Dermal permeation of biocides and aromatic chemicals in three generic formulations of metalworking fluids.

Metalworking fluids (MWF) are complex mixtures consisting of a variety of components and additives. A lack of scientific data exists regarding the dermal permeation of its components, particularly biocides. The aim of this study was to evaluate the dermal permeation of biocides and other aromatic chemicals in water and in three generic soluble oil, semi-synthetic, and synthetic MWF types in order to evaluate any differences in their permeation profiles.

Metalworking fluid mist occupational exposure limits: a discussion of alternative methods.

NIOSH published a recommended exposure limit (REL) for metalworking fluids (MWF) in 1998 that was designed to prevent respiratory disorders associated with these industrial lubricants. The REL of 0.4 mg/m(3) (as a time-weighted average for up to 10 hours) was for the fraction of aerosol corresponding to deposition in the thoracic region of the lungs.

History and results of the two inter-laboratory round robin endotoxin assay studies on cotton dust.

Background: In the US cotton industry, airborne cotton dust levels are regulated, and other countries are moving to specify safety limits for airborne endotoxins. There is concern about potential respiratory health hazards associated with agricultural and other organic dusts. In laboratories, ranking which samples have high and low levels of endotoxin is usually in good agreement between laboratories.

Effects of fluid composition on mist composition.

In a reported study, mists of selected synthetic metalworking fluids were generated in laboratory experiments by two processes, nebulization (atomization) and air sparging (bubbling). Short-chain fatty acid species were determined by in situ trimethylsilyl derivatization. Comparison of relative amounts of the short-chain acids collected from mists generated by nebulization with those generated by sparging showed that the sparged mists had significantly higher amounts of neodecanoic, nonanoic, and dodecanedioic acids.

Second inter-laboratory study comparing endotoxin assay results from cotton dust.

Previously, a large two-part inter-laboratory round robin endotoxin assay study was completed. This first study showed that when cotton dust samples, which are practically identical, are assayed for endotoxin that the intra- laboratory results had a very small variation while intra-laboratory results of the sample had a very high variation. In the first part of the study, each laboratory followed its own in-house assay protocol; but in the second part of the study, when the extraction protocol was standardized, the inter-laboratory results showed a lower variation, which suggested that with further standardization, further reduction of differences between laboratories might be achieved in order that results between laboratories would become more comparable.