Discussion on Metal Working Fluid Exposure Limits


Inhalation of Metal Working Fluid (MWF) mists that exceed OSHA levels can cause irritation of the lungs, throat and nose.  Irritation may affect upper respiratory areas including nose, throat, oral pharynx, lungs, and bronchi.  Symptoms reported after inhalation can include sore throat, red and watery eyes, itchy eyes, runny nose and other cold like symptoms.  These symptoms can in certain instances exacerbate asthma (both acute and chronic), impair lung function and aggravate emphysema.  The degree and severity of irritation and other effects on the respiratory tract is directly proportional to the duration and concentration of exposure.


Currently two OSHA air contaminant permissible exposure limits apply to MWF. They are 5 mg/m3 for an 8-hour time weighted average (TWA) for mineral oil mist, and 15 mg/m3 (8-hour TWA), 29 CFR 1910.1000. No other requirements exist.

The American Conference of Governmental Hygienists (ACGIH) threshold limit value (TLV) for mineral oils is 5 mg/m3 for an 8-hour TWA, and 10 mg/m3 for a 15-minute short-term exposure limit (STEL).



  1. Occupational Safety and Health Administration. Metalworking fluids: safety and health best practices manual. Available at http://www.oshaslc.gov/SLTC/metalworkingfluids/metalworkingfluids_manual.html.


  1. National Institute for Occupational Safety and Health (NIOSH). 1998. Criteria for a Recommended Standard: Occupational Exposure to Metalworking Fluids. DHEW (NIOSH) Publication No. 98-102, NIOSH, Cincinnati, OH


  1. Awosika-Olumo AI, Trangle K, Fallon F Jr. Microorganism induced dermatosis in workers exposed to metal working fluid. Occup Med 2003;53:35-40


  1. Li K, Aghazadeh F, Hatipakarasulu S, Ray TG. Health risks from exposure to metalworking fluids in machining and grinding operations. Inter J Occup Safety and Ergonomics 20003;9:75-95


  1. Arif AA, Whitehead LW, Delclos GL, Tortolero SR, Lee ES. Prevalence and risk factors of work related asthma by industry among United States workers; data from third national health and nutrition examination survey (1988-94). Occup Environ Med. 2002;59:503-4


  1. Piacitelli GM, Sieber WK, O’Brien DM, Hughes RT, Glaser RA, Catalano JD. Metal working fluids exposures in small machine shops: an overview. AIHAJ 2001;62:356-70


  1. Kennedy SM, Chan-Yeung M, Teschke K, Karlen B. Change in airway responsiveness among apprentices exposed to metal working fluids. Am J Respiratory Critical Care Med 1999;159:87-93


  1. Zacharisen MC et al., the spectrum of respiratory disease associated with exposure to metal working fluids. J Occup Environ Med 1998; 40:640-7


  1. Greaves IA et al. Respiratory health of automobile workers exposed to metal working fluid aerosols: respiratory symptoms. Am J Industrial Med 1997;32:450-9


  1. Rosenman KD, Reilly MJ, Kalinowski D. Work-related asthma and respiratory symptoms among workers exposed to metal working fluids. Am J Industrial Med 1997; 32:325-31


  1. Kreiss K, Cox-Ganser J. Metalworking fluid associated hypersensitivity pneumonitis: a workshop summary. Am J Industrial Med 1997;32:423-32


  1. Kriebel D et al. A field investigation of the acute respiratory effects of metal working fluids. I. Effects of aerosol exposures. Am J Industrial Med 1997;31:756-66


  1. Massin N. et al. Airway responsiveness, respiratory symptoms, and exposures to soluble oil mist in mechanical workers. Occupational Environ Med 1996;53:748-52