of samples were below 0.5 mg/m3 (M4:2). In the NIOSH study, using thoracic sampling data, all were below 5.0 mg/m3, and 75% were below 0.5 mg/m3 (M4:1). Background values in non-machining areas were 0.06 mg/m3 for total and 0.04 mg/m3 for thoracic, according to Piacitelli (M4:1). Smoking may have contributed to the background values (M4:2).

Piacitelli explained that the average plant in the NIOSH Small Business Study had 51 workers, 45 operating machines and used 4000 gal of MWF/year (M7:2). The average machine density was two machines per 1,000 square feet of floor space or one machine per 10,000 cubic feet of room volume (M7:2). Twenty seven percent of all facilities made screw machine products (M7:3). Turning operations made up 45% of all samples (M7:3).

According to Piacitelli, fifty percent of samples from turning operations were less than 0.5 mg/m3 (M7:4). For grinding: 35% of the aerosol was respirable (<3.5 m) and 65% was in the thoracic range (<9.8 m) (M7:3). Hobbing produced 60% respirable particles (M7:3). For the four major types of operations, 60-70% of the aerosol was thoracic (M7:3). Forty percent of the samples were taken in areas using straight fluids and these fluids produced the highest geometric mean concentrations (M7:3). Soluble produced the next highest followed by the semi-synthetics and synthetics (M7:3).

Seventy percent of plant mean exposures, according to Piacitelli, were less than 0.5 mg/m3 and 90% were less than 1.0 mg/m3 (M7:4). Eighty percent of shops had at least one sample over 0.5 mg/m3 (M7:4). Twenty-two plants had 50% of their samples above 0.5 mg/m3 and 10 shops had 100% of their samples over 0.5 mg/m3 (M7:4). Of the plants predominantly using straight fluids, 22 out of 24 plants had at least one sample greater than 0.25 mg/m3 (M7:3). For thoracic sampling, 40% of shops had at least one sample greater than 1.0 mg/m3 (M7:4).

Piacitelli noted that samples taken in areas with full enclosure had a geometric mean of 0.4 mg/m3 and 65% of these samples were less than 0.5 mg/m3 (M7:3). All the full enclosures were OEM (M7:3). Sheehan noted that for the same conditions in the Hands study, 90% of the samples were less than 0.5 mg/m3 (M7:3). Piacitelli's study looked at individual machines, while Hands' study investigated transfer lines (M7:3). Piacitelli explained that in areas without total enclosure but with local exhaust ventilation, the exposure was about twice that of the total enclosure (M7:3). Interpretation on other degrees of enclosure was limited due to sample size (M7:3).

Piacitelli noted that the average machine age was 20 years in shops whose geometric mean was less than 0.5 mg/m3 and 25 years in those whose geometric mean was greater than 0.5 mg/m3 (M7:4). Lick noted the similar numbers found by an AMT study (M7:5). The majority of the control technology was on machines less than 10 years old, but 85% of all machines had some degree of control (M7:4).

Preliminary analysis indicated that a trend of higher exposure with older machines was significant (M7:4). O'Brien noted that subsequent multivariate analysis demonstrated that exposures were lower in plants where the mean age of equipment was higher. Flooding was the most common fluid application noted during the small business study (M7:6).

Exposures in the NIOSH Small Business Study were found to be higher for operations on machines with enclosures than those without enclosures. An explanation could be that enclosures were not employed on machines using processes that inherently produce less mist. Another possible explanation is that different types of machine tools with different mist generating capacities produce different exposures.

3.4.4.3 Machine Tool Industry Representatives' Comments

McCarthy explained the importance of machine guarding and that the enclosure adds to the guard and is a selling point (M6:9). McCarthy noted the history of enclosure development from guard to splash guard to total enclosure and highlighted Grob's European experience changing the US market (M6:9). Steele explained that Grob does not build a metal cutting machine that is not totally enclosed to contain mists and that this has been company practice for over 5 years (M6:10). Steele noted that this was done primarily to meet the European requirements (M6:10).

Carlson explained the European Union (EU) requirements for machine tool safety (M6:10). For a machine to be sold in the EU market, it has to meet hundreds of requirements including those addressing noise, mist control and guarding (M6:10). If a manufacturer does not meet the requirements, the manufacturer can be forced to take it out of Europe and not sell any others for a given period of time as a penalty (M6:10). Carlson noted that there are EU machine tool safety requirements on the machine tool manufacturer and safety in the workplace requirements on the user of the machine (M6:10). McCarthy noted that the EU requirements prompt tool makers and users to work together (M6:10). McCarthy noted that an agreement to meet European requirements was made by manufacturers (M6:10). McCarthy explained that the European divisions of the large US machine tool companies do this work and that eventually, conformity among EU, ANSI and OSHA may occur worldwide (M6:10).

Customers want the machine to have any required safety equipment and do not want to spend any extra money for total enclosure unless it is required, according to Stevens (M6:9). Cross-Huller builds to 5.0 mg/m3 unless it is specified otherwise (M6:16). McCarthy stated that customers want the machine safe, quiet, clean and the floor dry (M6:9). McCarthy explained the Big 3 have requirements of 80 dBA, dry floor and 0.5 mg/m3, beyond what is required by OSHA noted Stevens (M6:9,19). Only ventilated, enclosed machines meet these requirements according to McCarthy (M6:9). The next tier companies also require 0.5 mg/m3, according to McCarthy (M6:16). Below this tier, companies may not request enclosures but get them anyway (M6:16). According to Kushner, all-new equipment for his mid size facilities arrives enclosed (M6:33). Smaller companies are starting to ask for total enclosure or dry floor according to McCarthy (M6:16). He stated that all transfer lines and CNC machines have enclosures (M6:16). Other machines have standard safety guarding and have a dry floor guarding mist enclosure package that can be included and is required by the Big 3 (M6:16). The Big 3 are pressing their suppliers to have enclosures (M6:16). Fay noted that if his customer wants him to meet a regulatory standard or a voluntary standard, he can design to that specification (M6:18). Having a supplier meet different needs in different plant environments is difficult, according to Hedley (M6:19). Most of this is done by specifications (M6:16). Woody noted that today most machines come into a new plant or into major retrofits of existing plants, are enclosed (M6:9). Woody noted this is regardless of the size company involved (M6:9). Hedley noted that half of the machines his company encloses are directly for the manufacturer of the machine; the other half are requests from customers for enclosure (M6:10). According to McCarthy, machine tool companies and the customers and their suppliers are working together to figure out how to effectively reduce the mist (M6:16).

Burch was concerned if machines conforming to a specific voluntary standard may be sold without enclosures (M6:10). McCarthy clarified that multiple standards may apply for one type of machine (M6:10). Carlson explained that it would not be good to sell a machine without an enclosure due to noise and mist concerns and that one enclosure could address each of these problems (M6:10). Carlson noted that the ANSI B-1113 standard for screw machines was done in 1990 and is due for reaffirmation, revision or revocation (M6:10). Cadson believed a revised version would include enclosure (M6:10).

Stevens explained that many single US machine centers are not totally enclosed but do have side guarding while the majority of transfer lines are totally enclosed (M6:11). Fay noted that some manufacturers sell what are called total enclosures but when he designs the ventilation, he finds that the machine is not adequately enclosed (M6:11).

McCarthy explained for some small machines making very small parts, an enclosure may not be needed (M6:11). Lamb designs the machine so a hood can be dropped on if the output of the machine is increased beyond the original design (M6:11). McCarthy noted that when his company does a class B re-tool, tearing the machine completely down and completely rebuilding it, the guarding is redesigned for total enclosure (M6:11). He explained that a class A re-tool which includes rebuilding a couple of stations from a machine, you cannot enclose just those stations, so they build to the as-built standard (M6:11). McCarthy highlighted for a class A re-tool, the builder has to consider consistency within a machine and the knowledge and experience of the operator (M6:11).

Design for enclosures has to include air flow, and a distribution of pick up points across the enclosure, according to Woody (M6:12-13). Fay also noted MWF movement and in-draft and baffles (M6:13). Fay cited an in-draft of about 200 FPM to control mist (M6:13).

Most of the representatives of companies that provide enclosures noted that 75-95% of their enclosures are custom made (M6:7). McCarthy explained that Lamb Technicon has four sets of standard enclosures that will fit about 85% of their machines but each standard enclosure is customized to fit the given situation (M6:7). According to Carlson, about 80% of machine tools sold by AMT members are for production and 20% used for upkeep and repair of other machines (M6:7).

Testing procedures to determine that a machine tool enclosure is effective were discussed in light of the NIOSH/OSHA Asphalt Paving Agreement (M6:12-13). Hedley explained that he did, e.g. noise testing, before and after enclosure on a retrofit (M6:12). McCarthy explained for stand alone machines, the customer's industrial hygienist could come to the manufacturer's plant and measure the output (M6:12). For transfer lines, the flume complicates the measurement of mist and the design of effective enclosure according to McCarthy (M6:12). McCarthy explained different variables that could affect a test such as the volume of coolant used (M6:13). O'Brien opined that the company could run the test at the specified MWF rate (M6:13). McCarthy was concerned that the test could not be applied in real situations and that there is not any standard number of stations in a transfer line, so how could this be tested (M6:13). Stevens was concerned about a machine passing a test today but after three months of operation may not, because of how the customer uses the machine (M6:13). Stevens cautioned that it would be difficult to develop a specification because where you test the machine and what machines are operating nearby can influence the outcome (M6:13).

Howell agreed with Burch that the variety of operations and conditions preclude the use of any standard test (M6:14). Lick noted the difficulties of trying to develop a test method in the ANSI committee (M6:14). Lick explained that a direct reading meter could be used but that shop trials and what occurs in the plant are not the same (M6:14). Woody explained that there are different types of enclosures with varied openings and structures complicating the testing (M6:14).

McCarthy explained that he did not know of any machine tool manufacturer in the US who was set up to test the ventilation system, so the work is done on the plant floor after installation (M6:14). The customer does the testing along with the coolant supplier (M6:14). McCarthy noted that design teams like Giffels help put the whole operation together (M6:14). Burch noted that a tool will not be doing just one thing for the rest of its work life (M6:13). Many shops have a wide variety of jobs done by the same machine tool (M6:14).

Steele noted that air conditioning improves the accuracies of the cuts made in machining but does not affect tool life (M6:15). McCarthy clarified that by keeping a constant temperature in a plant, the machine will be more consistently accurate (M6:15). McCarthy noted that there will be less maintenance and less misting (M6:15).


3.4.5 Additional Information about Enclosure Technology from the NIOSH Criteria Document

Many of the same topics addressed by O'Brien, Johnston and Hands are covered in section 9.33 of the NIOSH Criteria Document (NIOSH,1998). NIOSH acknowledges situations where enclosure may not be possible (NIOSH,1998). The document stresses the use of established criteria such as the ANSI Mist Control document and the ACGIH Industrial Ventilation, A Manual of Recommended Practice, 1995 (NIOSH, 1998). NIOSH notes the limitations of recirculation and the criteria outlined in the NIOSH document on Recirculation of Industrial Exhaust Air (1978).

3.4.6 Additional Resources Related to Enclosure Technology

Howell noted the ASTM E1972 Practice for Minimizing Aerosols in the Wet Metal Removal Environment (M4:5). Many committee members and speakers cited the ANSI B11 Document on Mist Control. Others noted that the ACGIH ventilation manual should be consulted for many design criteria. The ORC Management of the Metal Removal Fluid Environment (1999) addresses issues related to enclosure technology and a wide range of ancillary issues. The Ford Motor Company Economic Report provides additional information on exposures by plant (Henry 1998). Articles by Leith address mist control and vaporization (Leith,1996a; Leith, 1996b). Additional references found in Attachment #6.

3.4.7 Research and Experiences Related to Other Controls

Lusniak and Teitelbaum highlighted the traditional control approaches of substitution, elimination, personal protective equipment, training, housekeeping, materials handling, administrative control and ventilation (M2:13-14, 20). Adams noted that protective clothing can help prevent dermatitis but that gloves often interfere with tasks (M2:2). Stein noted the difficulty of separating out the controls for dermatitis from respiratory effects (M5:29). For dermatitis prevention, the systems work group added: automation, fluid maintenance, decreasing contact, improving hygiene, and proper use of soaps (M8:5).

Lusniak stressed the importance of hand washing with mild soaps (M2:14). He recommended several washings with mild soaps during the day, and an end of the day washing with a more aggressive soap (M2:14). He urged careful attention to the MSDSs for the soaps used (M2:14). Lusniak suggested pat drying with a soft cloth and the avoidance of rubbing (M2:14). Wiping without diluting the MWFs, as with a shop rag, will often do more harm than good because the MWFs are mashed into the skin and the rag is saturated (M2:14). Kushner explained that his company have made a science of handwashing (M2:14).

Lusniak noted that barrier agents do not work well with MWFs but could act as a moisturizer (M2:14). Kushner explained that his company provides skin lotion throughout the plant (M2:15). Lusniak noted that lotion needs to be free from contaminants and that some workers are allergic to lanolin (M2:15).

Shortell explained the need for ways to reduce skin contact during insert changes (M8:5). Inserts are the parts of the cutting tool that wears out and have to be replaced frequently (M8:5). Burch noted that Valenite, the mid size plant visited by work groups, made inserts (M8:5). Shortell explained ways of reducing contact such as using valves and directing MWF tubes away from the insert (M8:5). Depending on the machining process, these recommendations may be easy or difficult to accomplish (M8:5).

Mist suppression was discussed by the committee (M8:4). O'Brien noted the Lubrizol/Wayne State work that shows anti-misting additives can reduce the mist levels by a factor of two (M2:16). Lick noted that these compounds do not always work and may be maintenance intensive (M2:16).

Watt cited 40-50% reduction in mist in some Chrysler work (M3:8). For soluble fluids, the current suppressants are not shear stable and they degrade with each cycle through the system (Watt, 1998). Constant addition of suppressant is required and the suppressant is expensive but the price is dropping (Watt, 1998).

d'Arcy stated that GM had mixed results with these compounds (M3:11). There was concern expressed about adding more problems to the fluids (M8:4). Additional information on mist suppression is found in the proceedings of the two Symposia on MWFs ( M8:4; AAMA, 1996,1998).

The system work group thought respiratory protection was technically feasible but not practically feasible (M8:5). Any use of respirators would have to follow the OSHA standard on respiratory protection (M8:4). Anderson opined that respiratory protection would not be a primary control, but could be a secondary one, and questioned what would trigger this need (M8:4).

Wegman noted the importance of reducing the amount of MWF used (M8:11). A systematic approach is essential, according to Fay and practices such as using compressed air should be avoided (M6:18).

Mirer explained that shutting down the fluid circulation and maybe the flume when no machining is occurring may reduce mist (M3:11). Mirer emphasized the importance of a well functioning general ventilation system, restoring enclosures, cleaning and repairing duct work, checking air filters and thought 90% of the problem could be solved without anything new (M2:12). O'Brien noted that fluid management must come first and containment and ventilation may eliminate some of the peak exposures(M5:16).

The NIOSH Criteria Document cites the potential need for personal protective equipment (NIOSH, 1998). Protection against punctures, cuts, abrasions, splash and skin contact is noted (NIOSH, 1998). Proper selection and use criteria are defined (NIOSH, 1998).

3.5 CONCERNS AND LIMITATIONS

3.5.1 Size of Business

Burt studied data on companies of all different sizes within 6 major SIC codes (M7:24). There are approximately 3.1 million machines with about 1.3 million used by the smallest businesses of 1-19 employees (M7:24). SIC code 35 contains 43% of the machines (M7:24).

Burch noted that systems management is essential in small business, especially with water soluble fluids (M4:8). He explained that many small business avoid these types of fluids (M4;8).

Howell commented that a systems management approach to fluid management is good and works in both large and small shops, no matter what type of fluid is used (M2:16). The ways to solve problems may be different (M2:16). He cited the need for systems management in the small shops the work groups visited (M4:8). He noted that a stewardship program would reduce situations such as the one observed in a visited facility in which a fluid salesman gave incorrect information to make a sale (M4:4).

Lantz also thought the best way to address small business was through their supplier's product stewardship program (M8:12). Burch noted that small business needs answers quickly, especially in a crisis situation (M8:12). A good relationship with the fluid supplier may be the way to address crises.

Burch was concerned about representation of small business on the machine tool panel (M6:7). All of the companies represented on the machine tool panel except Tamer Industries primarily served the auto industry (M6:7).

Off the shelf, commercially available solutions are needed for small business, according to O'Brien (M6:39). Mirer noted that if each company fully applied good specifications, exposures would be less than 0.5 mg/m3 (M6:40).

Piacitelli thought it would be difficult for some of the shops in the Small Business Study to comply with 0.5 mg/m3 (M7:4). Wegman noted that Piacitelli's data could not determine the difficulty of compliance (M7:4).

Woody noted that small and medium size businesses are handicapped on the logistics side since they don't have the resources to gather information needed to make a modification (M6:17). Larger companies have internal staffs to guide their decision making (M6:17). Carlson agreed that smaller plants probably have lower exposures (M6:17). Carlson noted that small plants have lower speeds, fewer machines and you see less mist (M6:17).

Howell agreed with O'Brien and White that the biggest burden would fall on the mid sized business (M6:40).

Rossmoore noted that the large central systems are the ones that are difficult to control (M5:24). Mirer believed that controlling a big aluminum transfer line presents more of a challenge than individual machines (M3:16). Lick and Shortell viewed that the larger industries have a tougher time with feasibility because they have higher pressures and volumes of MWFs (M4:7).

Howell noted that what PEL is chosen defines the burden for small business (M8:17). Burch did not think medical surveillance could work for small business without resources due to the infrastructure needed (M8:15). He urged the group to make any action do-able so small business can take care of employees with their limited resources (M8:16).

3.5.2 Determining the Effectiveness of Systems or Fluid Management

O'Brien was concerned how to define what a good fluid management program is (M5:16; M7:21). White and Howell stated it is easier to state what good MWF management is, than what is inadequate (M6:27). Burch opined that if the MWF did not go bad, you had a good program (M6:27).

Sheehan cited the indicators before a system failed and Howell explained that good management prevented excursions out of normal operating range (M6:27). Biocide use and the potential of endotoxin build up are reduced with good management, according to Howell and Sheehan (M6:27).

Lick stated before systems management was used at Ford, 95% of their exposures were from 1 to 200 mg/m3 and after implementation, 95% were below 1 mg/m3 (M2:17). Case studies can be used to demonstrate effectiveness according to Lick (M2:17).

The extent of MWF management in the studies done at GM is a problem, according to Howell (M6:21). As a result, it is difficult to interpret the influence of fluid management that was in effect at the time on health.

Wegman noted the criteria for a fluid management program could work with medical surveillance (M8:15). Benchmarks are needed according to Wegman and d'Arcy (M8:16). Having the fluid management integrate with medical surveillance could make the surveillance less burdensome, according to Howell (M8:17).

3.5.3 Other Concerns about Systems Management

O'Brien noted that industrial hygienists do not know anything about fluid management (M7:21). Lick disagreed and believed that industrial hygienists can take advantage of short courses and other resources (M7:22). O'Brien explained that people at the plant can be trained and based on his observations at Valenite, be very motivated (M7:21).

The systems group noted that product stewardship has to be integrated into a systems approach (M8:4). Mirer cited incidents where even with product stewardship and an external MWF manager, the user did not follow the manager's suggestions (M8:4). He noted some of the litigation involved with these situations (M8:4). Sheehan explained the group's concern that there was product stewardship and "good" product stewardship (M8:4).

Howell commented that product stewardship is part of systems management (M8:4). He noted that integrating the user and supplier's programs provides a more successful program (M8:4). He cautioned that there will always be human error (M8:4). Shortell explained that accountability by the manufacturer or blender or vendor is necessary (M8:4). Teitelbaum was concerned about the limited information on MSDSs and urged fluid formulators to provide information about allergenicity (M2:20). Teitelbaum questioned if product stewardship has been shown to reduce injury and or illness (M7:32; M8:4,11).

The committee questioned the advice given in some situations by formulators. Goon explained the complexity of the formulator, distributor, user relationships (M5:25). He noted that fluid formulators often provide technical assistance to customers (M5:25). Distributors, not formulators, usually sell to small and medium size companies (M5:25). This complicates the provision of technical advice (M5:25). Some company managers do not want to take advice when a system goes bad, according to Mirer (M5:25). As a result they misuse biocide (M5:25).

The smoking issue was raised related to systems management. If eating and drinking are not recommended in MWF areas, smoking should not be allowed in these areas as well (M8:27).

3.5.4 Problems with Full Enclosures

Hedley explained that the enclosure should not affect the life of the machine (M6:14). Hedley noted that acceptance by the operator and maintenance can be a problem (M6:14). His firm tries to inform the operator upfront so the operator is not surprised by the enclosure (M6:14). Hedley recommended getting the operator and maintenance people involved in the design (M6:14). Guy noted complaints from workers about interlocks delaying work and full enclosures complicating troubleshooting (M3:7).

Stevens explained that heat can build up in total enclosures, potentially affecting the part and upsetting the gauging people on a line (M6:14). He noted one situation without a collector that became so pressurized that the temperature was 20 degrees warmer inside than outside the enclosure (M6:14). A letter to a trade group indicated a fire in a complete enclosure (PMPA, 1999).

Some total enclosure designs can capture the chips and bring them into the ductwork, according to Stevens (M6:14). Stevens explained that access can be difficult with certain designs and to put the system back together after maintenance is critical to maintain a dry floor and mist control (M6:14).

Shortell noted that most new machines were fully enclosed and many of these were turning machines, the biggest mist producers (M4:6). He noted that companies buy new machines to compete for contracts, so there are other incentives for having the new machines (M4:6).

3.5.5 Problems with Retrofit Enclosures

Lick cited the Hands' study which indicated for OEM enclosures, there was less variability as compared to retrofits (M7:5). Johnston noted that he can routinely meet 0.5 mg/m3 with OEM enclosures but not with retrofit (M3:9). Lick did not think retrofits could do the job (M7:5).

O'Brien disagreed with Lick and believed that retrofit technology would work (M2:16). O'Brien noted that off the shelf retrofits can be used in small business and will have the added advantage of noise reduction (M2:16). Mirer noted that individual machines could be successfully retrofitted and that he had some case studies on this (M8:4).

The systems group defined refurbished or remanufactured equipment as second hand machine tools that have been retooled (M8:5). The group thought that a stripped down and reconstructed machine with a full enclosure should work (M8:5). Burch clarified that some machine tool rebuilding is not this extensive (M8:5). He noted that some automatic machines could be totally enclosed with off the shelf equipment (M8:5).

Cox explained that there are such a wide range of machines in small businesses, that builders would have a difficult time building retrofit kits that work (M4:6). He was concerned about product liability, noting that manufacturers would rather sell a new machine and enclosure than retrofit an old one (M4:6; M8:5).

The retrofit market is not attractive to companies producing enclosures, according to Hedley (M6:8). Retrofits require intensive engineering and time for limited quantities of product (M6:8). Companies would rather enclose a new machine and new enclosures are better accepted by employees (M6:8). Retrofitting requires enclosure while the machine is still in production, according to Fay (M6:12). Warranties on retrofits are a problem according to the machine tool panel (M6:12).

3.5.6 Other Concerns about Enclosures

McCarthy expressed his concern that the same people we are protecting take off the guards and do not replace them (M6:14). McCarthy explained how some of the guards get thrown away, and are only replaced after an OSHA inspection (M6:14). Burch thought the problems with retrofits may be due to operators overcoming the barrier (M2:16). Watt had this concern as well (M3:8).

McCarthy stressed that enclosures have to be user friendly (M6:14). There are different degrees of user friendly and the most difficult worker to deal with is one who has worked a long time and does not want to bother with the guard (M6:14). McCarthy noted that the newer employees are more used to working with total enclosures and cooperate better (M6:14).

McCarthy noted that Lamb uses rollers, hinges and sliding panels for their transfer line enclosures and these are not taken off (M6:14). Steele agreed with McCarthy that any panel designed to come off will be taken off and may not be replaced (M6:14). Steele recommended sliding doors, hinged doors that lift up or come out of an adjoining lift (M6:14).

3.5.7 Recirculation

O'Brien explained that recirculation of air back into the plant is used in some facilities with MWFs due to concerns about energy conservation costs and avoidance of EPA volatile organic compound (VOC) emission limits (M3:1). He highlighted the disadvantages of recirculation including the need for high efficiency filtration and the problems of increased relative humidity, microbial growth on filters and MWF vapor production from the filters (M3:1-2).

Guy did not view recirculation as a problem since 95% outside air is brought into his plant (M3:7). Kushner and Burke noted that some of their mid sized plants recirculate air (M6:33).

O'Brien noted the leak in a HEPA filter at the plant the work groups visited and was concerned about unmonitored recirculation (M3:15). O'Brien suggested a back up HEPA or use of a direct reading aerosol monitor to detect filter failures because a simple magnehelic gauge would not pick up a leak (M3:15). Lick did not think an additional HEPA was technologically feasible (M3:15).

Woody recommended against using recirculation in almost any plant, and that air brought from the enclosures be sent outside (M6:15). He noted that any direct fired heating plants have to bring in make up air and typically this volume is greater than any leaving the plant from enclosures (M6:15). Woody noted that the economics of heating or cooling this air show no penalty (M6:15).

Lick noted that variables such as air volumes, types of enclosures and plant age affect the decision to recirculate (M6:15). Lick noted that location in an EPA non-attainment zone also influences the choice to recirculate (M3:5; 6:15). He agreed with Woody that plants might be cleaner without recirculation, but in some instances recirculation may be needed (M6:15).

The systems work group noted an additional concem about fine particles with recirculation (M8:4). If recirculation is used, a 3 stage collector with HEPA filter, perfectly run and monitored with no defects and a bypass system should be used (M8:4). Some of these same criteria could be used before sending the air outside (M8:4). Mirer agreed with these recommendations (M8:4). Howell noted that the ORC document provides some general information about these issues (M8:4).

3.5.8 Vapor Production

Vapor generation from mist collectors into the work environment was noted by Leith who stated that the collectors can emit vapors even when the MWF using process is not operating (M3:4). Vapor output can be in the mg/m3 range according to Leith (M3:4).

Lick thought that if the total mist is below 0.05 mg/m3, the vapor issue is also addressed (M3:4). O'Brien suggested not operating the mist collector when the process is down (M3:5).

Kushner noted that he showed very little vapor problem when he monitored processes in his plant (M3:5).

3.5.9 Other Concerns about Ventilation

Mirer noted that consideration of criteria for the general ventilation system is important (M8:4). Lick and Howell were concerned with the lack of ventilation in the small shops the work groups visited (M4:6). Lick cited other reasons such as forklift use for improving general ventilation (M4:6). Mirer agreed that the ventilation needed to be improved and air blowoffs avoided (M4:7).

3.5.10 Limitations of Studies

Piacitelli explained that NIOSH selected out the dirtiest SIC codes to try to find the worst shops to sample (M4:3). Newman was concerned that only a third of eligible shops participated (M4:3).

Burch indicated that the OSHA Database is biased because the plants in it had an unrequested OSHA inspection due to an employee complaint or other reason (M4:2). White explained that the OSHA dataset may not be biased as indicated by studies that have shown OSHA inspections driven by complaints do not find any more violations than random inspections (M4:2).

Background levels found in the studies were a concern. Typical assembly areas according to Mirer, citing Eisen's study, are 0.1 mg/m3 (M2:12). Burch was concerned about outside levels and Mirer noted that they were in the 0.03 mg/m3 range (M2:12). Mirer noted that if the background is 0.4 mg/m3, and the operator's exposure is 0.6 mg/m3, 0.4 mg/m3 is the best that can be achieved (M7:5).

3.5.11 Time and Resource Factors

Members were concerned about the time it would take for new technology to be available. According to Lick and Carlson, the average age of a US machine tool is 29 years (M6:7). Burch noted that some of his member companies still use World War II vintage machines while others need very new machines to meet customer demands (M6:8). Burt explained that 75% of establishments own some machines less than 5 years old, 7% have ones 6-10 years old and 95% have at least one machine older than 11 years old (M7:24). Machine replacement is slow and many old machines are still in these workplaces (M7:24). Teitelbaum noted the age of the machines used and explained that it would be a long time before new machines would replace old ones (M7:5).

The time line is long even when a company decides to order a new machine. McCarthy explained that Lamb Technicon could deliver an off the shelf CNC machine in 28 days while a transfer line could take from 40-62 weeks depending on the completeness of information provided by the buyer (M6:9). Steele noted that 12 months is a good number for special machine groups and Stevens agreed (M6:9). Substantial backlogs of orders were noted by all machine tool companies (M6:9).

Lick noted the time it takes to reduce exposure and that OEMs are easier than retrofits (M3:16). He cited the Sharonville plant's efforts as 30% complete and it has taken 10 years to accomplish (M3:16).

Carlson explained that the real problem was skilled individuals to manufacture machine tools; there is a shortage of machinists (M6:9). Use of machines was discussed by Burch and Cox, each noting that newer machines are used less early in their work life (M7:4). As more applications evolve, new machines have more work (M7:4). More information on time factors is provided in Chapter Four.

3.5.12 Trends in Machining

Broad trends in machining can affect how technologically feasible a control method is. Burch stated in small business, machines are purchased to meet customer demands (M6:8). Lick explained that the auto industry is purchasing machines to provide better accuracy, higher machining speeds and improved production (M6:8). McCarthy agreed that in the US, faster cutting is the trend with a part cut every 17-18 seconds (M6:8). In Europe, due to concerns about mist and noise, the trend is reversed with lower speeds and fluid pressures (M6:8).

Kushner noted a trend away from metal removal since the metal is a waste to be reprocessed (M6:8). Some companies are using more hot and cold forging instead of cutting, according to Kushner (M6:8-9).

3.5.13 Other Concerns

Burch stated that regulating contact out of some jobs would be impossible (M2:20). He questioned the potential action of a small shop having to change fluids if someone gets dermatitis (M2:20). He was concerned about the role of the ADA (M2:20).

Shortell was concerned about 100,000 small shops having to hire industrial hygienists (M7:22). He hoped that shop people could be trained to reduce this limitation (M7:22).

The issue of how controls would change if cancer was the major driver for regulation was discussed. Ventilation would be more important for carcinogens, according to Mirer (M7:11). Since he viewed any standard as feasibility driven, the issue of cancer would not affect the ultimate air concentration used (M7:11). Kushner noted that labeling, providing work clothes and waste management would change based on carcinogenicity (M7:11).

The systems work group urged integration of any recordkeeping with other existing systems and maintenance of historical tracking of data (M8:5). Mirer suggested having MWF maintenance records available to workers (M8:5). Audience member Gary Farwick noted that most of the time these types of records are posted to spur employees and the organization to do a better job (M8:5).Howell agreed with Farwick and Mirer that they should be available but there was not any current legal requirement (M8:5).

3.6 LINKAGE OF DISCUSSIONS TO OSHA ACTION

3.6.1 Systems Management

Infante was concerned on how OSHA would show that it significantly reduced a significant risk without a PEL (M2:17). White explained that data on injuries and illnesses could be used to show a reduction in these after implementation of a systems management program (M2:17). He noted that something like a VPP site program could be used (M2:17).

Lick explained that the pattern of respiratory disease presented by Reeve followed the extent of the fluid management in some Ford plants, and not others (M6:3). Lick noted that even with an exposure limit of 0.5 mg/m3, if the fluid is not managed, problems will develop (M2:15). Systems management will do a better job of controlling HP and respiratory irritation than a PEL, stated Lick and White (M2:16,17).

Howell noted that Perry's data showing a risk at 0.1 mg/m3 indicate other variables than airborne exposure at work (M6:23). Management of fluids will reduce occurrences of at least the irritant dermatitis, according to Howell (M2:20). He noted that without systems management, reducing exposure to less than 0.5 mg/m3 is unlikely to further reduce non-cancer respiratory disease (M5:16).

McGee stated a standard is needed because not all users are managing fluids the way they should (M6:41). Management's attitude about MWF management varied from plant to plant within the same corporation (M6:41).

O'Brien explained that NIOSH's recommendation included a comprehensive safety and health plan of which fluid management and a systems approach are components (M2:16). Systems management would address dermatitis and asthma, according to O'Brien (M13).

Stein explained that early NIOSH and OSHA recommendations about machining operations included components of what is today called systems management (M5:29). Recommendations such as daily monitoring of pH, bacterial counts, daily machine cleaning, exhaust systems, oil collectors and clean shop rags were addressed (M5:29).

3.6.2 Enclosures/Other controls

NIOSH based its recommendations on respiratory effects and believes that 0.4 mg/m3 thoracic particulate or 0.5 mg/m3 "old total particulate" is technologically feasible, according to Fine (M2:1).

According to Howell, voluntary or consensus guidelines with a target exposure level appeals to many because it covers so many factors that can affect employee health (M2:17). Howell noted it may be important to recommend to the ACGIH that an "S" designation be given to MWFs for its TLV (M8:26).

Exhaust ventilation of an enclosed machine is needed to get consistently below 0.5 mg/m3, according to Lick (M2:15). Lick noted that dermatitis just about goes away when you keep everything in the machine (M2:15). He explained that Ford physicians are not seeing dermatitis (M2:21). Wegman noted that there will be background levels of dermatitis in plants not caused by MWFs (M2:21).

Mirer noted that controlling one machine may result in reducing levels for that operator as well as others due to cross contamination (M3:11). He viewed that mean exposures of 0.25 mg/m3 were clearly achievable (M3:11). Mirer cited a NIOSH HHE report and noted that in a foundry, all the air samples were below the NIOSH REL and this points to the feasibility of 0.5 mg/m3 (M6:37).

Machine tool panel members Carlson, Hedley, Stevens and McCarthy believed it was technically feasible to achieve 0.5 mg/m3 (M6:16-17). They stated concerns about cost, liability and maintainability of the enclosures and mist control equipment (M6:16-17). McCarthy thought it may be better to grandfather in older machines (M6:17). A high percentage of machines are older than 10 years, according to the panel (M6:17). McCarthy, Fay and Steele thought it would be difficult for older machines in smaller shops to meet 0.5 mg/m3 (M6:17). Carlson thought that requiring an enclosure on machines that do not generate much mist would be an unnecessary burden (M6:18).

Burke noted that many of his plants have exposures between 1.0 and 2.0 mg/m3 (M6:28-29). Using area samples, the majority of his plants were below the NIOSH REL (M6:29). He noted that the open grinders his company uses generate a lot of mist and are difficult to enclose (M6:29). It would be tough to have the grinders comply with 0.5 mg/m3 (M6:34).

Lick was concerned about the time it would take to comply (M3:16). Lick noted that the conclusion that everyone is already at 0.5 mg/m3 is erroneous, and most companies were between 1.0 to 2.0 mg/m3 moving toward 0.5 mg/m3 (M6:34). He thought it would take a long time to achieve control across all industries (M6:41).

Wegman noted that Piacitelli's data could not determine the difficulty of compliance (M7:4). Wegman thought the difference between mean values found in the Small Business Study and individual samples was striking (M7:4). Howell noted that based on the current approach to a 6b standard, citing for one exposure, many of the plants in the small business study would be affected (M7:4).

The Systems Work Group cited the discussion of d'Arcy, Johnston, Kramer, Hartwig, Watt, Hands and the NIOSH Small Business Study (M8:3). The group viewed it was technically feasible with new equipment to reduce exposure significantly below what it is today (M7:3). It would not be easy to do this for transfer lines (M:3). New equipment enclosures are more consistent reducing exposure than are retrofits, although less is known on retrofit use on individual machines (M8:3).

Mirer noted that OSHA cannot establish a standard that everyone has already met (M7:5). He explained that if the geometric mean of exposures in a plant was 0.5 mg/m3, 5% of samples would be over 1.0 mg/m3 (M7:5). Not every machine has to be replaced to meet the 0.5 mg/m3 value according to Mirer (M6:8). Mirer noted that if each company fully applied good specifications, exposures would be less than 0.5 mg/m3 (M6:40).

3.7 COMMITTEE DECISIONS AND RATIONALE

The majority (12) viewed that the recommended PEL was technically feasible (M9:30-31). Day, Teitelbaum, Mirer and O'Brien cited their own experiences, presentations before the committee, site visits, the machine tool builders discussion and data provided by industry as a basis for this decision (M9:30). The downward trend in exposures with time, the evaluation of controls study done by Hands et al, and the NIOSH Small Business Study were also noted by O'Brien as a rationale (M9:30). O'Brien and Mirer urged more effective use of general ventilation to achieve the targeted PEL (M9:30-31). O'Brien noted that straight fluids are more difficult to control and opined that anti-mist additives may be helpful to control exposure in small business (M9:31).

The minority (Howell) opinion was that although the PEL could be achieved with new equipment, it could not be with old, existing equipment (M9:31). A discussion of the limits of retrofits cited the Hands et al study on transfer lines (M9:30-31). Sheehan noted that retrofits may work better on individual machines than on transfer lines, and Lick explained that retrofits are difficult to do well (M9:30, 31).

Burch focused on the technical feasibility of measuring exposures at the PEL and thought it was feasible (M9:30). He did not have enough information to determine the feasibility of a PEL (correction noted at tenth meeting). He questioned the technical feasibility of measuring the action level (M9:30). Cox could not separate technical feasibility from economic feasibility, noting that some companies would be more able than others to comply based on their financial condition (M9:30).

The majority (12) explained that medical surveillance, as defined by the best practices document prepared by the committee, was technically feasible (M9:30-31). Newman based this decision on his own experience developing programs for businesses (M9:30). Sheehan cited the long track record for these types of tests (M9:30). McGee urged training of workers about medical surveillance (M9:31). Alternate member, Shortell, noted that medical surveillance may present some problems for small businesses but that our recommendation should be crafted with this in mind (M9:31).

The minority (Burch, Cox, Howell) opinion on the technical feasibility of medical surveillance was that the program specified in the best practices document prepared by the committee was not technically feasible (M9:30-31).

All members (15) viewed that systems management was technically feasible (M9:30-31). Members cited the presentations, site visits and their own experiences as contributing to this decision (M9:30-31).