Swelling of Four Glove Materials Challenged by Six Metalworking Fluids Wenhai Xu Æ Shane S. Que Hee Received: 6 March 2007 / Published online: 7 August 2007 Ó Springer Science+Business Media, LLC 2007 Abstract The performance of protective gloves against metalworking fluids (MWFs) has rarely been studied because of the difficult chemical analysis associated with complex MWFs. In the present study, glove swelling was used as a screening parameter of glove compatibility after challenge of the outer surfaces of chloroprene, latex, nitrile, and vinyl disposable gloves by six MWF concen- trates for 2 hours in an ASTM F-739-type permeation cell without collection medium. Swelling relative to original thickness was up to 39% for latex, 7.6% for chloroprene, and 3.5% for nitrile. Shrinking up to 9.3% occurred for vinyl. Chloroprene and latex did not swell significantly for the semisynthetic and synthetic MWFs. Vinyl, previously not tested, was a good candidate for MWFs other than the soluble oil type. Although nitrile was recommended by the National Institute for the Occupational Safety and Health (NIOSH) for all types of MWFs, its swelling after 2-hour challenge was significant with Student t-tests for the sol- uble oil, synthetic, and semisynthetic MWFs. Glove swelling can be used as a screening chemical degradation method for mixtures such as MWFs with difficult chemical analysis. Further studies need to be conducted on the relationship between permeation and glove swelling. Introduction Metalworking fluids (MWFs) improve machining perfor- mance and prolong tool life (NIOSH 1998). The National Occupational Exposure Survey in 1981–1982 estimated that 1.2 million workers in the United States were poten- tially exposed to MWFs (NIOSH 1998). Independent lubricant manufacturers in the United States produced 92 million gallons of MWFs in 1990 (McCoy 1994). The estimated use in North America exceeded 2 billion gallons in 2000 (Independent Lubricant Manufacturers Association 2000). The four major types of MWFs are straight oil, soluble oil, semisynthetic, and synthetic (NIOSH 1998). Straight oil MWFs are essentially 100% refined distillates of petroleum (commonly called mineral oils) or of vegetable oils, with bactericides, extreme pressure additives, and other additives. Soluble oil, semisynthetic, and synthetic MWF concentrates are diluted with water before use. They contain up to 85%, 5%–30%, and 0% oil content, respec- tively, with the remainder being water and other additives such as surfactants, fungicides, bactericides, extreme pressure additives, and corrosion inhibitors (Byers 1994; NIOSH 1998; Glaser et al. 2003). The major MWF exposure routes are inhalation and dermal absorption. MWF exposure in the workplace causes respiratory disorders including coughing, chest tightness, and asthma (NIOSH 1998). NIOSH recommends that exposures to MWFs be limited to 0.4 mg/m 3 of air for thoracic particulates, or 0.5 mg/m 3 of air for total partic- ulates as a time-weighted average concentration for up to 10 hours/day during a 40-hour workweek (NIOSH 1998). Before the mid-1970s, MWFs were associated with increased risks of laryngeal, rectal, pancreatic, skin, scrotal, and bladder cancer (NIOSH 1998). ‘‘Severe’’ treatments of W. Xu (&)  S. S. Que Hee Department of Environmental Health Sciences and Center for Occupational and Environmental Health, UCLA School of Public Health, 650 Charles Young Jr. Drive South, Los Angeles, CA 90095-1772, USA e-mail: xuwenhai@ucla.edu 123 Arch Environ Contam Toxicol (2008) 54:1–8 DOI 10.1007/s00244-007-9011-7