Metalworking Fluid Mist—Strategies to Reduce Exposure: A Comparison of New and Old Transmission Case Transfer Lines

Abstract

Three studies were performed to assess the effectiveness of various techniques to control metalworking fluid (MWF) mist. The studies consisted of a detailed main study that determined the effect of degree of enclosure on personal exposures and area concentrations of MWF mist on two machining transfer lines. One ancillary study was conducted to determine the effect of shutting off MWF delivery during down time; the second ancillary study investigated the effectiveness of improved retrofitted enclosure. In the main study, the two operations were identical except for degree of enclosure. Personal and area sampling results for the new line were about half those found in the old line. Measurements at the new operation exhibited significantly less variability. Personal exposures and area concentrations were significantly less at the new operation than at the older, less enclosed operation, demonstrating that the total enclosure in the new operation provides better and more consistent control of the mist. The first ancillary study was conducted to determine if shutting off MWF delivery to the parts being machined reduced area MWF mist concentration during downtime at a partially enclosed transfer machining line. A significant reduction in concentration of 80% was measured with machining off/MWF off. Mist concentrations measured with machining off/MWF on were not significantly different from mist levels measured during machining on/MWF on. The second ancillary study investigated the reduction of mist concentration achieved through improved enclosure of an existing set of machines. Area mist concentrations were measured at a machining operation before and after the installation of an improved enclosure. Area mist concentrations were reduced by 87% with the improved enclosure.

Determinants of Exposure to Metalworking Fluid Aerosols: A Literature Review and Analysis of Reported Measurements

“…Originally equipped machines (OEMs) were reported to be associated with significantly lower exposure levels than retrofitted enclosures or machines with few or no enclosures (median 5 0.21 versus 0.45 and 0.48 mg m À3 , respectively, P , 0.05) (Hands et al, 1996). This finding was supported by studies reporting differences before and after upgrades (GM 5 2.24 versus 0.19 mg m À3 , respectively, P , 0.0001), on an old versus new transfer line (0.49 versus 0.26 mg m À3 , respectively, P 5 0.003) (Sheehan and Hands, 2007) and on machines using old versus new technology (Dasch et al, 2005). Another study found no statistically significant effect of splash guards on exposure levels (Piacitelli et al, 2001).…”

“…Thus, the technology was more effective for larger particles than for smaller particles (Dasch et al, 2005). Although an effect was reported for various types of engineering controls on total aerosol exposure levels (Hands et al, 1996;Piacitelli et al, 2001;Dasch et al, 2005;Sheehan and Hands, 2007), the number of aerosol exposure measurements with same (or similar) engineering control type in these studies was insufficient to allow us to conduct a meaningful analysis.…”

New evidence on the health hazards and control of metalworking fluids since completion of the OSHA advisory committee report

“…Many of these report prevailing exposures less than 0.5 mg/M 3 , frequently at 0.25 mg/M 3 and below Thornburg, 2000;Yacher et al, 2000;Piacitelli et al, 2001;Rosenthal and Yeagy, 2001;Dasch et al, 2002;Leith et al, 2003;Stear, 2003;Ross et al, 2004;Raynor et al, 2005]. A recent study directly addressed the feasibility and practicality of retrofitting equipment for controlling exposures generated by existing high production, linear transfer lines [Sheehan and Hands, 2007].…”

A multi-criteria decision method for sustainability assessment of the use phase of machine tool systems

“…The control of the occupational exposures and health effects and exposure assessment has been intensively studied [3][4][5][6][7]. Moreover, several organizations such as US Occupational Safety and Health Administration, US National Institute for Occupational Safety and Health, and US Environmental Protection Agency are very active in promoting health and safety guidance through substantial standards related to occupational exposure to metalworking fluids and aerosols.…”