Mineral oil metal working fluids (MWFs)—development of practical criteria for mist sampling

Abstract

Not all mineral oil metalworking¯uids (MWFs) in common use form stable airborne mists which can be sampled quantitatively onto a ®lter. This much has been known for some time but no simple method of identifying oils too volatile for customary ®lter sampling has been developed. Past work was reviewed and experiments were done to select simple criteria which would enable such oils to be identi®ed. The sampling eciency for a range of commercial mineral oil MWF were assessed by drawing clean air through spiked ®lters at 2 l. min À1 for periods up to 6 h before analysis. The physical properties of MWF are governed by their composition and kinematic viscosity was found to be the most practical and easily available index of the potential for sample loss from the ®lter. Oils with viscosities greater that 18 cSt (at 408C) lost less than 5% of their weight, whereas those with viscosities less than 18 cSt gave losses up to 71%. The losses from the MWF were mostly aliphatic hydrocarbons (C 10 ±C 18), but additives such as alkyl benzenes, esters, phenols and terpene odorants were also lost. The main recommendation to arise from the work is that ®lter sampling can be performed on mineral oils with viscosities of 18 cSt (at 408C) or more with little evaporative losses from the ®lter. However, sampling oils with viscosities less than 18 cSt will produce results which may signi®cantly underestimate the true value. Over a quarter of UK mineral oil MWFs are formulated from mineral oils with viscosities less than 18 cSt (at 408C). The problem of exposure underestimation and inappropriate exposure sampling could be widespread. Further work is being done on measurement of mixed phase mineral oil mist exposure. Crown

Exposure to metalworking fluids and respiratory and dermatological complaints in a secondary aluminium plant

“…We only detected MWF vapour in the Cold Rolling Mills, which exposure level exceeded 5 mg/m 3 . Vapour samples will not only have sampled hydrocarbon vapours originating from the oil only but also from any other source in the workplace (Simpson et al 2000;Simpson 2003). On the other hand, MWF vapour could also been lost from glass Wbre Wlters samples of oil mist from light MWF during sampling (Górny et al 2004;Simpson et al 2000;Simpson 2003).…”

“…Rather than describing a speciWc chemical composition, the term describes a function, that of providing lubricity in order to remove friction, and controlling thermal distortion by carrying away the heat, thereby improving the machinability. At the same time, they extend tool life, reduce power consumption, and remove metal chips (Gauthier 2003;Simpson et al 2000). MWF are divided into four categories: insoluble, soluble, synthetic and semi-synthetic Xuids (Fox et al 1999;Tolbert 1997).…”

“…Dermatologic problems such as acne, folliculitis, hyperpigmentation, granuloma, teleangiectasia, irritant or allergic contact eczema and scars caused by droplets of hot oil, are the most commonly reported among metal workers (Cruickshank and Squire 1993;Dejans et al 2001;Pryce et al 1989;Simpson et al 2000). MWF particles smaller than 5 m can reach the alveoli and cause problems of the upper and lower respiratory tract.…”

“…MWF particles smaller than 5 m can reach the alveoli and cause problems of the upper and lower respiratory tract. These include airway hyper-responsiveness (mucus production, runny or stuVed nose, sinusitis), burning or redness of eyes, wheezing, dyspnea), epistaxis, sore throat, chronic cough, (chronic) bronchitis, pneumonia, occupational asthma, emphysema and lipoid pneumonitis/extrinsic allergic alveolitis (Ameille et al 1992;Dalbey and Biles 2003;Fox et al 1999;Pillière and Rousselin 1992;Rosenman et al 1997;Simpson et al 2000). Studies indicated that these respiratory complaints also appear at low oil mist concentrations (below 5 mg/m 3 ) (Cohen and White 2006;Pillière and Rousselin 1992).…”

Evaporation of Liquid Semi-Volatile Aerosols Collected on Fibrous Filters

“…More recently, other studies have focused on the re-entrainment in vapor form of cutting oils deposited on fibrous filters, when treating metalworking oil mist (Cooper et al 1998;Riss et al 1999) or during control sampling of ambient concentrations of aerosols (Volckens et al 1999;Simpson et al 2000;Volckens et al 2002;Park et al 2003;Simpson et al 2003;Verma et al 2006;Lim et al 2008).…”