tailieunhanh - Cutting Fluids Part 5

Tham khảo tài liệu 'cutting fluids part 5', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Cutting Fluids 421 a Folliculitis Detail of Folliculitis b Tarwart d Pigmentation Sessile wart c Hyper-Keratosis Figure 211. Some typical but extreme skin disorders - attributed to exposure to cutting fluids. Courtesy of Castrol Industrial 422 Chapter 8 Many other skin conditions can occur and their causes can emanate from a number of MWF sources - going beyond the current scope and objectives of this chapter. Although through the application of barrier and conditioning creams together with clean and suitable protective clothing coupled to good washing facilities these factors will inevitably lessen the possibility of allergic reactions and skin disorders. Tumours and Cancerous Effects However less well known than the allergic and skin condition previously mentioned are the other more serious debilitating health effects on the machine tool personnel exposed to MWF s. Industrial experience suggests that continuous and long exposure to certain mineral oils can give rise to skin thickening known as keratosis whereby warty-elevations . see Fig. 211b can slowly develop over a period of some years. Hence these warts will either remain as they are disappear or in the worse case scenario become malignant. A considerable volume of research in both the chemical and biological fields has been undertaken in particular into the effects of mineral oils in cutting fluids and their affect on worker s health. Mineral oils may contain carcinogens - chemical compounds which are active in causing cancer with currently a number of these compounds having been identified. They occur in the main as polycyclic aromatic hydrocarbons and when present in modern refined mineral oils exist in extremely small proportions - making their positive chemical identification exceedingly difficult to define. Oil refinement by acid treatment has now been replaced by more modern refining techniques including solvent-refined treatment and hydrogeneration - greatly reducing the undesirable proportions of