Metalworking Fluid Exposures in Small Machine Shops: An Overview

Abstract

Sampling was conducted in 79 small machine shops to assess airborne exposures to metalworking fluids (MWFs). Measured exposures were compared with data from the literature and exposure criteria currently recommended by the National Institute for Occupational Safety and Health and the Occupational Safety and Health Administration MWF Standards Advisory Committee. Sixty-two percent of 942 personal samples collected were less than the recommended exposure limit (REL) of 0.50 mg/m3 for total particulate. However, at least 1 sample exceeded the REL in 61 of the 79 facilities studied; 100% of the samples collected in 10 shops were greater than the REL. Similar trends were found for thoracic particulate exposures where 75% of 238 samples were below the thoracic particulate REL of 0.40 mg/m3. The ratio between thoracic and total particulate for 238 paired samples was 0.55 (r2=0.73). Workers exposed to straight fluids had the highest exposures (GM=0.67 mg/m3) when compared with workers exposed to other classes of MWFs. The highest exposures were measured for grinding and hobbing (GM=0.67 and 0.60 mg/m3, respectively). Measurements using personal impactors indicated that particle size distributions of MWF aerosols had an average mass median aerodynamic diameter of 5.3 microm. Straight oils and soluble fluids tended to be associated with larger particles than were other fluid types; grinding and turning produced the largest particles, whereas hobbing resulted in the smallest. In general, exposures were similar in magnitude and particle size to those previously reported in large automotive plants. Therefore, workers in these small shops may have risks of adverse health effects similar to those demonstrated in the automotive industry.

Occurrence and characterization of culturable bacteria and fungi in metalworking environments

“…This result is consistent with the higher concentrations of fungi and bacteria observed at thread-cutting sites in this survey. According to the study carried out by Piacitelli et al (2001), machines without enclosures are more hazardous in terms of exposure to MWFs than fully or partially enclosed machines. In contrast to workers who perform different tasks throughout the day, thread-cutting workers generally perform their tasks and stand near their machine until the pressing cycle is complete.…”

Optimization of the Design of a Semivolatile Aerosol Dichotomous Sampler

“…For example, the MMADs and GSDs for oil mist were measured between 3.8-8.2 µm and 2.2-3.7, respectively (Woskie et al 1994). In another study, the overall mean MMAD and GSD of oil mist was determined to be 4.9 µm and 2.5, respectively (Piacitelli et al 2001). In these conditions, sampling using SADS will enable effective measurement of both phases with minimal bias.…”

A new measuring method to detect the emissions of metal working fluid mist

“…Flooding, in which the fluid is pumped at low pressure through one or several nozzles directed at the cutting zone, is the most common application method [2]. Application of MWFs during the machining pro- * Corresponding author.…”